Prescribing Safety Assessment Flashcards
What makes a safe and legal prescription? Must be what?
Date, identification of the patient, name of the drug, formulation, dose, frequency of administration, route of administration, amount to be supplied (GP only,) prescribers signature, must be legible
Legible, unambiguous, an approved name, in capitals, without abbreviations, signed, if ‘as required’: 2 instructions- 1) indication, 2) maximum frequency, if antibiotic= include the indication and stop/ review date
Don’t get marks for doing what if the prescription written is wrong?
Signing name and date
What does an enzyme inducer do? What does an enzyme inhibitor do?
They increase P450 enzyme activity, hastening the metabolism of other drugs with the result that they exert a reduced effect- thus a patient will require more of some other drugs in the presence of an enzyme inducer
Decrease P450 enzyme activity–> increased levels of other drugs e.g. warfarin can cause a dangerous rise in INR
What are the most common enzyme inducers? Inhibitors? What happens if atorvastatin is given with macrolides?
PC BRAS: phenytoin/ pioglitazone, carbamazepine, barbiturates, rifampicin, alcohol, sulfonylureas, cigarette smoke, solvents, some antimicrobials
AODEVICES: allopurinol/ amiodarone, omeprazole, disulfiram, erythromycin, valproate, isoniazid, ciprofloxacin, ethanol, sulphonamides/ SSRIs
Grapefruit juice, cimetidine- think CEMENT, macrolides e.g. erythromycin/ clarithromycin
Increase muscle pain, tenderness and/or dark coloured urine
Patients on long-term corticosteroids e.g. prednisolone should be given what at induction of anaesthesia?
IV steroids to prevent profound hypotension
Drugs to stop before surgery?
I LACK OP: insulin- metformin(will cause lactic acidosis,) lithium, anticoagulants/ antiplatelets, COCP/ HRT, K+- sparing diuretics, oral hypoglycaemics- would cause hypoglycaemia(sliding scale should be started instead,) perindopril and other ACE-i
When to stop COCP + HRT before surgery? Lithium? K+-sparing diuretics and ACE-i? Anticoagulants and antiplatelets? Oral hypoglycaemic drugs and insulin?
4 weeks
Day before
Day of surgery
Variable
Variable
Mnemonic for prescribing essentials?
PReSCRIBER: patient details= name, DOB and hospital number, reaction i.e. allergy plus the reaction, sign the front of the chart, check for CI to each drug, route, IV fluids if needed, blood clot prophylaxis if needed, antiEmetic if needed and pain Relief if needed
What are never events?
Serious and avoidable medical errors for which there should be preventative measures in place to stop their occurrence
What are biological medicines?
Those made by or derived from a biological source using biotechnology processes such as recombinant DNA technology- size, complexity and how they’re produced may result in a degree of natural variability in molecules of the same active substance particularly in different batches of the medicine e.g. insulin, MABs
What is a biosimilar medicine? How should they be prescribed? Adverse reaction reports should clearly state what? Report using what?
A biological medicine that is highly similar and clinically equivalent to an existing biological medicine that has already been authorised in the EU- active substance is similar but not identical to the originator biological medicine
Choice to prescribe lies with the clinician in consultation with the patient- must be prescribed by brand name and the brand name specified should be dispensed
Brand name and batch number
To the MHRA through the Yellow Card Scheme
Drugs available as biosimilar drugs?
Adalimumab
Bevacizumab
Enoxaparin sodium
Epoetin alfa
Epoetin zeta
Etanercept
Filgrastim
Follitropin alfa
Infliximab
Insulin glargine
Insulin lispro
Rituximab
Somatropin
Teriparatide
Trastuzumab
When are oral syringes supplied? How should they be labelled?
When oral liquid medicines are prescribed in doses other than multiples of 5ml
The oral syringe is marked in 0.5 mL divisions from 1 to 5 mL to measure doses of less than 5 mL (other sizes of oral syringe may also be available). It is provided with an adaptor and an instruction leaflet. The 5–mL spoon is used for doses of 5 mL (or multiples thereof)
Oral/ enteral in a large font size- practitioner’s responsibility
What might the presence of propylene glycol interact with? High content of sodium considered as what?
Disulfiram and metronidazole
Containing ≥ 17 mmol sodium= 20% WHO recommended max daily dietary intake for an adult
How to prevent adverse reactions?
Never use any drug unless there is a good indication. If the patient is pregnant do not use a drug unless the need for it is imperative;
Allergy and idiosyncrasy are important causes of adverse drug reactions. Ask if the patient had previous reactions to the drug or formulation;
Ask if the patient is already taking other drugs including self-medication drugs, health supplements, complementary and alternative therapies; interactions may occur;
Age and hepatic or renal disease may alter the metabolism or excretion of drugs, so that much smaller doses may be needed. Genetic factors may also be responsible for variations in metabolism, and therefore for the adverse effect of the drug; notably of isoniazid and the tricyclic antidepressants;
prescribe as few drugs as possible and give very clear instructions to the elderly or any patient likely to misunderstand complicated instructions;
Whenever possible use a familiar drug; with a new drug, be particularly alert for adverse reactions or unexpected events;
consider if excipients (e.g. colouring agents) may be contributing to the adverse reaction. If the reaction is minor, a trial of an alternative formulation of the same drug may be considered before abandoning the drug;
Warn the patient if serious adverse reactions are liable to occur.
When is a drug reaction likely to be caused by drug allergy?
The reaction occurred while the patient was being treated with the drug, or
The drug is known to cause this pattern of reaction, or
The patient has had a similar reaction to the same drug or drug-class previously
Drugs capable of causing oral ulceration?
Cytotoxic drugs, e.g. methotrexate. Other drugs capable of causing oral ulceration include ACE inhibitors, gold, nicorandil, NSAIDs, pancreatin, penicillamine, proguanil hydrochloride, and protease inhibitors
Lichenoid eruptions associated with what drugs? Candidiasis can complicate treatment with what?
ACE inhibitors, NSAIDs, methyldopa, chloroquine, oral antidiabetics, thiazide diuretics, and gold
Antibacterials and immunosuppressants- occasional for corticosteroid inhalers
Chlorhexidine mouthwash can cause what? Iron salts in liquid form can do what? Intrinsic staining of the teeth most commonly caused by what? CI in who?
Brown staining of the teeth- can be removed by polishing
Stain the enamel black
Tetracyclines during pregnancy, in breast-feeding women, in children under 12 years
Excessive ingestion of fluoride leads to what?
Dental fluorosis with mottling of the enamel and areas of hypoplasia or pitting, mild mottling if dose is too large for child’s age
Who is at risk of osteonecrosis of the jaw?
Those receiving bevacizumab or sunitinib for cancer, IV bisphosphonates> those receiving oral for osteoporosis or Paget’s disease
Gingival overgrowth is a SE of what? Most common effect on the salivary glands? Those at greater risk of dental caries and oral infections particularly candidiasis?
Phenytoin and sometimes of ciclosporin or of nifedipine
To reduce flow(xerostomia)
Those with poor oral hygiene / persistently dry mouth
Drugs implicated in xerostomia?
Antimuscarinics, antidepressants, alpha-blockers, antihistamines, antipsychotics, baclofen, bupropion hydrochloride, clonidine hydrochloride, 5HT1 agonists, opioids, tizanidine, diuretics
Drugs that can increase saliva production? Pain in salivary glands? Swelling?
Clozapine, neostigmine
Some antihypertensives e.g. clonidine hydrochloride, methyldopa. vinca alkaloids
Iodidies, antithyroid drugs, phenothiazines and sulfonamides
Drugs implicated in decreased taste acuity or alteration in taste sensation?
Amiodarone hydrochloride, calcitonin, ACE inhibitors, carbimazole, clarithromycin, gold, griseofulvin, lithium salts, metformin hydrochloride, metronidazole, penicillamine, phenindione, propafenone hydrochloride, protease inhibitors, terbinafine, and zopiclone
When is the neonatal period? Child? What should be avoided in children? Doses of drugs based on what? Many are standardised by what?
First 28 days of life, 1 month- 17 years
IM injections
Age ranges, body-weight in kg
Weight, sometimes body surface area in metres 2
What drugs are excreted in the bile unchanged and can accumulate in patients with intrahepatic or extrahepatic obstructive jaundice?
Fusidic acid, rifampicin
Reduced hepatic synthesis of blood-clotting factors indicated by a prolonged prothrombin time increases sensitivity to what? What drugs can further impair cerebral function and precipitate hepatic encephalopathy? Oedema and ascites in CLD exacerbated by what?
Oral anticoagulants such as warfarin sodium and phenindione
Sedative drugs, opioid analgesics, diuretics producing hypokalaemia, drugs causing constipation
NSAIDs and corticosteroids (give rise to fluid retention)
Why do issues arise in patients with reduced renal function? How to avoid these?
Reduced renal excretion of a drug or its metabolites may cause toxicity;
sensitivity to some drugs is increased even if elimination is unimpaired;
many side-effects are tolerated poorly by patients with renal impairment;
some drugs are not effective when renal function is reduced.
By reducing the dose or by using alternative drugs
The effects of renal impairment on drug elimination usually stated in terms of what? Exceptions to the use of eGFR where Cr Cl is recommended include what?
Creatinine clearance
Toxic drugs, in elderly patients and in patients at extremes of muscle mass
Formula for using creatinine clearance? When should CrCl be used?
Cockcroft and Gault formula: (140-age) x weight x constant/ serum creatinine- age in years, weight in kg, serum creatinine in micromol/ litre, constant= 1.23 in men, 1.04 in women
As an estimate of renal function for direct-acting oral anticoagulants (DOACs), and drugs with a narrow therapeutic index that are mainly renally excreted
When should renal function and drug dosing be reassessed?
In situations where eGFR and/or CrCl change rapidly, such as in patients with AKI
When is caution advised when using eGFR or CrCl to estimate renal function?
During AKI- as serum creatinine levels lag behind the development of the injury and progress of recovery. As creatinine rises, estimates of GFR will overestimate renal function and as creatinine falls and kidney function improves, estimates of GFR will underestimate renal function
What formula is recommended for estimating GFR and calculating drug doses in most patients with renal impairment? Who should use this to routinely report eGFR?
CKD-EPI- adjusted for body surface area and utilises serum creatinine, age, sex and race as variables
Clinical laboratories
How does muscle mass affect eGFR? When should creatinine clearance or absolute glomerular filtration rate be used to adjust drug doses according to BMI?
Reduced muscle mass will lead to overestimation of GFR and increased muscle mass will lead to underestimation of the GFR
In patients with a BMI less than 18 kg/m2 or greater than 40 kg/m2
How is ideal and actual body weight used in CrCl?
Ideal body weight should be used to calculate the CrCl. Where the patient’s actual body weight is less than their ideal body weight, actual body weight should be used instead
How is ideal body weight calculated? Absolute GFR?
Constant + 0.91 (Height - 152.4)
Constant = 50 for men; 45.5 for women
Height in centimetres
eGFR x (individual’s body surface area / 1.73)
Preferred method for estimating renal function in elderly patients aged 75 years and over? What is considered when thinking about using CKD-EPI?
Cockcroft and Gault formula
Muscle mass
When is the period of greatest risk during the 1st trimester? What can inhibit the infant’s sucking reflex? Lactation?
From the 3rd-11th week
Phenoarbital, bromocriptine
What are STOPP/ START criteria?
Evidence-based criteria used to review medication regimens in elderly people
Common adverse reactions in elderly patients?
Confusion- almost any of the commonly used drugs
Constipation- antimuscarinics and many tranquilisers
Postural hypotension and falls- diuretics and many psychotropics
Hypoalbuminaemia in severe liver disease is associated with what? E.g.?
Reduced protein binding and increased toxicity of some highly protein-bound drugs such as phenytoin and prednisolone
Efficacy and toxicity are closely related to what? Total daily maintenance dose of a drug can be reduced either by what or what? What is prolonged in renal impairment?
Plasma- drug concentration
Reducing the size of the individual doses or by increasing the interval between doses
The plasma half-life of drugs excreted by the kidney- it can take many doses at the reduce dosage to achieve a therapeutic plasma concentration
How does the BNF identify drugs in relation to breast- feeding?
That should be used with caution or are contra-indicated in breast-feeding;
that can be given to the mother during breast-feeding because they are present in milk in amounts which are too small to be harmful to the infant;
that might be present in milk in significant amount but are not known to be harmful
Who may become hypotensive under the stress of a dental visit?
Those with adrenal insufficiency
What can be considered for moderate pain in palliative care? Alternatives to morphine? For pain–> bone mets?
Codeine phosphate or tramadol hydrochloride
Transdermal buprenorphine/ fentanyl, hydromorphone hydrochloride, methadone hydrochloride, oxycodone hydrochloride
Radiotherapy, bisphosphonates, radioactive isotopes of strontium chloride
Options for neuropathic pain in palliative care? Due to nerve compression?
Gabapentin/ pregabalin, tricyclic antidepressant, ketamine under specialist supervision
Dexamethasone/ nerve blocks or regional anaesthesia when localised to a specific area
How is oral morphine given?
IR prep 4-hourly/ MR 12-hourly in addition to rescue doses- between regular doses additional dose of IR should be given + 30 minutes before activity that causes pain
Standard dose of strong opioid for breakthrough pain? Increments of rescue morphine doses should not exceed what? Standard dose of immediate-release morphine? Once pain is controlled, patients can be transferred to what?
1/10th- 1/6th repeated every 2-4 hours as required
1/3 to 1/2 of the total daily dose every 24 hours
30mg 4-hourly, some up to 200mg 4-hourly or 100mg 12-hourly modified release/ 600mg
The same total 24-hour dose of morphine given as the modified- release prep for 12 hourly
When is the first dose of modified-release prep for 12-hourly morphine given? Monitor for what?
Within 4 hours of the immediate-release prep
Constipation, and N&V
Equivalent doses of opioid analgesics?
100mg codeine, 3mg diamorphine, 100mg dihydrocodeine, 2mg hydromorphone, 10mg morphine PO, 5mg morphine IM/ IV/ SC, 6.6mg oxycodone PO, 100mg tramadol PO
Equivalent parenteral dose to oral dose? Route if can’t swallow? Equivalent SC dose of diamorphine hydrochloride to oral morphine? Other morphine route?
Half of oral dose, SC infusion- diamorphine sometimes preferred as more soluble, can be given in a smaller volume
1/3
Rectal
Who are transdermal preps of fentanyl and buprenorphine not suitable for?
Acute pain/ in those whose analgesic requirements are changing rapidly because the long time to steady state prevents rapid titration of the dose
Reduce the calculated equivalent dose of the new opioid by how much compared to morphine? Morphine–> buprenorphine patch doses vs ‘numbers’?
1/4 to 1/2
Morphine 12mg= ‘5’ patch
24mg= ‘10’
36mg= ‘15’
48mg= ‘20’
84mg= ‘35’
126mg= ‘52.5’
168mg= ‘70’
Formulations of transdermal patches are available as what options? Morphine–>fentanyl patch doses vs ‘numbers’?
72-hourly, 96-hourly and 7-day patches
30mg= ‘12’
60mg= ‘25’
120mg= ‘50’
180mg= ‘75’
240mg= ‘100’
Anorexia in palliative care can be helped by what? Bowel colic and excessive respiratory secretions? Given how often?
Prednisolone or dexamethasone
SC injection of hyoscine hydrobromide, hyoscine butylbromide or glycopyrronium bromide- every 4 hours/ continuous infusion if sx persist, care to avoid dry mouth
Capillary bleeding in palliative care treated with what? Tx discontinued when? Alternative? Consider what to prevent bleeding associated with prolonged clotting in liver disease in severe chronic cholestasis?
Tranexamic acid by mouth- one week after the bleeding has stopped/ continued at a reduced dose/ gauze soaked in tranexamic acid 100mg/mL or adrenaline solution 1mg/mL
Parenteral/ water-soluble oral vitamin K
What can be given for constipation in palliative care?
Faecal softener with a peristaltic stimulant/ lactulose solution with a senna prep, methylnaltrexone bromide for opioid-induced constipation
How to prevent convulsions in patients with cerebral tumours or uraemia? When oral medication is not possible?
Phenytoin or carbamazepine
Diazepam given rectally/ phenobarbital by injection
Dry mouth associated with candidiasis can be tx how in palliative care? Tx for dysphagia? Breathlessness at rest? Dyspnoea ass w/ anxiety? If there’s bronchospasm or partial obstruction?
Oral preps of nystatin or miconazole/ fluconazole
Dexamethasone
Regular oral morphine in carefully titrated doses
Diazepam
Dexamethasone
What can be given for fungating tumours in palliative care?
Regular dressing and antibacterial drugs; systemic tx with metronidazole to reduce malodour, topical metronidazole= also used
What can be given for pain of bowel colic in palliative care? Gastric distension due to pressure on the stomach?
Loperamide hydrochloride/ hyoscine hydrobromide given sublingually
SC injections of hyoscine butylbromide, hyoscine hydrobromide and glycopyrronium bromide
Antacid w/ an antiflatulent and a prokinetic e.g. domperidone
Hiccup due to gastric distension in palliative care tx?
Antacid with an antiflatulent/ metoclopramide hydrochloride by mouth or by SC or IM injection, baclofen or nifedipine/ chlorpromazine hydrochloride
What can be given for insomnia in palliative care? Intractable cough? Pain of muscle spasm?
Benzos such as temazepam
Moist inhalations/ regular admin of oral morphine
Muscle relaxant such as diazepam or baclofen
1st line therapy for N&V? May occur with what particularly in the early stages?
Prokinetic- metoclopramide hydrochloride or haloperidol (usually only for first 4 or 5 days)
Opioid therapy
Metoclopramide hydrochloride is used by mouth for N&V associated with what? Haloperidol? Cyclizine? Levomepromazine? Dexamethasone?
Gastritis, gastric stasis and functional bowel obstructions
Most metabolic causes of vomiting e.g. hypercalcaemia, renal failure
N&V due to mechanical bowel obstruction, raised ICP, and motion sickness
By mouth/ SC at bedtime (review antiemetics every 24 hours)
Pruritus in palliative care tx? Headache due to raised ICP?
Emollients, colestyramine
Dexamethasone before 6pm to reduce the risk of insomnia
Restlessness and confusion in palliative care tx? What should be considered?
Antipsychotic- e.g. haloperidol or levomepromazine by mouth/ SC injection both repeated every 2 hours if required
A regular maintenance dose given x2 daily by mouth / SC injection; continuous infusion device
Indications for parental administration of drugs in palliative care?
The patient is unable to take medicines by mouth owing to nausea and vomiting, dysphagia, severe weakness, or coma
there is malignant bowel obstruction in patients for whom further surgery is inappropriate (avoiding the need for an intravenous infusion or for insertion of a nasogastric tube)
Occasionally when the patient does not wish to take regular medication by mouth
Antiepileptic of choice for continuous SC infusion to prevent convulsions? What else?
Midazolam
Haloperidol and levomepromazine- sedation can limit the dose of levopromazine
How can ocreotide be used in palliative care?
By SC infusion to reduce intestinal secretions and to reduce vomiting due to bowel obstruction
What can be mixed with diamorphine for a SC infusion in a strength of up to 250mg/mL? Why should SC infusion solution be monitored regularly?
Cyclizine, dexamethasone, haloperidol, hyoscine butylbromide, hyoscine hydrobromide, levomepromazine, metoclopramide, midazolam
To check for precipitation and to ensure that the infusion is running at the correct rate
Drugs causing delirium/ acute confusion in the elderly? Dehydration? Renal impairment? Liver impairment?
Sedative hypnotics- benzos like diazepam, zopiclone, analgesics, anticholinergics, anticonvulsants, antidepressants, antipsychotics, metoclopramide, electrolyte imbalance e.g. hyponatraemia from thiazide like diuretics
Diuretics
Withheld metformin
NSAIDs, corticosteroids worsening oedema/ ascites, rifampicin
Issues encountered with syringe drivers?
If the subcutaneous infusion runs too quickly check the rate setting and the calculation;
if the subcutaneous infusion runs too slowly check the start button, the battery, the syringe driver, the cannula, and make sure that the injection site is not inflamed;
if there is an injection site reaction make sure that the site does not need to be changed—firmness or swelling at the site of injection is not in itself an indication for change, but pain or obvious inflammation is
Groups of drugs used to treat Parkinson’s?
Levodopa drugs & dopa-decarboxylase inhibitor e.g. Co-careldopa, Madopar
COMT inhibitors e.g. entacapone, tolcapone
MAO inhibitors e.g. selegiline, rasagiline
Dopamine receptor agonists e.g. ropinirole (modified release/ immediate release,) pramipexole
What is in co-careldopa? Madopar? Function of levodopa? Carbidopa? Benserazide?
Levodopa + carbidopa
Levodopa + benserazide
Helps to replace the missing dopamine/ prevents levodopa from being broken down before reaching the brain/ prevents levodopa changing to dopamine in the bloodstream- more can enter the brain
What is adherence? What is compliance? Concordance?
The extent to which the patient’s medicines- taking behaviour matches agreed recommendations from the prescriber
The extent to which the patient’s medicines-taking behaviour matches the prescriber’s recommendations
The belief that the prescriber and the patient must come to an agreement regarding therapeutic decisions- more likely to result in adherence with the prescriber’s recommendations
WHO has determined that what 5 interacting dimensions affect adherence?
Social/ economic factors, health system/ healthcare team factors, therapy-related factors, patient-related factors, condition-related factors
Thiazide diuretics can cause what? Systemic corticosteroids may alter what? Prochlorperazine can cause what?
Hyperuricaemia which may exacerbate gout in suspectible patients
Mood and behaviour- needs a therapy review, reduction or discontinuation would depend on the indication for tx
Extra-pyramidal side effects e.g. dystonia, review & switch if possible
May be cheaper for patients to buy a what if they have to pay for more than 11 prescribed medicines each year/>3 medicines in 3 months?
A Prescription Pre-Payment Certificates (PPC)- spreads the cost of prescriptions across 12 months (or 3 months)
What is the New Medicine Service (NMS)? Patients prescribed a new medicine on one of the following are eligible for the NMS?
Pharmacy-based intervention which provides support for people with long-term conditions who are newly prescribed a medicine
Asthma & COPD, T2DM, antiplatelet/ anticoagulant therapy, HTN
Factors affecting bioavailability? Key pharmacokinetic parameters that describe bioavailability? What is steady-state concentration?
Route of administration, properties of the drug, plasma-protein binding, metabolism, elimination
Area under the curve(AUC,) peak plasma concentration (Cmax,) time to peak plasma concentration (Tmax)
When the inflow of the drug into plasma is equal to the rate of removal
How is the volume of distribution/ apparent volume of distribution (Vd) worked out? What will it depend on?
Total amount of drug in the body(X)- mg/ plasma-drug concentration (Cp)- mg/ litre- typically reported in (ml or litre)/ kg body-weight
The physiochemical properties of the drug and the individual’s patient’s body composition
Which drugs have a low Vd? Larger Vd?
Highly water soluble ones like gentamicin, atenolol, and insulin/ extensively protein-bound e.g. warfarin- stay in the plasma
Highly lipid soluble e.g. digoxin, morphine and diazepam- go out of the plasma into tissues and organs
Acidic drugs bind to what? Basic drugs bind to what? Acronym for hepatic clearance? Renal clearance? Total body clearance is calculated how?
Albumin
Alpha1-acid-glycoprotein
CLH, CLR, CL= CLH + CLR
The pharmacokinetics of a drug can be defined using how many parameters? How is the elimination rate constant(k) calculated?
3: volume of distribution (vd,) elimination half-life(t1/2,) clearance(Cl)
k= Cl/ Vd- the greater the fraction of drug removed in unit time, the shorter the half-life, half-life varies inversely with elimination rate constant (k)
Vd can be significantly altered by what? Vd equation? Half-life?
Alterations in plasma-protein concentrations, hepatic disease; and changes in patient physiology- these help determine the time taken for a drug to reach steady-state concentration
Vd= X/ Cp, X= amount of drug in body and Cp= plasma concentration
Half-life= 0.693/k where 0.693 is ln2, the natural logarithm of 2
What can the therapeutic window help to determine?
Whether a drug concentration is ineffective, effective or toxic- monitoring needed for drugs with a narrow therapeutic window e.g. digoxin, gentamicin, lithium salts, vancomycin
Approximately how many half lives needed to excrete 97% of a drug?
5 half-lives
Chemical formula for a drug with its receptor? The proportion of receptors occupied by a drug is equal to what? What is Kd?
D+R<–> DR
p= [D]/ [D] + Kd- the Hill-Langmuir equation
The ratio k-/k+ (the forward rate or reverse rate constant)
Most antagonists are what?
Competitive- increasing this concentration right-shifts the curve, decreasing binding for a fixed agonist concentration
What is affinity? Efficacy?
The tendency of a molecule to bind to a receptor following occupancy of this receptor
How well an agonist achieves a response- it can encompass a very complex pathway
What is the potency of a drug often described by?
The concentration/ dose that is able to elicit 50% of the maximal response i.e. the EC50/ ED50- a drug with higher potency achieves that size of response at a lower concentration
What is a partial agonist? E.g.?
A drug that has a lower maximal response resulting from lower efficacy
Many of the ‘beta blockers’
What do allosteric modulators do?
Bind to proteins at sites other than the binding site for the principal agonist- can alter the affinity of the binding site for its agonists/ change the efficacy of the response when the agonist binds
Can be positive- increase the potency of the agonists/ negative- decrease the potency of an agonist
What does early pregnancy body-weight relate to? Actual body weight? Used when?
The patient’s weight in their first trimester
The weight you get when you stand the patient on a set of scales- product requires the dose to be calculated on a ‘per kilogram’ basis but does not specify a type of weight to use
What is ideal body weight derived from? How is lean body weight calculated? What do drugs distributed in water need to be dosed based on? Distribute into fat? For patients at the extremes of the weight range?
Insurance date
By subtracting body fat weight from actual body weight
Lean or ideal body weight; actual body weight
Seek further information on appropriate dosing, particularly of those drugs with a narrow therapeutic index
Equations for calculating a child’s weight in 0-12 months, 1 to 5 years, 6-12 years?
(0.5 x age in months) + 4(kg)
(2 x age in years) + 8(kg)
(3x age in years) + 7 (kg)
What does a 1% w/w preparation mean? Hydrocortisone 0.5% w/w? 1% w/v solution? 1% v/v solution?
1g of drug in 100g of the final product
0.5g of hydrocortisone in 100g of the cream
1g of drug in 100mg of the final product
1ml of liquid in 100ml of the final product
1:1000 represents what? 1:10,000? Adrenaline 1 in 1000? 1 in 200,000?
1 gram in 1000ml/ 1 gram in 10,000ml
1 mg per ml , 5 mcg per ml
How many lbs in a stone? Grams in a pound? How many kg is 1 stone? Inches in one foot? Mm in 1 inch? Mm in 1 foot?
14 pounds, 450g, 6.35kg
12 inches, 25.4mm, 304.8 mm
Up to what age is classed as a neonate? Infant? Adolescent?
1 month, up to 1 year (,then 1-5 years, 6-11 years,) 12-16 years
Doses of chlordiazepoxide, lorazepam, nitrazepam and temazepam that are equivalent to 5mg diazepam?
12.5mg, 500mcg, 5mg, 10mg
What dose does hydrocortisone compare to prednisolone?
x4 e.g. 100mg hydrocortisone= 25mg prednisolone
Max body weight to be used for acetylcysteine? Preferably diluted in what? First dose is given over how long in how much of glucose 5%? Second dose? Third and final dose? Doses needed each dose? Alternative?
110kg- even if the patient is heavier i.e. the dose is capped
Glucose 5%- NaCl 0.9% if glucose 5% is not suitable
1 hour in 200ml of glucose 5%, 2) the next 4 hours in 500ml glucose 5%, 3) 3rd and final= over the next 16 hours in 1 litre of glucose 5%
1) 150mg/kg, 2) 50mg/ kg, 3) 100mg/ kg= 300mg/ kg over 21 hours
In millilitres according to defined weight bands
Acetylcysteine is most useful given in what time period?
8 hours
In clinical practice, the dose of immunoglobulins is often rounded to what?
The nearest 5g
How do you calculate the volume of a parenteral drug needed to be administered or added to an infusion?
(Dose prescribed x volume of solution)/ amount of drug in solution
What is warfarin the anticoagulant of choice for? What does dabigatran inhibit? Rivaroxaban, apixaban and edoxaban?
The prevention of thromboembolic events in patients with mechanical heart valves and valvular AF and patients in end-stage renal failure
Thrombin
Activated factor Xa
Contraindications for warfarin?
Malignancy- use heparin/ a DOAC, known hypersensitivity to warfarin, haemorrhagic stroke, clinically significant bleeding, potential bleeding lesions, uncorrected major bleeding, pregnancy- risk of congenital malformations and fetal death, within 72 hours of major surgery with the risk of severe bleeding, within 48 hours postpartum, uncontrolled severe HTN, patient factors, drugs with increased risk of bleeding- NSAIDs, antiplatelets, enzyme inhibitors
INR treatment targets when taking warfarin? How long for?
2-3 for tx of VTE, AF, mitral valve disease and inherited symptomatic thrombophilia
2.5-3.5 for mechanical heart valves
Usually lifelong - exception= tx of VTE if temporary RFs prior to clot–> 3 months, if permanent- 6 months
How long may warfarin take to achieve an INR within the therapeutic range? What does it induce? How is this addressed?
5 days
A hypercoagulable state- suppression of protein C occurs quicker than that of the coagulation factors(shorter half-life)
If patient develops an acute VTE and high risk of further thrombosis- admin of heparin considered for at least 5 days until INR within therapeutic range
Most common SE of warfarin? Exclude what following a head injury? Other SEs?
Haemorrhage, IC haemorrhage
Hypersensitivity, rash and alopecia
Options for reversing warfarin?
Withholding warfarin, vitamin K, either orally or intravenously, prothrombin complex concentrate(PCC,)(containing factors II, VII, IX & X= 4-factor PCC, without factor VII= 3-factor PCC)
Fresh frozen plasma of PCC unavailable
Often mixture of above= considered- use of PCC/ FFP depends on INR + bleeding severity
What things induce the action of warfarin? Inhibitors? Many what interact with warfarin and should be checked before starting?
Alcohol, allopurinol, paracetamol, SSRIs, lipid-regulating drugs, influenza vaccine
Oral contraceptives and St John’s wort
Antibiotics
For surgeries with a high risk of bleeding, warfarin should be held ideally for how long prior and INR checked when? What can be used to bridge the gap? In severe renal impairment and extremes of weight? Why? When does this bridging take place?
5 days, before/ on the day of surgery
LMWH, UFH- due to its short activity and reversibility in case of bleeding
3 days prior- LMWH= discontinued 1 day prior to procedure and UFH 6 hours
When should INR be checked? When can warfarin be recommenced? Foods high in vitamin K? What can enhance warfarin’s anticoagulant effect?
The day prior to the procedure, once surgical haemostasis has been achieved + oral meds can be tolerated- bridging w/ heparin post-operatively may be required in patients at high risk of TE
Green leafy vegetables, liver, eggs, avocado, olive oil
Cranberry juice
When are blood tests done to monitor warfarin? How should warfarin be taken?
Initially every 3-4 days until 2 consecutive readings are within range, then x2 weekly for 1-2 weeks until 2 consecutive readings are in range
At the same time each day to keep the levels of warfarin steady- if a dose if forgotten, take it as soon as remembered, don’t realise until following day= skip the missed dose
What is arthrotec (diclofenac) contraindicated in? Things to consider appropriate formulation for a child?
Post-stroke
Age and developmental stage of the child, acceptability and palatability, frequency of dosing, ease of administration, convenient and reliable administration, impact on lifestyle, minimum exposure to excipients, whether the formulation can deliver doses variable to age/ weight/ BSA, route of admin needs to be acceptable to the child and their parents/ carers
What advice is given when taking medications alongside colestyramine?
Take them either 1 hour before or 4-6 hours after the colestyramine
How long is morphine’s half life? Remifentanil? Medicines that should be prescribed and administered by brand name?
4-6 hours, minutes
Diltiazem preps, some antiepileptics, lithium salts, theophylline preps, some immunosuppressant therapies e.g. tacrolimus
3 categories of unlicensed preparations of drugs?
1) The medicine is produced and licensed in another country and imported
2) Medicine is unlicensed and produced in a licensed manufacturing unit in this country
3) The medicine is unlicensed and produced in an unlicensed manufacturing facility e.g. such as a pharmacy department
What is a ‘special’? Patient factors to consider when you prescribe a medicine?
An unlicensed preparation of a medicine- liquid or powder versions of a solid oral dosage form specifically intended for patients who have swallowing difficulties, may include topical preparations- not usually on the BNF, contact a pharmacist for advice
The excipients, monitor the patient and note any change in their clinical status
How to take levothyroxine? Simvastatin? How should standard release nitrates be prescribed? Parkinson’s meds?
In the morning before breakfast, at night
So that there is a “nitrate free period” of at least 8 hours - ideally at least 10 hours- prevents the patient developing a tolerance
According to the patient’s usual dosing regimen- late admin can result in ‘end of dose failure’ + return of sx before the next dose
How should timolol standard release eye drops be prescribed and administered?
At 12 hour intervals- failure may result in the glaucoma becoming difficult to control–> sight loss
Only what values can be abbreviated? It is not a legal requirement to do what regarding someone’s DOB? What patient details needed?
Grams and milligrams (g) and (mg)
It isn’t a legal requirement on an inpatient drug chart- legal requirement to include age/ DOB if the patient is under 12 y/o
Full name and address- hospital number in hospital setting, a valid date, my signature, my address, in indelible ink
F1 doctors are not permitted to prescribe what? How to know if they’re controlled? Examples of correct total quantities or number of dosage units?
Controlled drugs
Schedule 2 and 3 preparations= CD2 or CD3 next to them in the BNF- all under “Controlled drugs and drug dependence”
Morphine sulfate MR capsules 10mg BD, supply 14(fourteen capsules)
Morphine sulfate concentrated oral solution 100mg/5ml, 1ml four times a day when required for breakthrough pain, supply 30(thirty) mls
It’s recommended that quantities of controlled drugs don’t exceed what? Meaning of opioid naive? Licensed medicines in the UK have been granted what? This classifies licensed drugs into what 3 classes?
30 days
A patient has not used opioids for more than seven consecutive days during the previous 30 days
General Sales List medicines(GSL)- general sale
Pharmacy Medicines(P)- through pharmacies only
Prescription Only Medicines(POM)- registered practitioners only
Controlled drugs(CD)- registered practitioners only, restrictions on supply apply to some NMPs
What do unlicensed products not have? What is off-label prescribing?
A UK marketing authorisation
The use of a drug that does have a marketing authorisation- its use is outside the terms of its licence- may be at a different dose, indication, or patient group outlined in the ‘Summary of Product Characteristics’(SPC)
If you choose to prescribe multiple routes, check that change in routes does not affect what? What do consider when reviewing prescriptions?
The dose
Review all medication regularly, stop any unnecessary medication, consider documenting review dates, both within the patient’s notes and on the inpatient
How to cancel a prescription on an inpatient drug chart? When amending a dose/ frequency?
Cross through the entire entry, annotate the entry with your signature and a date, do not obliterate it entirely, document any changes in the medical notes- including the rationale
Re-write in full, make an entry in the medical notes
3 stages to medicine reconciliation?
1) Verification- collect info from recent and accurate sources to verify the drug hx
2) Clarification- check this against the current list of medicines prescribed in hospital
3) Reconciliation- document any discrepancies, changes and omissions, whether intentional or unintentional
St John’s Wort can reduce the concentration of what? Garlic, feverfew, Echinacea and ginseng can inhibit what? Common omissions in a drug history? Good mnemonic?
Lansoprazole, platelet aggregation
Borderline substances e.g. vitamins, food supplements, contraceptives, eye/ ear drops, herbal medicines and homeopathic therapies, inhalers, injections, recreational drugs, topical preparations
DRUGS: drugs by registered practitioner, recreational, user- OTC/ complementary, gynaecological, COCP/ HRT, sensitivities- sensitivities and the nature of the reaction
Sources of the drug history?
At least 2 sources of information- ideally the patient and their drugs= primary sources- also GP, carers, community pharmacist, medical notes + electronic prescribing records, NHS Summary Care Record(SCR)
What are warfarin tablets available as?
500 micrograms(white,) 1 mg (brown,) 3 mg (blue,) and 5mg(pink)
How is hydroxocobalamin (vitamin B12) given? Goserelin?
Every 2 or 3 months for maintenance therapy
Monthly/ 3 monthly
What does an upside down black triangle signify? All suspected ADRs to a black triangle must be what?
A medicine is being closely monitored by the Medicines and Healthcare Products Regulatory Agency(MHRA) for adverse effects- all medicines with a new active substance and all new biologics, medicines that require further information after licensing, medicines subject to conditions/ restrictions on safe and effective use
Reported
What is meant by an unlicensed medicine? Off-label?
One that has not been subject to the licensing process- does not have a UK Marketing Authorisation authorised by the MHRA
One that is licensed in the UK, but is being outside the terms of its Marketing Authorisation e.g. one for adults used for a child/ used for an indication not stated in the Marketing Authorisation, administered via a route other than that stated in the licensed way
You must be satisfied of what when prescribing an unlicensed medicine?
There are no suitable licensed alternatives that would meet the patient’s needs, there is sufficient evidence base and/ or experience for using the unlicensed medicine, you must be prepared to take responsbility for prescribing the unlicensed medicine and for overseeing the patient’s care+ monitoring, your decision has been documented in the medical notes including the rationale for the prescription
For renal impairment in children, the eGFR is calculated using what? For a neonate and child over 1 month?
The modified Schwartz equation
30 x height (cm)/serum creatinine (micromol/litre)
35 x height (cm)/serum creatinine (micromol/litre)
Information pertaining to the electrolyte and/ or excipient content of a formulation is listed under what? E.g. of excipients to be aware?
The medicinal forms within a monograph
Alcohols, artificial preservatives/ sweeteners- aspartame/ saccharin, diluents/ vehicles- arachis/ peanut oil, electrolytes- sodium/ potassium, lactose, sensitising agents e.g. beeswax, sorbic acid, parabens
A Yellow Card is submitted for what?
All serious ADRs that result in harm and suspected ADRs to new drugs and vaccines
What is often used to identify patients with an allergy? Type I allergic reactions usually occur within how long of exposure to the triggering drug? Median time to cardiac arrest in fatal drug-induced anaphylaxis? Typical allergic sx?
A red allergy alert band or red identification bracelet
Minutes- 2 hours, 5 minutes
Itching, urticaria, hypotension, angiodema, wheeze
What are fixed drug eruptions? Causes?
Erythematous plaques that recur in the same place each time the causative drug is taken
Paracetamol, tetracyclines and NSAIDs
Prescribe what cautiously when someone has experienced pronounced allergic reactions with penicillins? You can safely prescribe what to patients with a history of penicillin allergy? Advice on individual vaccines and patients for whom they may be contraindicated is kept to date in what?
Cephalosporins and carbapenems
Aztreonam
The “Green book”
Factors that might increase the risk of developing an allergic reaction to a drug?
Atopic individuals: more severe reactions, more likely to react to radiocontrast media
Co-existing conditions: HIV, EBV, CMV and CF= increased risk of drug allergy
Chronic urticaria or mastocytosis- may be sensitive to NSAIDs, opioid analgesics, and other drugs with histamine releasing properties such as atracurium
Drug dependent factors: Beta-lactam antimicrobials, NM blocking agents- NMBAs, radiocontrast media, NSAIDs, high molecular weight starches
Frequent and prolonged doses
Women>men
Topical treatments
What might decrease the risk of allergic drug reactions? Common causes of allergic drug reactions?
Use of low osmolarity agents and pre-dosing with corticosteroids and antihistamines in high risk patients
Chlorhexidine, opioid analgesics, non beta-lactam antimicrobials, NSAIDs, muscle relaxants, opioid analgesics, penicillins and other beta-lactams, plasma expanders, radiocontrast media
Agents that are causes of allergic reactions during anaesthesia? What can aggravate patients with pre-existing urticaria?
Antimicrobials- notably co-amoxiclav & teicoplanin, chlorhexidine, colloids, NM blocking agents, patent blue injection, miscellaneous medicines
NSAIDs and opiates- based on COX-1 enzyme inhibition
In patients with no evidence of systemic reaction, administration of what should be sufficient? What should be available in case of a moderate to severe reaction? Evidence of a severe reaction?
Fast-acting oral antihistamine- chlorphenamine= quick acting and effective H1 antihistamine oral/IV/ IM
IM adrenaline
Hypotension, laryngeal oedema, wheeze, SpO2<92%, impaired consciousness
What should the Sampson severity score(mild–> severe anaphylaxis) be based on? Doses of adrenaline used in adults, children aged 6-12 years old and children younger than 6 years old? Followed by what doses of IV chlorphenamine in adults/>12 y/o, children 6-12 y/o, children 6 months- 6 years, children <6 months old, as well as hydrocortisone?
The organ system most affected
500mcg/ 300 mcg/ 150 mcg
10mg/ 5mg/ 2.5mg/ 250mcg/kg
Doses of hydrocortisone for anaphylaxis in adults/ children>12 y/o, children 6-12 y/o, children 6 months- 6 y/o and children < 6 months y/o?
200mg/ 100mg/ 50mg/ 25mg
Inhaled/ IV what can be used in the management of anaphylaxis? Other examples of bronchodilators? What to prescribe after all moderate to severe anaphylactic reactions to a medicine?
Salbutamol/ ipratropium, aminophylline, magnesium
Prednisolone for up to 3 days, a non-sedating antihistamine for up to 3 days, medical alert band if re-exposure is possible, document the allergy in the medical notes and on the drug chart, communicate to the GP, warn if if in OTC drugs, provide structured written info to the patient, x2 adrenaline auto-injectors for self-administration only significant risk of re-exposure, report–> Yellow card scheme
Refer patients with a drug allergy to a specialist centre for further advice and possible Ix in what following scenarios? Who are adrenaline auto-injectors prescribed for? What is done after every use even if sx are improving? 3 auto-injectors available?
All severe reactions, during/ after general anaesthesia, when future management may be complicated by unnecessary avoidance of the medicine
Those at an increased risk of an idiopathic anaphylactic reaction/ high risk of exposure to anaphylactic triggers e.g. venom stings, food
Ambulance, lie down with legs raised to maintain blood flow, breathing issues- sit up
EpiPen, Emerade, Jext
When should timed blood samples for mast cell tryptase be taken for drug allergies? Observed for how long from the onset of sx if they have received emergency tx and an adult/ child aged 16 y/o or older? When is a mast cell tryptase level helpful and not helpful?
ASAP after emergency tx has started and 1-2 hours after the onset of sx and 24 hours if possible - document drug allergy status separately from ADRs, refer to a specialist allergy service if appropriate
6-12 hours- admit under Paeds if child< 16 y/o
Not if the patient has had the cardinal S&S of an allergic reaction, is in suspected reactions during anaesthesia
Skin prick testing can be done to see if a drug can be administered if what drugs which prevent its effect like what haven’t been recently given? What can give false positives? What’s used to confirm true positive responses?
Antihistamines, H2 receptor antagonists, older antidepressants, systemic corticosteroids, topical corticosteroids
Non-specific histamine release(opiates, NSAIDs, NMBAs) or irritation (e.g. erythromycin)
Intradermal injections at dilutions determined by challenge studies
5 Rs when prescribing IV fluids? Assessment and monitoring of someone’s fluid status?
Resus, routine maintenance, replacement, redistribution and reassessment
Hx: previous limited intake, the quantity and composition of abnormal losses, comorbidities
Exam: pulse, BP, CRT, JVP, pulmonary/ peripheral oedema, presence of postural hypotension
Monitoring: NEWS, fluid balance charts, weight
Lab Ix: FBC, urea, creatinine and electrolytes
Daily reassessments, lab values and fluid balance charts + weight measurement x2 weekly
Signs that someone is hypovolaemic and needs IV fluid resus? If receiving IV fluids for resus, reassess using what and monitor what?
Systolic BP<100mHg, HR>90 bpm, CRT>2 seconds/ peripheries= cold to touch, RR>20 breaths per minute, NEWS= 5 or more, passive leg raising test is positive
The ABCDE approach- RR, pulse, BP and perfusion continuously, venous lactate levels and/ or arterial pH and base excess according to guidance on ALS
If receiving IV fluids w/ chloride concs> 120mmol/l, monitor what? Consider human albumin solution only for resus in who? Adjust to what for obese patients? Consider less fluid for who?
Their serum chloride concentration daily
Patients with severe sepsis
Their ideal body weight
Those with renal impairment or cardiac failure / older or frail/ malnourished and at risk of refeeding syndrome
Consider using what when prescribing for routine maintenance alone? Greater than what risk hyponatraemia?
25-30ml/kg/day NaCl 0.18% in 4% glucose with 27 mmol/l potassium on day 1
2.5 litres
Intracellular fluid has what? Extracellular fluid? EC fluid consists of what? Protein conc is much lower in what compartment? Other force affecting fluid movement between these x2 areas?
High K+ conc, low Na+ conc, intracellular solute concs remain more or less constant
High Na+ conc, low K+ conc- interstitial and intravascular fluid, interstitial fluid
Hydrostatic pressure from circulatory pressures, oedema etc.
Aim for what urine output in fluid replacement? Lost by faeces? Insensible losses? Other?
0.5ml/kg/ hour
100ml/ day, 500-800ml per day
Bleeding, burns
Sweating leads to what? Diarrhoea/ increased stoma output? Vomiting? Insensible losses?
Sodium loss
Sodium, potassium and bicarbonate
Potassium, chloride and hydrogen ions–> hypochloraemic metabolic alkalosis
Pure water loss
Where does isotonic fluid stay? What does hypertonic solutions do? Hypotonic? How does 1000ml NaCl distribute?
Almost entirely within the EC compartment e.g. NaCl 0.9%
Increase plasma tonicity- draw fluid out of cells e.g. NaCl 3%, mannitol
Lower serum osmolarity e.g. NaCl 0.45%
75%–> interstitial compartment, 25%–> intravascular(both EC)
How does 1000ml of glucose 5% distribute?
2/3–> IC fluid, 1/3–> EC fluid, 80ml of EC fluid–> intravascular compartment
How does 1000ml human albumin solution distribute? What are 1st line for fluid resus and maintenance?
1000ml stays in the intravascular compartment
Crystalloids w/ sodium in the range 131-154 mmol/ litre 0.9%
Medical therapies for fluid overload? 4 Ds of fluid therapy?
Stop IV fluids, furosemide- bolus/ infusion, sublingual nitrate, IV nitrate- needs BP monitoring, CPAP
Drug, dose- quantity/ rate, duration- START + review date, de- escalation- when to STOP
Clinical presentation of rhabdomyolysis? RFs? How does diltiazem affect simvastatin?
Muscle swelling, tenderness and weakness, urine= grey-brown due to myoglobin, CK= raised by up to 10-100 times the normal limit
Associated with renal failure- myoglobin precipitates in the renal tubules, also hyperkalaemia as K+ is release when muscle cells break down
Increased age, female, genetic predisposition, pre-existing renal impairment
It inhibits its metabolism by inhibiting the cytochrome P450 isoenzyme CYP3A4- increases toxicity risk
What is an adverse event? ADR?
Any harmful or unpleasant event that patient experiences while using a drug, whether or not it is related to the drug
Adverse event where it is suspected to be cause by the drug
What is a Type A ADR? Type B? C? D? E? F?
Dose-related, common, predictable, related to the pharmacology, unlikely to be fatal e.g. digoxin toxicity/ constipation with opioid analgesics
Not dose-related, uncommon, unpredictable, not related–> pharmacology, often fatal e.g. penicillin hypersensitivity, malignant hyperthermia and hepatitis from anaesthetic agents
Uncommon, related to cumulative dose, time-related
Delayed- uncommon, usually dose-related, occurs/ becomes apparent some time after use of the drug e.g. carcinogenesis
End of tx- uncommon, soon after withdrawal of drug e.g. opiate withdrawal syndrome
3 ADR types according to dose?
Hypersusceptibility- at doses lower than therapeutic, Collateral effects- at therapeutic doses
Toxic effects- at doses higher than those used therapeutically
2 ADR types based on time? Based on time course x6?
Dependent/ independent- any time during the drug tx, may be triggered by something changing drug conc within the body
Rapid reactions, early reactions, first dose reactions, intermediate reactions, late reactions, delayed reactions
Mnemonic for susceptibilities for ADRs?
IGASPED: immunological reactions e.g. allergies, genetics, age, sex, physiology, exogenous- other drugs/ foods/ temperature, disease states affecting the patient
What do neonates have? How does metoclopramide affect children/ young adults and older adults?
Higher body-water content, reduced albumin and total protein, immature BBB
Increased risk of dystonic adverse effects/ Parkinsonism
Conditions that increase the risk of ADRs?
Congestive HF, diabetes mellitus, chronic pulmonary disease, rheumatological and malignant disease
E.g. drugs more common in females> males?
Psych adverse effects with the anti-malarial mefloquine, drug-induced torsade de pointes–> VF + death(women= longer QT interval,) hyponatraemia with diuretics
E.g. of how ethnicity affects drug metabolism?
CYP2C9 allele- more frequently defective in those of European origin, Afro-Caribbean= angioedema with the use of ACE-i, Chinese + Japanese= less psych effects from mefloquine than European/ African origin, increased myopathy risk in Asian origin
Abacavir(antiretroviral) causes severe hypersensitivity reactions mostly in those with what? (Also increased risk of SJS & TEN in use of carbamazepine, phenytoin, oxcarbazepine & lamotrigine)
HLA-B*5701 allele
G6PD causes an increased risk of what? More in who? Risk and severity related to what? Drugs that pose a risk?
Drug-induced haemolytic anaemia- men and Mediterranean, tropical Africa, and Asia
Drug dose and precise gene mutation
Anti-malarials, nitrofurantoin, quinolone antimicrobials, rasburicase, sulphonamides e.g. co-trimoxazole
What is acute porphyria? Patients with this differ how? What is clozapine associated with? How is the risk of blood dyscrasias reduced with methotrexate? Serum- lithium levels taken when?
Inherited disorder of haem biosynthesis- in their responses to medicines
Agranulocytosis(monitor WBCs, platelets and neutrophils)
FBC, renal and LFTs at baseline, weekly until therapy has stabilised and then every 2-3 months thereafter
Every 3 months
4 things needed to submit a vlid report to the Yellow Card scheme? 4 sources for info on ADRs?
Identified patient e.g. hospital number, suspected reactions, suspected drug, reporter
BNF, MHRA, Electronic Medicines Compendium, UK Medicines Information Service
When is ‘red man syndrome’ seen?
When vancomycin is given as bolus injection rather than over at least 60 minutes
How should hypotension be corrected in poisoning? What is common after prolonged coma and aspirin poisoning? HTN associated with what drugs?
Raising the foot of the bed and administration of an infusion of either NaCl or a colloid
Fluid depletion due to vomiting, sweating and hyperpnoea
Sympathomimetic drugs e.g. amphetamines, phencyclidine, and cocaine
How should an obstructed airway in poisoning in the absence of trauma be managed? Consider intubation and ventilation in who? What may be needed? When should O2 be given?
Chin lift or jaw thrust, oropharyngeal/ nasopharyngeal in those with reduced consciousness
Airway can’t be protect/ those with respiratory acidosis
Mouth-to-mouth or bag-valve-mask device
In the highest conc in carbon monoxide poisoning and irritant gases
Cardiac conduction defects and arrhythmias common with the use of what drugs? Hypothermia? Hyperthermia?
Tricyclic antidepressants, some antipsychotics and some antihistamines- seek advice with QT interval prolongation
Those who have been deeply unconscious for some hours- particularly following overdose with barbiturates or phenothiazines- prevent further
CNS stimulants- remove unnecessary clothing and fan, sponging with tepid water
What convulsions don’t require tx? Those that are protracted or recur frequently?
<5 minutes
Lorazepam/ diazepam by slow IV–> large vein/ midazolam oromucosal solution buccally/ diazepam rectally
Tx for methaemoglobinaemia?
Methylthioninium chloride if conc 30% or higher/ sx of tissue hypoxia present despite oxygen therapy
