Adverse Drug Reactions (ADRs) Flashcards
(29 cards)
Define ADR
When does an ADR occur in terms of dosage
Harmful/unwanted effect of a drug
Often display dose response relationship
Many but not all ADRs are produced at doses much higher than the therapeutic dose
Most common adverse effect of statins
muscle pain/weakness that can progress to rhabdomyolysis or death
What statin was withdrawn from the market in 2001
Cerustatin (Baycol)
Side effects of secere adverse muscle reactions and in some cases death
FDA classification of drugs
What weeks are critical in pregnancy & why
3rd and 11th weeks
Increased free drug in plasma
Dangers to foetus before birth
What drugs have teratogenic effects
Isotretinoin
Anti-epileptic drugs
When was thalidomide administered in pregnancy
During 1st trimester for morning sickness
What did thalidomide (now FDA category X) produce
Phocomelia (deletion of long bones of limbs)
What is thalidomide now used as treatment for
Leprosy
Multiple myeloma
What can sodium valproate (used to treat epilepsy and bipolar disorder) during pregnancy result in
Foetal vaproate syndrome (FVS)
Cognitive difficulties
Learning disabilities
Autism
Physical abnormalities
What measures did the MHRA introduce with regard to treatment
- Women must be fully informed of the risks
- Advised on the importance of using effective contraception
- Invited for a yearly review of their treatment
What must drug therapy in the young account for
- GIT absorption (pH and emptying times)
- Plasma binding is reduced in neonates
- Conjugation deficient in some neonates (chloramphenicol)
- All aspects of renal function are reduced at birth
* A number of drugs are absolutely contraindicated while the mother is breast-feeding
Erythematous eruptions
skin rash, most common type of drug-induced skin reaction
Pruritus
may be the first sign of drug hypersensitivity
Urticaria
“hives”, “nettle rash”
Anaphylactic shock
- Life- threatening reaction
- Release of various substances, among which is histamine causing vasodilatation, increased capillary permeability, tissue oedema
- Hypotension, urticaria and erythema of face and neck
- Treat with adrenaline, chlorpheniramine (histamine receptor blocker), corticosteroids (anti-inflammatory drugs)
Aplastic anaemia
Suppression of all bone marrow functions
Agranulocytosis
Complete absence of neutrophils in the blood
Thrombocytopenia
Reduction in platelet count
What are the National Institute for Health and Clinical Excellence (NICE) guidelines for schizophrenia
in individuals with evidence of treatment resistant schizophrenia, clozapine should be introduced at the earliest opportunity
Agranulocytosis incidence rate in patients taking clozapine
When is it highest
1% of patients - highest between 6-18 weeks after commencement
Full blood count should be monitored regularly
Agranulocytosis is an idiosyncratic reaction - difficult to predict
What harmful side effect does thioridazine have (used to treat schizophrenia)
- Prolongs QT interval by blockade of the delayed rectifier cardiac potassium channel (Ik) coded for by HERG
- QT prolongation leads to serious ventricular arrhythmias
- Withdrawn from the market in 2005
What is a side effect of centrally acting drugs
Dizziness
Side effect of aminoglycosides
Tinnitus
