Drugs And Actions

Question 1

*Atropine

Answer 1

**nonselective muscarinic antagonist **
blocks Ach peripheral and centrally.
cardiovascular –> M2–> cAMP increases–> contraction and CO
–> Emergencies in surgery to increase heart rate/before GA

dry mouth, constipation, headaches

increase hypertension
increase or decrease anti collinergic effects

Question 2

Benzatropine

Answer 2

M1 muscarinic antagonist
Inhibits ach –> inhibits dopamine reuptake
= Parkinson

dry mouth, constipation, headaches

increase hypertension
increase or decrease anti collinergic effects

Question 3

*Perindopril

Answer 3

ACE inhibitor
prevent conversion AGTI –>AGTII (vasocontriction)
=Hypertension / heart failure

cough, dizziness, postural HYPOtension

triple whammy + diuretic + NSAIDs –> renal failure

Question 4

*Losartan

Answer 4

ARB
specific to smooth muscle wall = Angiotensin receptor blocker
Vasodilation
=hypertension

Xerostomia, dizziness, postural HYPOtension

triple whammy + diuretic + NSAIDs –> renal failure

Question 5

*Frusemide

Answer 5

loop diuretic
inhibits cotransporter NA-K-CL –> inhibits Na, Cl, K reabsorption = more urine excreted
= hypertension –>decrease blood (plasma) volume
= heart failure

Xerostomia, dehyration, Postural hypotension

triple whammy + diuretic + NSAIDs –> renal failure

Question 6

*Indapamide

Answer 6

Thiazide diuretic
Inhibits Na+ & Cl- retuptake in the distal tubule, reduced osmotic pressure, increasing urinary output, Lowering blood volume = lower Cardiac output (CO)
=Hypertension

Xerostomia, dehydration

triple whammy + diuretic + NSAIDs –> renal failure

Question 7

Spironolactone

Answer 7

K sparing diuretic
Antagonizes aldosterone at the distal tubule
A weak diuretic: inhibit Na+ reuptake, hence makes the kidney pass out more fluid whilst retaining/increasing potassium by inhibiting the exchange between Na and K
=MAnagement of odema from heartfailure
weak –> hypertension

Hyperkalemia, Xerostomia, dehydration, menstrual abnormalities

triple whammy + diuretic + NSAIDs –> renal failure

Question 8

*Amlodipine

Answer 8

Calcium channel blocker
. Vascular smooth muscle selective = dihydropyridines
Vasodilator
=hypertension

Gingival hyperplasia, xerostomia, dizziness, taste disturbances

CYP interaction
(erytheromycin or miconazole-treats thrush)

Question 9

Darifenacin

Answer 9

Anti muscarinic antagonist
M3: Smooth muscle (bladder)
relaxes detruser muscle of the bladder
=*urinary incontenance *

Xerostomis, constipation, headaches, tachycardia

Question 10

*Atenolol

Answer 10

B1 antagonist (B blockers)
Prevents NE/E from binding to B-adrenergic receptors in SA node
Decrease contraction (-ve inotropic effects),
decreased HR (-ve chronotropic effects)
decrease SV= decrease CO = decrease BP
=hypertension

fatigue, postural hypotension, dizziness

cardiac depression with GA, NSAIDS = antagonist to B blockers,

Question 11

Digoxin

Answer 11

NA/K ATPase
ATPase = controls movement of Ca, Na and K in heart. Increase intracellular Ca and Na Increase cardiac contractility > increase cardiac output
Increase strength/efficiency heart contractions
=Heart failure, AF

Weakness, dizziness, SOB, nausea, vomiting

Verapamil = toxicity due to heapatic metabolism

Question 12

*Glyceryl Trinitrate (GTN)

Answer 12

Nitrate
stimulates guanylate cyclase in smooth muscles by decreasing Ca and vascular tone > venodilation
Reduction in CO and arterial pressure reduces the O2 demand by the myocardium + dilation of coronary and coronary collateral vessels increases coronary perfusion and oxygen delivery
=Angina

Xerostomia, Dizziness, Syncope, headaches, postural hypotension

PDE5 inhibitors (e.g. Sildenafil-excessive hypotension)

Question 13

Amiodarone

Answer 13

K inhibitor = Anti-arrhythmic
* Blocks certain electrical signals in the heart
* Can block K, Na, C and B receptors. Has the potential to cause a variety of complex effects in the heart
* =Ventricular fibrillation, Tachycardia

Metallic taste, skin rash, pulmonary fibrosis, GI and CNS disturbances

CYP interaction
(erytheromycin or miconazole-treats thrush)

Digoxin: CYP interactions

Question 14

Flecainide

Answer 14

Na inhibitor = Anti-arrhythmic
Suppresses premature ventricular contractions
* QT elongation
* = ventricular tachycardia, AF, dysrhythmias*

Xerostomia

Question 15

*Diltiazem

Answer 15

non-dihydropyradines = Cardiac specific
Calcium channel blockers
reduce HR and cardiac contractility
* =Arrythmias

Gingival hyperplasia Orthostatic Hypotension DizzinessTaste disturba

Question 16

*Atorvastatin

Answer 16

HMG-CoA reductase inhibitor
inhibits synthesis of cholesteroal through liver enzyme HMG-CoA reductase –> reduce LDL’s
Lowers LDL and TG and raise HDL
* Dyslipidaemia

Dizziness

CYP interaction
(erytheromycin or miconazole-treats thrush)

Question 17

*Fenofibrate

Answer 17

PPAR-alpha agonist
Increase lipolysis; decrease TG
Lowers TG, LDL and raise HDL
* severe hypertriglyceridemia
* mixed hyperlipidaemia

Dizziness, nausea, constipation

Question 18

*Aspirin

Answer 18

Anti platelet Thromboxane synthesis inhibitor
Blocks COX-1 = thromboxane A2 (aggregatior).
Prevent platelet aggregation
Blocks COX-2: prostaglandins (promote pain, inflammation, fever, also cause platelets to stick together and form a blood clot, protection of stomach from acid
* = Thromboembolism, Heart attack, stroke, pain, inflammation

GI issues (pain ulcerations), KI/LR failure, bleeding

Warfarin (stomach bleeding)
Anti-thrombotics (bleeding risk)
SSRIs & NSAIDS (bleeding risk)
Antihypertensives (increase BP- physiological antagonists)
Diuretics (reduce effect)

Question 19

*Clopidogrel

Answer 19

Anti-platelet
P2Y12 inhibitor
Prevents platelet aggregation/thromboxane production
Decreased clots formed = stroke & Heart attack

Taste disturbance

Grape juice: can increase side effects

Question 20

*Dabigatran

Answer 20

Anti Coagulant
Blocks cleavage of fibrinogen (I) into fibrin (Ia); activation of platelets, and clot formation
= DVT, stroke

Bleeding from gums

Antiplatelet
NSAIDs

Question 21

*Warfarin

Answer 21

Anti Coagulant
Vitamin K antagonist
=Myocardial infarction
Pulmonary embolism
Strokes
Atrial fibrillation
Venous thrombosis
Thromboembolism

Dizziness, headache, weakness, bleeding gums

Increased bleeding risk:
Anti-coagulants
Direct thrombin inhibitors
Antiplatelets
NSAIDs
SSRI’s (e.g. sertraline)
Antibiotics (e.g. erythromycin)
Antifungals (e.g. miconazole)
CYP450 enzyme drugs (e.g. amiodarone, erythromycin, miconazole, metronidazole)

Question 22

*Enoxaparin

Answer 22

Anti Coagulant
Inhibits factor Xfactors Xa and IIa. Factor Xa catalyzes the conversion of prothrombin to thrombin
=Stroke, DVT

Nausea, Diarrhoea, fever

NSAIDs
Anticoagulants

Question 23

*Rivaroxaban

Answer 23

Anti Coagulant

Inhibits free and clot bound factor Xa- needed to activate prothrombin (factor II) to thrombin (factor IIa).
One molecule of factor Xa can generate more than 1000 molecules of thrombin
The action is irreversible

Bleeding gums, Dizziness, Headache, Coughing up blood

Antiplatelet
NSAIDs

Question 24

*Tranexamic acid

Answer 24

Anti-fibrinolytic
Inhibits activation of plasminogen

= Reduce/prevent hemorrhage during and following tooth extraction
=Haemophilia (short term use- 2-8 days)

Hoarseness, Swelling of face
Difficulty breathing/swallowing
Caution in

Question 25

*Aluminium chloride

Answer 25

**Clot Formation = Haemostasis ** precipitates blood proteins = *superficial and local coagulation in minor hemorrhages - dental procedures*

Question 26

*Ferric sulphate

Answer 26

Iron deficiency anemia | Sore throat, trouble swallowing, severe stomach pains ## Footnote Antibiotics

Question 27

*Ibuprofen

Answer 27

NSAID Anti-pyrectic Anti inflam Analgesic | Asthma Bleeding Hypertension GI issues Renal failure ## Footnote Anti-coagulants ACE ARBS Anti hypertensives Lithium

Question 28

*paracetamol

Answer 28

Cox inhibiotor Anti pyretic / Analgesic *not anti inflam* cyclo-oxiginase pathway reduce PG synthesis | Hypersensitivity Skin rash Hepatic/renal function easy to overdose ## Footnote Anticoagulant warfarin

Question 29

*Tramadol

Answer 29

* Centrally acting opiate agonist * Weak mu agonist * Noradrenalin reuptake inhibitor * Serotonin reuptake inhibitor | Dry mouth, Respiratory depression Constipation Nausea ## Footnote SSRI’s = serotonin syndrome Alcohol Benzodiazepines CYP2D6 interactions Sedatives Anti histamines

Question 30

*Codeine

Answer 30

Pro drug mu opioid agonist = Pain management activated by CYP2D6 --> converted to morphine Nausea Constipation hypotension metabolising ability = effect | Sedation ## Footnote CYP2D6 interactions sedatives TCA Anti histamines

Question 31

*Oxycodone

Answer 31

Strong Mu agonist Pain management * often combines with Naloxone for constipation | Sedation Nausea Constipation ## Footnote CYP2D6 interactions CNS depressants

Question 32

Hydrocortisone

Answer 32

Glucocorticoid ↓immune function Reduce inflammation, ↓vascular permeability and pain | Topically = taste disturbance, C. Albicans overgrowth Caries risk skin ## Footnote Withdrawal with long term use (7.5g 3 weeks) Live attenuated VACCINES Rivampacin

Question 33

*Esomeprazole

Answer 33

PPI GORD Healing gastric ulcer | Decreased gastric activity Vitamin B12 deficiency ## Footnote Clopidogrel CYP2C19

Question 34

* Phenoxymethylpenicillin

Answer 34

**Penicillin** bacteriacidal narrow spectrum, gram +ve | GI upset ## Footnote Caution with breastfeeding **Aminoglycosides** **Anti-coagulants**

Question 35

*Amoxicillin

Answer 35

**Penicillin** Inhibits Peptidoglycan synthesis bacterioscidal extended spectrum both gram =ve/-ve Penicillin sensitivity, caution with brestfeeding | GI upset ## Footnote Caution with breastfeeding **Aminoglycosides** **Anti-coagulants**

Question 36

*Clindamycin

Answer 36

**Lincosamides** Binds 50s ribosomal subunit Inhibits protein synthesis = Bacteriostatic, gram +ve has a cross sensitivity to Macrolides often used for penicillin allergy used in dentisty b/c soft tissue and bone infections Anaerobes | Pseudomembranous colitis ## Footnote **Erythromycin **CYP3A4/ 3A5 inhibitors strong 3A4 inducers rifampicin, nephrotoxics

Question 37

*Metronidazole

Answer 37

Nitroimidazole = anaerobic Binds DNA Inhibits protein synthesis = bacteriostatic | Furry black tongue Candida Overgrowth Confusion, dizziness GIT symptoms ## Footnote **Alcohol** --> anti abuse: flushing, tachycardia **Warfarin** QT elongation

Question 38

*Doxycycline

Answer 38

**tetracyclines** Inhibit protein synthesis = Bacteriostatic broad spectrum * has a stat dose of 200mg due to lomg half life | Tooth discolouration Slows bone growth Epigastric burning photosensitivi ## Footnote Chelation interactions Magnesium, Calcium, iron, antacids

Question 39

Ciprofloxacin

Answer 39

**fluoroquinolone antibiotic** Inhibits topoisomerase 2 & 4 Gram -ve Affects tendons (elderly, neonates)

Question 40

Acyclovir

Answer 40

Inhibits DNA polymerase --> unable to replicate and infect other cells 200mg 4 hourly Antiviral Herpes virus | - Irritant to mucousa topically ## Footnote Drugs that compete with renal clearance-cimetidine

Question 41

Miconazole 1% cream

Answer 41

Anti-fungal Azoles 14 α sterol demethylase = a CYP 3A enzyme Impairs cell membrane synthesis and replication/infection of other cells | Hepatoxicity Hypersensitivity Skin burning, ## Footnote CYP interactions even topically Warfarin Anti coagulants

Question 42

Amphotericin (10mg lozenge – 4 x day 7-14 days)

Answer 42

**Anti Fungal = thrush** Ergasterol binding cell membrane --> Alter membrane permeability and creates K+ pores | Hypersensitivity Mild GI symptoms

Question 43

Nystatin 1ml 4 x day

Answer 43

Anti Fungal = Thrush Ergasterol binding cell membrane | Hypersensitivity

Question 44

What are CYP450 drugs

Answer 44

amiodarone erythromycin miconazole metronidazole

Question 45

What has CYP interactions

Answer 45

Erythromycin Miconazole

Question 46

What does child-Pugh score measure

Answer 46

Liver function * albumin * bilirubin * acites * hepatic encephalopathy *INR

Question 47

Spreading odontogenic infection No systemic symptoms

Answer 47

Metronidazole 400mg 12 hourly 5 days + Amoxicillin OR phenooxymethlypeni 500mg 8 hourly 5 days

Question 48

Spreading odontogenic infection WITH penicillin allergy

Answer 48

Metronidazole 400mg 12 hr 5 days + Clindamycin 300mg 8 hours 5 days

Question 49

Efficacy

Answer 49

Ability of a drug to create a cellular response

Question 50

Intrinsic efficacy

Answer 50

The ability of a drug to activate a protein

Question 51

Affinity

Answer 51

Shown by rate drug dissociates from receptor

Question 52

Potency

Answer 52

Concentration of a drug required to produce an effect * low amount creates an effect = high potency

Question 53

Full agonist

Answer 53

100% response rate

Question 54

Partial agonist

Answer 54

Less than 100% response Regardless of how much drug is administered —> low intrinsic efficacy

Question 55

Agonist

Answer 55

Binds with drug but DOES NOT make confirmational change

Question 56

Inverse agonist

Answer 56

Drug that causes conformational change in receptor - makes inactive - stabilise receptor inactive form - response doesn’t begin at zero goes down on graph

Question 57

Factors effecting bioavailability

Answer 57

Passive diffusion- partition coefficient, hydrophobicity Molecular weight Active transport/facilitated transport Ionisation and pka Pore mediated transport Modifying - antacids -food - fats Nitroglycerin - given sublingually liver Lignocaine = first pass effect very high, given injection

Question 58

Orthostatic hypotension

Answer 58

CCB - diltiazem Loop diuretics - frusemide, indapamide Nitrates - GTN Arbs- losartan B antagonist - bisoprolol

Question 59

Dizziness

Answer 59

Arb Ace cCB B blocker HMG pPAR

Question 60

Taste disturbance

Answer 60

Irbesartan Amlodipine Clopidogrel Metallic = amiodarone

Question 61

Gingival hyperplasia

Answer 61

Amlodopine THE MOST Diltiazem Verapamil

Question 62

Angioedema

Answer 62

Ace - perindopril