Pharmacology

Question 1

CYP450 3A4 inhibitors

Answer 1

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Sodium valproate
Isoniazid
Cyclosporin
Ketoconazole
Fluconazole
Alcohol
Clarithromycin (NOT Azithro or Roxithro)
Erythromycin
Ciprofloxacin
Omeprazole
Metronidazole

Question 2

CYP450 3A4 inducers

Answer 2

CRAPGPS

Carbamazepine
Rifampicin
Alcohol
Phenytoin
Groselin
Phenybarbital
Sulphonylureas, St John Wart

Question 3

P-glycoprotein inducers

Answer 3

SCRAPS

Steroids (mainly Dexmethasone)
Cyclosporin (is also a substrate and therefore can induce its own excretion), carbamazepine
Rifampicin
Aspirin
Phenytoin, paclitaxal
St Johns Wort

Question 4

Abs dependent on time dependent Killing

Answer 4

Penicillins
Cephalosporins
Macrolides
Carbapenems
Lincosamides (clindamycin etc)

Question 5

Abs dependent on concentration dependent killing

Answer 5

Aminoglycosides (Gentamicin, Tobramycin, Amikacin)

Question 6

Abs dependent on total exposure

Answer 6

Vancomycin

Question 7

Indapamide MOA

Answer 7

“Thiazide-like diuretic” which blocks NaCl at DCT & also has some action to inhibit peripheral vascular smooth muscle tone

Question 8

Amioloride MOA

Answer 8

Blocks ENaC channels at the collecting duct to work in a similar way to Spironolactone (which indirectly blocks aldosterone to inhibit ENaC). Potassium sparing.

Question 9

Acidic Drugs bind to which plasma protein

Answer 9

Albumin (Phenytoin, Digoxin, Warfarin, NSAIDS, Aspirin, Benzos)
Phenytoin will displace Warfarin and increase free Warfarin causing increased bleeding early - later Phenytoin will induce CYP and increase metabolism of Warfarin and effect

Question 10

Lithium Clearance

Answer 10

100% renally cleared

Question 11

Effect of Urine pH on drug clearance

Answer 11

Acidic drugs i.e Aspirin, Methotrexate, will have increased renal clearance in presence of alkali urine as this ionises the drug insist renal reabsorption. Only non-ionised drugs can cross renal membranes to be reabsorbed.
The opposite occurs for basic drugs

Question 11

Ivabradine MOA

Answer 11

Works at the (I)f Na channels (funny-Na channels) in the pacemaker cells to prolong repolarisation and reduce heart rate, improving symptoms of angina

Question 12

HLA mutation in Han Chinese causing increased allopurinol toxicity

Answer 12

HLAB5801

Question 13

HLA mutation in Han Chinese causing increased carbamazepine toxicity

Answer 13

HLAB1502

Question 14

HLA mutation causing increased hypersensitivity to Abacavir

Answer 14

HLAB5701

Question 15

HLA mutation in Europeans/Japanese causing increased Carbamazepine toxicity

Answer 15

HLAB3101

Question 16

HLA mutation causing increased liver toxicity with Flucloxacillin

Answer 16

HLAB5701

Question 17

CYP required for Tamoxifen metabolism and interaction

Answer 17

CYP2D6 inhibited by SSRI (fluoxetine, Paroxetine) which decreases efficacy

Question 18

CYP involved in Clopdogrel action

Answer 18

CYP2C19 - metabolises clopidogrel (prodrug) to its active form. Decreased CYP219 leads to decreased clopidogrel efficacy. Can occur in presence of inhibitors such as omeprazole.

Question 18

CYP involved in Clopdogrel action

Answer 18

CYP2C19 - metabolises clopidogrel (prodrug) to its active form. Decreased CYP219 leads to decreased clopidogrel efficacy. Can occur in presence of inhibitors such as omeprazole.

Question 19

Diuretic that inhibits renal K secretion at the distal nephron by mineralocorticoid-independent mechanism

Answer 19

Amiloride

Question 20

Albumin bound drugs

Answer 20

Acidic drugs;
Aspirin
NSAIDs
Warfarin
Digoxin
Benzos
Phenytoin

Question 21

CYP 2C9

Answer 21

Metabolises Warfarin
Inhibited by Omeprazole, Amiodarone, Metronidazole, Cimetidine