Midterm 1 Drugs

Question 1

Terfenadine

Answer 1

Brand name Seldane
Supposed non-drowsy antihistamine
Metabolized into fexofenadine in the liver (prodrug)
If not metabolized very potent hERG ion channel blocker in the heart
Potentially fatal cardiac arrhythmia (‘torsades de pointes’)

Question 2

Fexofenadine

Answer 2

Produced through metabolism of Terfenadine
Specific non-drowsy antihistamine

Question 3

Benzodiazepines

Answer 3

Positive allosteric modulator for GABA receptors in the brain
Used to alleviate symptoms of alcohol withdrawal

Question 4

Bendroflumethiazide

Answer 4

Block sodium chloride symporter in the distal convoluted tubule
Preventing sodium reabsorption decreases blood volume and blood pressure
Also has direct vasodilatory effect

Question 5

Propranolol

Answer 5

Non-selective beta blocker
Decreases cardiac output in the heart
Causes vasoconstriction of blood vessels in the lungs
Not for patients with asthma (bronchospasm)

Question 6

Atenolol

Answer 6

Selective beta 1 blocker
Decreases cardiac output in the heart

Question 7

Carvedilol

Answer 7

Non-selective beta and alpha blocker
Decreases cardiac output in the heart
Causes vasoconstriction of blood vessels in the lungs
Causes vasodilation of blood vessels in peripheral tissues
Not for patients with asthma (bronchospasm)

Question 8

Prazosin

Answer 8

Selective alpha 1 blocker
Causes vasodilation of blood vessels in peripheral tissues

Question 9

Amlodipine

Answer 9

Calcium Chanel Blocker
Decreases smooth muscle contraction (has vasodilatory effect)

Question 10

Captopril

Answer 10

ACE inhibitor
Prevents ACE from converting ATI to ATII
ATII can’t trigger smooth muscle contraction or aldosterone release
Decrease blood volume and pressure
Side effect is dry cough due to bradykinin pathway

Question 11

Losartan

Answer 11

AT1 Receptor Blocker (ARB)
Prevents smooth muscle contraction and aldosterone synthesis
Decreases blood pressure

Question 12

Spironolactone

Answer 12

Competitive antagonist at the aldosterone receptor
Prevents expression of Na/K pump, ENaC and Na/Cl symporter
Decreases blood pressure

Question 13

Atorvastatin

Answer 13

Commercial name Lipitor
Competitive inhibitor of HMG-CoA reductase
Stops cholesterol synthesis in the liver
Increases expression of LDL receptors on hepatocytes
Decreases circulating LDL

Question 14

Fenofibrate

Answer 14

Agonist of PPAR (peroxisome proliferator-activated receptor)
Activates intracellular receptor to increase expression of lipoprotein lipase
Increases breakdowns of triglycerides in VLDLs and uptake of fatty acids in peripheral tissues
Increases LDL uptake in liver and decreases VLDL production in the liver

Question 15

Acetylsalicylic Acid

Answer 15

Active ingredient in Aspirin
Non-selective NSAID
Irreversible competitive inhibitor of COX1 and COX2 enzymes
Prevents synthesis of PGE2 and TXA2
Analgesic, anti-inflammatory, antipyretic and blood thinning
Side effect of gastric toxicity associated with chronic use

Question 16

Ketoralac

Answer 16

Highly efficacious non-selective NSAID
Chronic use associated with gastric toxicity

Question 17

Celecoxib

Answer 17

Selective NSAID - COX2 inhibitor only
No gastric toxicity
Risk of cardiovascular toxicity

Question 18

Acetaminophen

Answer 18

Weak and reversible COX1 and COX2 inhibitor
Inhibits COX3 (in cerebral cortex)
Analgesic and antipyretic but not anti-inflammatory
In overdose can lead to liver damage and death

Question 19

Procain

Answer 19

Topical anaesthetic
Short half-life due to ester bond in linker region
Blocks sodium ion channels intracellularly
Higher affinity for active neurons

Question 20

Bupivicaine

Answer 20

Topical anaesthetic
Blocks sodium ion channels intracellularly
Higher affinity for active neurons

Question 21

Lidocaine

Answer 21

Topical Anaesthetic
Blocks sodium ion channels intracellularly
Higher affinity for active neurons

Question 22

Capsaicin

Answer 22

Agonist for TRPV1 receptor
Chronic activation of receptor leads to desensitization and analgesia

Question 23

Codeine

Answer 23

Mu opioid receptor agonist
Decreases neuronal signalling in the nucleus tractus solitarus through the Gi signalling cascade
Effective antitussive in low doses

Question 24

Dextromethorphan

Answer 24

Centrally active NMDA receptor antagonist
Inhibits neuronal signalling in the nucleus tractus solitarus
Not very effective antitussive

Question 25

Pseudoephedrine

Answer 25

Non-specific adrenergic receptor agonist Causes vasoconstriction in the nasal mucosa (alpha 1 and 2) Causes vasodilation of bronchial smooth muscles leading to increase mucociliary clearance (beta 2) Can be converted into methamphetamine

Question 26

Phenylephrine

Answer 26

Alpha 1 adrenergic receptor agonist Causes vasoconstriction in the nasal mucosa Less effective than pseudoephedrine

Question 27

Oxymetazoline

Answer 27

Alpha 2 adrenergic receptor agonist Applied directly to nasal mucosa Rhinitis medicamentosa is a risk with prolonged use

Question 28

Guaifenisin

Answer 28

From the bark of the Guaic tree Increases the output of bronchial secretions by decreasing adhesiveness and surface tension

Question 29

Diphenhydramine

Answer 29

Inverse agonist at the H1 receptor Reduces allergy symptoms (block histamine effects) Antitussive properties (active in nucleus tractus solitarus) Drowsy (inversely agonizes CNS H1 receptors in the brain) Can cause dry mouth and constipation (anticholinergic effects)

Question 30

Cetirizine

Answer 30

H1 receptor antagonist Poor blood brain barrier permeability (non-drowsy) No anticholinergic effects

Question 31

Loratadine

Answer 31

Inverse agonist at the H1 receptor Highly bound by albumin (low bioavailability) Converted into Desloratidine by first pass metabolism

Question 32

Magnesium Hydroxide

Answer 32

Antacid with laxative effects

Question 33

Aluminium Hydroxide

Answer 33

Antacids with constipating effects

Question 34

Omeprazole

Answer 34

Proton pump inhibitor Lipophilic weak base Only active in protonated form (pH < 4) Can cause hypergastrinemia

Question 35

Bismuth Subsalicylate

Answer 35

Hydrolyzed in gut into bismuth oxychloride and salicylic acid Bismuth oxychloride has bactericidal effects Salicylic acid inhibits prostaglandin synthesis (anti-inflammatory)

Question 36

Dimenhydrinate

Answer 36

Theoclate salt composed of diphenhydramine and 8-chlorotheophylline Inverse agonist at H1 receptor Slows gut motility Less potent than pure diphenhydramine

Question 37

Loperamide

Answer 37

Mu opioid receptor agonist Slows gut motility Weak analgesic effect P-glycoprotein makes it unable to cross blood brain barrier (unless take in conjunction with amitriptyline)