Mechanism of action quiz

ACE inhibitors · Lisinopril: Inhibits angiotensin-converting enzyme, blocking conversion of angiotensin I to angiotensin II and suppressing the renin-angiotensin-aldosterone system.

Angiotensin II receptor blockers · Losartan: Losartan and its active metabolite block the vasoconstrictor and aldosterone-secreting effects of angiotensin II at its receptor.

Beta-adrenergic blockers · Metoprolol: Beta-1 selective (cardioselective) adrenergic receptor blocker without intrinsic sympathomimetic activity; blocks beta-2 at higher levels.

Dihydropyridine calcium channel blockers · Amlodipine: Dihydropyridine calcium antagonist that inhibits transmembrane influx of calcium ions into vascular smooth muscle and cardiac muscle.

HMG-CoA reductase inhibitors · Atorvastatin: Selectively and competitively inhibits HMG-CoA reductase, a key enzyme in cholesterol synthesis. In animal models, increased hepatic LDL receptors also contribute to LDL uptake and breakdown.

Proton pump inhibitors · Omeprazole: Substituted benzimidazole that inhibits the H+/K+ ATPase (proton pump) of the gastric parietal cell, blocking the final step of acid secretion.

Selective serotonin reuptake inhibitors · Sertraline: Potentiates serotonergic activity in the CNS by inhibiting neuronal reuptake of serotonin (5-HT).

Serotonin-norepinephrine reuptake inhibitors · Duloxetine: Exact mechanism unknown; believed to potentiate serotonergic and noradrenergic activity in the CNS.

Benzodiazepines · Alprazolam: Binds the benzodiazepine site of GABA-A receptors, enhancing GABA-mediated synaptic inhibition.

SGLT2 inhibitors · Empagliflozin: Inhibits renal SGLT2, reducing glucose reabsorption and increasing urinary glucose excretion; also reduces sodium reabsorption and increases sodium delivery to the distal tubule.

DPP-4 inhibitors · Sitagliptin: A DPP-4 inhibitor believed to act by slowing incretin inactivation. It increases and prolongs active GLP-1 and GIP levels, which influence insulin and glucagon in a glucose-dependent manner.

GLP-1 receptor agonists · Semaglutide: GLP-1 analogue that selectively binds and activates the GLP-1 receptor; albumin binding gives it a long half-life.

Insulins · Insulin glargine: Regulates glucose metabolism: stimulates peripheral glucose uptake (muscle, fat) and inhibits hepatic glucose production.

5-HT1B/1D receptor agonists · Sumatriptan: Presumed to act in migraine through 5-HT1B/1D agonism on intracranial vessels and trigeminal sensory nerves, producing cranial vasoconstriction and reduced pro-inflammatory neuropeptide release.

Direct factor Xa inhibitors · Apixaban: Selective inhibitor of free and clot-bound factor Xa and prothrombinase, independent of antithrombin III; decreases thrombin generation.

Nonsteroidal anti-inflammatory drugs · Ibuprofen: Has analgesic, antipyretic and anti-inflammatory effects. The selected label says the mechanism is not fully understood and may involve inhibition of prostaglandin synthesis.

Fluoroquinolone antibacterials · Ciprofloxacin: Inhibits bacterial DNA gyrase (topoisomerase II) and topoisomerase IV, disrupting processes required for bacterial DNA replication and maintenance.

Penicillin antibacterials · Amoxicillin: Interferes with bacterial cell-wall formation, killing susceptible organisms while they are actively multiplying.

Cephalosporin antibacterials · Cephalexin: Disrupts bacterial cell-wall synthesis, producing a bactericidal effect against susceptible organisms.

Macrolide antibacterials · Azithromycin: Binds to the bacterial 50S ribosomal subunit and interrupts protein synthesis.

Loop diuretics · Furosemide: Inhibits sodium and chloride reabsorption in the loop of Henle and the proximal and distal tubules.

Thiazide and thiazide-like diuretics · Hydrochlorothiazide: Affects distal renal tubular electrolyte reabsorption and increases sodium and chloride excretion. The selected label describes the mechanism of its antihypertensive effect as unknown.

Opioid analgesics · Oxycodone: A full opioid agonist with relative mu-receptor selectivity and analgesic activity. Although there is no defined ceiling for analgesia, respiratory and CNS adverse effects limit dosing.

Antimuscarinic bladder medicines · Oxybutynin: Relaxes bladder smooth muscle by a direct antispasmodic effect and by inhibiting the muscarinic action of acetylcholine.

Alpha-1 adrenergic blockers · Tamsulosin: Blocks alpha-1 adrenoceptors with selectivity for receptors in the human prostate. Relaxation of prostate and bladder-neck smooth muscle improves urine flow and BPH symptoms.

P2Y12 platelet inhibitors · Clopidogrel: Prodrug; active metabolite irreversibly binds P2Y12 ADP receptors on platelets, inhibiting platelet activation and aggregation.

5-alpha reductase inhibitors · Finasteride: Competitive, specific inhibitor of type II 5-alpha reductase, blocking conversion of testosterone to DHT.

Dopamine receptor agonists · Ropinirole: Non-ergoline dopamine agonist thought to act by stimulating D2 receptors in the caudate-putamen.