Pharmacology Exam: Autacoids

A patient receives diphenhydramine for an allergic reaction but becomes excessively drowsy. What property of this drug most likely causes this side effect?

• Poor oral absorption

• Anticholinergic activity

• High CNS penetration

• Peripheral H1 blockade

Why is loratadine preferred over diphenhydramine for daytime allergic rhinitis?

• Stronger antihistamine effect

• Lower protein binding

• Less sedation due to lower CNS penetration

• Faster onset of action

Which receptor is responsible for the bronchoconstriction observed during anaphylaxis?

• H2

• H1

• 5-HT3

• LT-B4

A physician prescribes famotidine to a patient with GERD. What is the mechanism of action?

• H1 receptor antagonist

• Proton pump inhibitor

• H2 receptor antagonist

• M3 receptor antagonist

Which of the following drugs is a serotonin (5-HT3) receptor antagonist used for chemotherapy-induced nausea?

• Ondansetron

• Sumatriptan

• Cyproheptadine

• Methysergide

Why should aspirin not be given to children with viral infections?

• It inhibits prostaglandins in the CNS

• It causes excessive bleeding

• It increases risk of Reye's syndrome

• It may lead to GI ulcers

A 35-year-old woman uses sumatriptan for migraine. What is its major mechanism of action?

• 5-HT2 receptor blocker

• 5-HT3 receptor antagonist

• 5-HT1B/1D receptor agonist

• Dopamine antagonist

Misoprostol is contraindicated in pregnancy because:

• It causes vasoconstriction of uterine arteries

• It increases gastric acid

• It is a prostaglandin analog that stimulates uterine contractions

• It inhibits COX enzymes

In asthma, which autacoid is most responsible for prolonged bronchoconstriction and mucus secretion?

• Histamine

• Prostaglandin E2

• Bradykinin

• Leukotriene D4

Why are leukotriene receptor antagonists (like montelukast) used in asthma prophylaxis?

• They inhibit phospholipase A2

• They prevent mast cell degranulation

• They block LTC4/D4-mediated bronchoconstriction

• They reduce histamine release