Medical Pharmacology Practice Questions: Anti-Histamine Pharmacology

Choose from the list below the agent exhibiting a relatively long duration of action (12-24 hours).
1. Chlorpheniramine
2. Meclizine
3. Fexofenadine
4. Diphenhydramine
Choose the correct pairs of H1-histamine receptor blockers and their active metabolites available as drugs:
1. Hydroxyzine: cetirizine
2. Terfenadine: fexofenadine
3. Loratadine: Desloratidine
4. A & B
5. B & C
6. A & C
7. A, B & C
Impairment of hepatic metabolism or inhibition of CYP3A4 (cytochrome P450 isoform) can result in cardiac toxicity of which one(s) of the following:
1. Terfenadine
2. Astemizole
3. Both
4. Neither
Characteristic(s) of fexofenadine:
1. As the active metabolite of terfenadine, fexofenadine is also associated with cardiotoxicity..
2. Nonsedating
3. Similar anti-allergic properties noted in the parent drug (terfenadine)
4. A & B
5. B & C
6. A & C
7. A, B & C
Which one() of the following drugs are mainly excreted in the urine?
1. Cetirizine
2. Fexofenadine
3. Loratadine
4. A & B
5. B & C
6. A & C
7. A, B & C
Among the H1-histamine receptor antagonists, this agent administered parenterally effectively suppresses acute dystonic reactions occurring as a result of antipsychotic drug administration.
1. Diphenhydramine
2. Doxylamine
3. Both
4. Neither
Atropine-like consequence(s) of those first-generation H1-receptor antagonists with notable antimuscarinic peripheral activity.
1. Blurred vision
2. Urinary retention
3. Both
4. Neither
Alpha-adrenergic receptor blocking characteristics is associated with numerous H1-histamine receptor blockers.
1. True
2. False
Cyproheptadine is a first-generation H1-histamine receptor antagonist which is also an antagonist at serotonin receptors.
1. True
2. False
Due to sodium-channel blockade properties, some first-generation H1-receptor blockers exhibit local anesthetic actions.
1. True
2. False