Triprolidine hydrochloride is a first‑generation H1 receptor antagonist widely used in management of allergic rhinitis and urticaria. This concise, exam-focused set covers pharmacology, mechanism of action, pharmacokinetics, adverse effects, drug interactions, contraindications and formulation aspects relevant to B.Pharm students. Questions emphasize clinical application, dosing considerations, overdose management, and comparison with second‑generation antihistamines, helping students master mechanisms, safety profiles and therapeutic choices. Detailed MCQs will reinforce learning about CNS effects, anticholinergic reactions, hepatic metabolism and combination products containing triprolidine. Clear answers and explanations support rapid revision for practical exams and pharmacy practice. Now let’s test your knowledge with 30 MCQs on this topic.
Q1. Which pharmacological class does triprolidine hydrochloride belong to?
- Nonsteroidal anti-inflammatory drug
- First‑generation H1 antihistamine
- Second‑generation H1 antihistamine
- Beta‑adrenergic blocker
Correct Answer: First‑generation H1 antihistamine
Q2. What is the primary mechanism of action of triprolidine at the molecular level?
- Selective H2 receptor agonism
- Muscarinic receptor blockade
- Inverse agonist at H1 histamine receptors
- Inhibition of histidine decarboxylase
Correct Answer: Inverse agonist at H1 histamine receptors
Q3. Which clinical indication is triprolidine most commonly used for?
- Hypertension management
- Allergic rhinitis and urticaria
- Bacterial sinusitis
- Asthma maintenance therapy
Correct Answer: Allergic rhinitis and urticaria
Q4. Which central nervous system effect is characteristically seen with triprolidine?
- Marked stimulant effect
- Minimal central effects due to poor BBB penetration
- Significant sedation due to blood–brain barrier crossing
- Selective improvement in cognition
Correct Answer: Significant sedation due to blood–brain barrier crossing
Q5. Which anticholinergic adverse effects are commonly associated with triprolidine?
- Excessive salivation and lacrimation
- Dry mouth and urinary retention
- Bradycardia and hypersalivation
- Increased bowel motility and diarrhea
Correct Answer: Dry mouth and urinary retention
Q6. What is the typical onset of action after oral administration of triprolidine?
- Within 5 minutes
- 15–30 minutes
- 6–8 hours
- 24–48 hours
Correct Answer: 15–30 minutes
Q7. What is the usual duration of action for triprolidine after a single oral dose?
- Less than 1 hour
- 4–6 hours
- 24–36 hours
- 72 hours
Correct Answer: 4–6 hours
Q8. Which statement about triprolidine pharmacokinetics is correct?
- It is exclusively excreted unchanged in feces
- It undergoes hepatic metabolism and renal excretion of metabolites
- It is not absorbed orally and is given only parenterally
- It is stored in adipose tissue with very long half‑life
Correct Answer: It undergoes hepatic metabolism and renal excretion of metabolites
Q9. Which drug interaction is most relevant for triprolidine?
- Potentiation of CNS depression with alcohol and benzodiazepines
- Complete inhibition of warfarin metabolism causing bleeding
- Synergistic antihypertensive effect with ACE inhibitors
- Inactivation by antacids when coadministered
Correct Answer: Potentiation of CNS depression with alcohol and benzodiazepines
Q10. In which patient condition should triprolidine be used with caution or avoided?
- Narrow‑angle glaucoma due to anticholinergic effects
- Hypothyroidism as a first‑line therapy
- Active peptic ulcer as protective therapy
- Type I diabetes mellitus because it lowers blood glucose
Correct Answer: Narrow‑angle glaucoma due to anticholinergic effects
Q11. Which presentation/formulation is triprolidine hydrochloride commonly available in?
- Intravenous continuous infusion only
- Oral tablets and combination cold remedies
- Transdermal patches for chronic use
- Topical ophthalmic suspension only
Correct Answer: Oral tablets and combination cold remedies
Q12. Overdose with triprolidine is most likely to produce which toxidrome?
- Serotonin syndrome
- Anticholinergic toxidrome with delirium and hyperthermia
- Pure cholinergic crisis with sweating and bradycardia
- Opioid overdose with miosis and respiratory depression
Correct Answer: Anticholinergic toxidrome with delirium and hyperthermia
Q13. Which coadministered drug class may have an adverse interaction with triprolidine by increasing anticholinergic effects?
- Acetylcholinesterase inhibitors used in Alzheimer’s disease
- Proton pump inhibitors
- Topical corticosteroids
- Beta‑lactam antibiotics
Correct Answer: Acetylcholinesterase inhibitors used in Alzheimer’s disease
Q14. Compared to second‑generation antihistamines, triprolidine is more likely to:
- Be non‑sedating and highly selective for peripheral H1 receptors
- Cause significant sedation and cross the blood–brain barrier
- Have a longer half‑life and once‑daily dosing advantage
- Exert potent anti‑inflammatory effects on leukotrienes
Correct Answer: Cause significant sedation and cross the blood–brain barrier
Q15. Which physiological effects of histamine are reduced by triprolidine H1 blockade?
- HCl secretion from gastric parietal cells (H2 mediated)
- Vasodilation and increased vascular permeability
- Beta‑adrenergic mediated bronchodilation
- Alpha‑adrenergic vasoconstriction
Correct Answer: Vasodilation and increased vascular permeability
Q16. Which patient population is at higher risk of adverse effects from triprolidine and requires dose caution?
- Young adults aged 20–30 years
- Elderly patients due to increased sensitivity to sedation and anticholinergic effects
- Patients with well controlled asthma only
- Patients with hyperthyroidism who require higher doses
Correct Answer: Elderly patients due to increased sensitivity to sedation and anticholinergic effects
Q17. Which symptom might paradoxically occur in children after taking triprolidine?
- Profound somnolence without agitation
- Paradoxical excitation and hyperactivity
- Permanent hearing loss
- Rapid weight gain
Correct Answer: Paradoxical excitation and hyperactivity
Q18. Triprolidine hydrochloride is often combined with which decongestant in OTC cold preparations?
- Pseudoephedrine
- Amoxicillin
- Salbutamol
- Ibuprofen
Correct Answer: Pseudoephedrine
Q19. Regarding storage, how should triprolidine tablets typically be stored in a community pharmacy?
- Frozen at −20 °C
- At room temperature, protected from light and moisture
- In direct sunlight to preserve potency
- In highly humid conditions
Correct Answer: At room temperature, protected from light and moisture
Q20. The hydrochloride salt form of triprolidine primarily provides which pharmaceutical advantage?
- Increased lipid solubility for better brain uptake
- Improved water solubility and stability for oral formulation
- A long‑acting depot effect after intramuscular injection
- Selective binding to H2 receptors
Correct Answer: Improved water solubility and stability for oral formulation
Q21. Which intracellular signaling pathway is directly associated with H1 receptor activation that triprolidine blocks?
- Gs protein activation increasing cAMP
- Gi inhibition of adenylate cyclase
- Gq activation increasing IP3 and DAG signaling
- Toll‑like receptor mediated NF‑κB activation
Correct Answer: Gq activation increasing IP3 and DAG signaling
Q22. In suspected recent oral overdose of triprolidine, which immediate management step is appropriate?
- Administer activated charcoal if within the appropriate time window
- Perform immediate hemodialysis as first‑line
- Give high‑dose naloxone
- Induce vomiting at home
Correct Answer: Administer activated charcoal if within the appropriate time window
Q23. Triprolidine produces therapeutic relief in allergic symptoms primarily by blocking histamine effects on which target tissue?
- Gastric parietal cells only
- Peripheral blood vessels and sensory nerve endings
- Pancreatic islet cells
- Cardiac pacemaker cells exclusively
Correct Answer: Peripheral blood vessels and sensory nerve endings
Q24. Which monitoring parameters are most relevant for a patient starting triprolidine therapy?
- Monitoring for sedation, urinary retention and vision disturbances
- Regular INR checks like with warfarin therapy
- Frequent blood glucose monitoring only
- Continuous ECG monitoring for all patients
Correct Answer: Monitoring for sedation, urinary retention and vision disturbances
Q25. Which statement best describes oral bioavailability of triprolidine?
- Poorly absorbed with negligible systemic availability
- Well absorbed orally but subject to first‑pass hepatic metabolism
- Completely destroyed in the stomach acid and inactive
- Only effective if administered subcutaneously
Correct Answer: Well absorbed orally but subject to first‑pass hepatic metabolism
Q26. Which of the following is a common rationale for preferring a second‑generation antihistamine over triprolidine in chronic allergic rhinitis?
- Second‑generation agents cause more anticholinergic symptoms
- Second‑generation agents have less sedation and better tolerability
- Triprolidine is more selective for peripheral H1 receptors
- Second‑generation agents require frequent dosing every 3–4 hours
Correct Answer: Second‑generation agents have less sedation and better tolerability
Q27. Which cardiovascular effect can be seen with anticholinergic properties of triprolidine?
- Marked bradycardia in all patients
- Tachycardia due to vagal inhibition
- Immediate hypotension via alpha blockade
- Direct myocardial necrosis
Correct Answer: Tachycardia due to vagal inhibition
Q28. Which of the following is a pharmacodynamic consequence when triprolidine is coadministered with opioid analgesics?
- Reduced CNS depression compared with either drug alone
- Potentiation of CNS depressant effects leading to increased sedation
- Complete antagonism of opioid analgesia
- Enhanced diuretic effect
Correct Answer: Potentiation of CNS depressant effects leading to increased sedation
Q29. Does triprolidine cross the placenta, and what is the significance for pregnant patients?
- It does not cross the placenta and is completely safe in pregnancy
- It crosses the placenta; use requires risk–benefit assessment in pregnancy
- It is actively transported out of the fetal circulation and accumulates in placenta
- It causes teratogenesis in all trimesters and is absolutely contraindicated
Correct Answer: It crosses the placenta; use requires risk–benefit assessment in pregnancy
Q30. Which receptor subtype is the direct pharmacological target of triprolidine?
- H2 histamine receptor
- H3 histamine receptor
- H1 histamine receptor
- Beta‑2 adrenergic receptor
Correct Answer: H1 histamine receptor
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