Comparative Pharmacology
Head-to-head clinical analysis: EPINASTINE HYDROCHLORIDE versus PBZ.
Peer-Reviewed Evidence
Head-to-head clinical analysis: EPINASTINE HYDROCHLORIDE versus PBZ.
EPINASTINE HYDROCHLORIDE vs PBZ
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Selective histamine H1-receptor antagonist. Inhibits histamine release from mast cells and basophils, and reduces chemotaxis and activation of eosinophils. Also suppresses cytokine production from T lymphocytes.
PBZ (phenylbutazone) is a nonsteroidal anti-inflammatory drug (NSAID) that inhibits cyclooxygenase (COX) enzymes, reducing prostaglandin synthesis. It also has uricosuric effects.
For allergic rhinitis and urticaria: 10 mg twice daily orally (20 mg/day). For ophthalmic use: 1 drop in affected eye(s) twice daily of 0.05% solution.
25-50 mg orally every 4-6 hours as needed; not to exceed 300 mg/day. For severe allergies: 25 mg intramuscularly or intravenously every 4-6 hours.
None Documented
None Documented
The terminal elimination half-life is approximately 5.7 to 9.2 hours in healthy adults. In elderly patients, the half-life may be prolonged due to reduced renal function. The half-life supports twice-daily dosing for most indications.
Terminal elimination half-life: 8-12 hours in adults; prolonged in renal impairment (up to 24 hours).
Renal excretion accounts for approximately 39% of the administered dose, with about 28% as unchanged drug and 11% as metabolites. Fecal excretion is minimal at approximately 10%. Biliary excretion is not a significant route. Overall, renal clearance is the primary elimination pathway.
Renal excretion of unchanged drug (approximately 70-80%) with the remainder as metabolites. Biliary/fecal excretion accounts for <5%.
Category A/B
Category C
Antihistamine
Antihistamine