Comparative Pharmacology
Head-to-head clinical analysis: PROMETHAZINE versus X TROZINE L A.
Peer-Reviewed Evidence
Head-to-head clinical analysis: PROMETHAZINE versus X TROZINE L A.
PROMETHAZINE vs X-TROZINE L.A.
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Promethazine is a phenothiazine derivative that acts as a potent histamine H1 receptor antagonist, thereby blocking the effects of histamine. It also has central anticholinergic, antiemetic, and sedative properties, likely mediated through antagonism at muscarinic, dopamine D2, and serotonin receptors in the brain.
X-TROZINE L.A. is a piperazine derivative that acts as a centrally acting alpha-2 adrenergic agonist, reducing sympathetic outflow from the brainstem, leading to decreased peripheral vascular resistance and lowered blood pressure.
12.5-25 mg IM or IV every 4-6 hours; also 25 mg PO or PR every 6-8 hours. Maximum 100 mg/day.
250 mg orally once daily. May be increased to 500 mg once daily if needed.
None Documented
None Documented
Clinical Note
moderatePromethazine + Risedronic acid
"Promethazine can cause an increase in the absorption of Risedronic acid resulting in an increased serum concentration and potentially a worsening of adverse effects."
Clinical Note
moderatePromethazine + Methylphenidate
"Promethazine can cause an increase in the absorption of Methylphenidate resulting in an increased serum concentration and potentially a worsening of adverse effects."
Clinical Note
moderatePromethazine + Artesunate
"The serum concentration of Artesunate can be increased when it is combined with Promethazine."
Clinical Note
moderateTerminal elimination half-life 9-16 hours; may be prolonged in hepatic impairment.
12-15 hours; prolonged in renal impairment (up to 30 hours in CrCl <30 mL/min).
Renal (70-80% as metabolites, <1% unchanged); biliary/fecal minor.
Primarily renal (70-80% as unchanged drug), with 20-30% fecal via biliary excretion.
Category A/B
Category C
Antihistamine / Antiemetic
Antihistamine
Promethazine + Clotrimazole
"The metabolism of Clotrimazole can be decreased when combined with Promethazine."