Comparative Pharmacology
Head-to-head clinical analysis: FAYOSIM versus PROMETHAZINE W CODEINE.
Peer-Reviewed Evidence
Head-to-head clinical analysis: FAYOSIM versus PROMETHAZINE W CODEINE.
FAYOSIM vs PROMETHAZINE W/ CODEINE
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
FAYOSIM (plecanatide) is a guanylate cyclase-C (GC-C) agonist. It binds to GC-C receptors on the luminal surface of intestinal epithelial cells, activating the receptor and increasing intracellular cyclic guanosine monophosphate (cGMP) levels. Elevated cGMP stimulates chloride and bicarbonate secretion into the intestinal lumen, enhancing fluid secretion and accelerating gastrointestinal transit, thereby promoting bowel movements.
Codeine is a prodrug converted to morphine, a mu-opioid receptor agonist, which inhibits nociceptive transmission; promethazine is a phenothiazine derivative with H1-receptor antagonism, anticholinergic, and antiemetic effects.
10 mg orally once daily
10 mL (1 mg codeine, 6.25 mg promethazine per 5 mL) orally every 4-6 hours as needed for cough. Maximum: 60 mL per day. Do not exceed 5 days.
None Documented
None Documented
12-16 hours in healthy adults; prolonged to 20-30 hours in moderate renal impairment (CrCl <50 mL/min) requiring dose adjustment.
Promethazine: 10-19 hours (terminal). Codeine: 2.5-3.5 hours (terminal); prolonged in renal impairment.
Primarily renal elimination, 80% unchanged drug in urine; 15% biliary/fecal; 5% metabolized.
Promethazine: renal (70% as metabolites, <1% unchanged), fecal (20-30%). Codeine: renal (90%, of which 5-10% unchanged, rest as metabolites), fecal (minor).
Category C
Category A/B
Antihistamine
Antihistamine / Antiemetic