Comparative Pharmacology
Head-to-head clinical analysis: PHERAZINE VC W CODEINE versus QDOLO.
Peer-Reviewed Evidence
Head-to-head clinical analysis: PHERAZINE VC W CODEINE versus QDOLO.
PHERAZINE VC W/ CODEINE vs QDOLO
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Codeine: Opioid receptor agonist (mu-receptor), suppresses cough reflex. Phenylephrine: Alpha-1 adrenergic receptor agonist, vasoconstrictor. Promethazine: Histamine H1 receptor antagonist, anticholinergic, antiemetic.
Tramadol is a centrally acting synthetic opioid analgesic. It binds to μ-opioid receptors and inhibits norepinephrine and serotonin reuptake.
Adults: 5 mL (one teaspoonful) orally every 4 to 6 hours as needed; each 5 mL contains promethazine hydrochloride 5 mg, phenylephrine hydrochloride 5 mg, and codeine phosphate 10 mg. Maximum daily dose: codeine 120 mg (6 doses).
Oral: 50-100 mg every 4-6 hours as needed for pain; maximum 400 mg per day. Immediate-release tablets only. Extended-release formulations require different dosing and are not interchangeable.
None Documented
None Documented
Codeine: 2.5-3.5 hours (terminal); phenylephrine: 2-3 hours; promethazine: 10-19 hours (clinical context: prolonged in renal impairment, accumulation with chronic use).
Terminal elimination half-life approximately 2-4 hours in adults; prolonged to 4-6 hours in elderly and up to 12-16 hours in severe renal impairment (CrCl <30 mL/min)
Renal: codeine (40-70% as free and conjugated metabolites, including morphine, norcodeine, and hydromorphone); phenylephrine (80-90% as conjugated metabolites, 10% unchanged); promethazine (primarily as sulfoxides and glucuronides, renal elimination about 70%). Fecal/biliary: minor.
Renal 90% (60% unchanged, 30% as glucuronide conjugate), fecal 10%
Category D/X
Category C
Opioid Agonist
Opioid Agonist