Codeine
Medicinal Chemistry
Molecular Weight
299.36
Molecular Formula
C18H21NO3
IUPAC Name
(5alpha,6alpha)-7,8-didehydro-4,5-epoxy-3-methoxy-17-methylmorphinan-6-ol
Pharmacognosy
Biological Source
Papaver somniferum
Active Constituents
Codeine
Pharmacology & Synthesis
Mechanism of Action
Weak agonist at mu-opioid receptors; suppresses medullary cough center.
Pharmacokinetics (ADME)
A: Well absorbed.
D: Widely distributed.
M: Hepatic via CYP2D6 to morphine.
E: Renal.
Pharmacodynamics
Analgesia, antitussive action, decreased GI motility.
Synthesis Pathway
Formed from thebaine or morphine via O-methylation.
Safety, Warnings & Interactions
Adverse Effects
Drowsiness, constipation, respiratory depression.
Contraindications
Acute asthma, paralytic ileus.
Drug Interactions
CNS depressants, CYP2D6 inhibitors.
Pharmaceutics & Compendia
Dosage Forms
Tablets, Syrups
Official Compendia
IP, BP, USP