Brands, Medical Use, Clinical Data
- Opiate Agonists
Brands / Synonyms
Acetaminophen with Codeine; Acetaminophen, Aspirin and Codeine; Airacof; Butalbital, Acetaminophen, Caffeine, and Codeine; Butalbital, Aspirin, Caffeine, and Codeine; Capital and Codeine; Codeine; Codeine anhydrous; Codeine Base [D.D]; Codeine [Anhydrous]; Codeprex Pennkinetic; Codicept; Codrix; Coducept; Fioricet with Codeine; Fiorinal with Codeine; L-Codeine; Lexuss; Methylmorphine; Morphine monomethyl ether; Norcodeine, N-Methyl; Norcodine, N-Methyl
; Promethazine and Codeine; Promethazine, Phenylephrine and Codeine; Pseudodine C; Soma Compound with Codeine; Triacin-C; Tylenol with Codeine
For treatment and management of pain (Systemic), also used as an Antidiarrheal and as a cough suppressant.
Codeine, an opiate agonist in the CNS, is similar to other phenanthrene derivatives such as morphine. Codeine, in combination with guaifenesin or iodinated glycerol, is used as a cough suppressant and, as a single agent or in combination with acetaminophen or other products, is used for pain control and as an antidiarrheal agent.
Mechanism of Action
Opiate receptors are coupled with G-protein receptors and function as both positive and negative regulators of synaptic transmission via G-proteins that activate effector proteins. Binding of the opiate stimulates the exchange of GTP for GDP on the G-protein complex. As the effector system is adenylate cyclase and cAMP located at the inner surface of the plasma membrane, opioids decrease intracellular cAMP by inhibiting adenylate cyclase. Subsequently, the release of nociceptive neurotransmitters such as substance P, GABA, dopamine, acetylcholine and noradrenaline is inhibited. Opioids also inhibit the release of vasopressin, somatostatin, insulin and glucagon. Codeine's analgesic activity is, most likely, due to its conversion to morphine. Opioids close N-type voltage-operated calcium channels (OP2-receptor agonist) and open calcium-dependent inwardly rectifying potassium channels (OP3 and OP1 receptor agonist). This results in hyperpolarization and reduced neuronal excitability.
Respiratory depression, sedation and miosis and common symptoms of overdose. Other symptoms include nausea, vomiting, skeletal muscle flaccidity, bradycardia, hypotension, and cool, clammy skin. Apnea and death may ensue
Biotrnasformation / Drug Metabolism
Hypersensitivity to codeine.
Codeine in combination with other narcotic analgesics, general anesthetics, phenothiazines, tranquilizers,
sedative-hypnotics, or other CNS depressants (including alcohol) has additive depressant effects. When s.c.
combination therapy is contemplated, the dosage of one or both agents should be reduced.