codeine phosphate

codeine sulfate

Available forms
Available by prescription only
Injection: 15 mg/ml, 30 mg/ml, 60 mg/ml codeine phosphate
Oral solution: 15 mg/5 ml codeine phosphate
Tablets: 15 mg, 30 mg, 60 mg; 30 mg, 60 mg (soluble)

Indications and dosages
 Mild to moderate pain. Adults: 15 to 60 mg P.O. or 15 to 60 mg (phosphate) S.C. or I.M. q 4 to 6 hours, p.r.n., or around-the-clock.
Children age 1 and older: 0.5 mg/kg (or 15 mg/m²) P.O. q 4 to 6 hours, or 0.5 mg/kg (or 15 mg/m²) (phosphate) S.C. or I.M. q 4 to 6 hours.
 Nonproductive cough. Adults and children age 12 and older: 10 to 20 mg P.O. q 4 to 6 hours. Maximum dose is 120 mg/24 hours.
Children ages 6 to 11: 5 to 10 mg P.O. q 4 to 6 hours, not to exceed 60 mg daily.
Children ages 2 to 6: 1 mg/kg P.O. daily divided into four equal doses, administered q 4 to 6 hours, not to exceed 30 mg in 24 hours.

Pharmacodynamics
Analgesic action: Codeine (methylmorphine) has analgesic properties that result from its agonist activity at the opiate receptors.
Antitussive action: Codeine has a direct suppressant action on the cough reflex center.

Pharmacokinetics
Absorption: Well absorbed after oral or parenteral administration. It’s about two-thirds as potent orally as parenterally.
Distribution: Distributed widely throughout the body; it crosses the placental barrier and enters breast milk.
Metabolism: Metabolized mainly in the liver, by demethylation or by conjugation with glucuronic acid.
Excretion: Excreted mainly in the urine as norcodeine and free and conjugated morphine.

Contraindications and precautions
Contraindicated in patients hypersensitive to drug. Use cautiously in geriatric or debilitated patients and in patients with impaired renal or hepatic function, head injuries, increased intracranial pressure, increased CSF pressure, hypothyroidism, Addison’s disease, acute alcoholism, CNS depression, bronchial asthma, COPD, respiratory depression, or shock.

Interactions
Drug-drug. Anticholinergics: Concurrent use may cause paralytic ileus. Monitor patient closely.
Antihistamines, barbiturates, benzodiazepines, CNS depressants, general anesthetics, MAO inhibitors, muscle relaxants, narcotic analgesics, phenothiazines, sedative-hypnotics, tricyclic antidepressants: Potentiates drug’s respiratory and CNS depression, sedation, and hypotensive effects. Use together with extreme caution.
Cimetidine: Increases respiratory and CNS depression. Avoid use together.
Digitoxin, phenytoin, rifampin: May cause drug accumulation and enhanced effects. Monitor patient closely.
Drug-lifestyle. Alcohol use: Potentiates respiratory and CNS depression, sedation, and hypotensive effects of drug. Discourage alcohol use.

Adverse reactions
CNS: sedation, clouded sensorium, euphoria, dizziness, light-headedness.
CV: hypotension, flushing, bradycardia.
GI: nausea, vomiting, constipation, dry mouth, ileus, increased plasma amylase and lipase levels.
GU: urine retention.
Respiratory: respiratory depression.
Skin: pruritus, diaphoresis.
Other: physical dependence.

Effects on lab test results
• May increase amylase and lipase levels.

Overdose and treatment
The most common signs and symptoms of overdose are CNS depression, respiratory depression, and miosis (pinpoint pupils). Other acute toxic effects include hypotension, bradycardia, hypothermia, shock, apnea, cardiopulmonary arrest, circulatory collapse, pulmonary edema, and seizures.
 To treat acute overdose, first establish adequate respiratory exchange via a patent airway and ventilation as needed; administer narcotic antagonist (naloxone) to reverse respiratory depression. (Because the duration of action of codeine is longer than that of naloxone, repeated naloxone dosing is needed.) Naloxone shouldn’t be given unless the patient has clinically significant respiratory or CV depression. Monitor vital signs closely.
 If patient shows signs and symptoms within 2 hours of ingestion of an oral overdose, empty the stomach immediately by inducing emesis with ipecac syrup or using gastric lavage. Use caution to avoid risk of aspiration. Administer activated charcoal via nasogastric tube for further removal of drug in an oral overdose.
 Provide symptomatic and supportive treatment (continued respiratory support, correction of fluid or electrolyte imbalance). Monitor laboratory parameters, vital signs, and neurologic status closely.

Special considerations
 ALERT Don’t mix with other solutions because codeine phosphate is incompatible with many drugs.
• Codeine and aspirin have additive analgesic effects. Give together for maximum pain relief.
• Codeine has a much lower abuse potential than morphine.
• Patients who become physically dependent on drug may experience acute withdrawal syndrome if given a narcotic antagonist.
• Drug may delay gastric emptying, increase biliary tract pressure resulting from contraction of the sphincter of Oddi, and may interfere with hepatobiliary imaging studies.
Breast-feeding patients
• Drug appears in breast milk; assess risk-to-benefit ratio before administering.
Pediatric patients
• Administer cautiously to children. Codeine-containing cough preparations may be hazardous in young children. Use a calibrated measuring device and don’t exceed the recommended daily dose.
Geriatric patients
• Lower doses are usually indicated for elderly patients, who may be more sensitive to the therapeutic and adverse effects of drug.

Patient education
• Inform patient that codeine may cause drowsiness, dizziness, or blurred vision; tell him to use caution while driving or performing tasks that require mental alertness.
• Instruct patient to ask for or to take drug before pain is intense.
• Advise patient that GI distress from oral medication can be lessened when drug is taken with milk.

Reactions may be common, uncommon, life-threatening, or COMMON AND LIFE THREATENING.
◆ Canada only
◇ Unlabeled clinical use