Last reviewed 2026-04-20 · How we verify

Codeine (codeine phosphate)

Codeine is a natural opiate prodrug requiring CYP2D6 conversion to morphine. Restricted in pediatric use due to pharmacogenomic safety concerns. Schedule II-V controlled substance (depending on formulation). Available generically.

At a glance

Approved indications

• Mild to Moderate Pain Management

Boxed warnings

• WARNING: ADDICTION, ABUSE, AND MISUSE: RISK EVALUATION AND MITIGATION STRATEGY (REMS), LIFE-THREATENING RESPIRATORY DEPRESSION; ACCIDENTAL INGESTION; ULTRA-RAPID METABOLISM OF CODEINE AND OTHER RISK FACTORS FOR LIFE- THREATENING RESPIRATORY DEPRESSION IN CHILDREN; NEONATAL OPIOID WITHDRAWAL SYNDROME; INTERACTIONS WITH DRUGS AFFECTING CYTOCHROME P450 ISOENZYMES; HEPATOTOXICITY; and RISKS FROM CONCOMITANT USE WITH BENZODIAZEPINES OR OTHER CNS DEPRESSANTS WARNING: SERIOUS AND LIFE-THREATENING RISKS FROM USE OF ACETAMINOPHEN AND CODEINE PHOSPHATE TABLETS Addiction, Abuse and Misuse Because the use of Acetaminophen and codeine phosphate tablets exposes patients and other users to the risks of opioid addiction, abuse and misuse, which can lead to overdose and death. Assess each patient’s risk prior to prescribing acetaminophen and codeine phosphate tablets and monitor all patients regularly for the development of these behaviors and conditions [see WARNINGS] . Life-Threatening Respiratory Depression Serious, life-threatening, or fatal respiratory depression may occur with use of acetaminophen and codeine phosphate tablets, especially during initiation or following a dosage increase. To reduce the risk of respiratory depression, proper dosing and titration of Acetaminophen and codeine phosphate are essential [see Warnings] . Accidental Ingestion Accidental ingestion of even one dose of Acetaminophen and codeine phosphate tablets, especially by children, can result in a fatal overdose of acetaminophen and codeine phosphate [see WARNINGS]. Risks from Concomitant Use with Benzodiazepines or Other CNS Depressants Concomitant use of opioids with benzodiazepines or other central nervous system (CNS) depressants, including alcohol, may result in profound sedation, respiratory depression, coma, and death. Reserve concomitant prescribing of acetaminophen and codeine phosphate tablets and benzodiazepines or other CNS depressants for use in patients for whom alternative treatment options are inadequate [see Warnings, Drug Interactions]. Neonatal Opioid Withdrawal Syndrome (NOWS) Advise pregnant women using opioids for an extended period of time of the risk of Neonatal Opioid Withdrawal Syndrome, which may be life threatening if not recognized and treated. Ensure that management by neonatology experts will be available at delivery [see WARNINGS]. Opioid Analgesic Risk Evaluation and Mitigation Strategy (REMS): Healthcare providers are strongly encouraged to complete a REMS compliant education program and to counsel patients and caregivers on serious risks, safe use, and the importance of reading the Medication Guide with each prescription [see Warnings] . Ultra-Rapid Metabolism of Codeine and Other Risk Factors for Life- Threatening Respiratory Depression in Children Life-threatening respiratory depression and death have occurred in children who received codeine. Most of the reported cases occurred following tonsillectomy and/or adenoidectomy and many of the children had evidence of being ultra-rapid metabolizers of codeine due to a CYP2D6 polymorphism [ see WARNINGS, PRECAUTIONS ; Information for Patients/Caregivers, Nursing Mothers ] . Acetaminophen and codeine phosphate tablets are contraindicated in children younger than 12 years of age and in children younger than 18 years of age following tonsillectomy and/or adenoidectomy (see CONTRAINDICATIONS). Avoid the use of acetaminophen and codeine phosphate tablets in adolescents 12 to 18 years of age who have other risk factors that may increase their sensitivity to the respiratory depressant effects of codeine. Interactions with Drugs Affecting Cytochrome P450 Isoenzymes The effects of concomitant use or discontinuation of cytochrome P450 3A4 inducers, 3A4 inhibitors, or 2D6 inhibitors with codeine are complex. Use of cytochrome P450 3A4 inducers, 3A4 inhibitors, or 2D6 inhibitors with acetaminophen and codeine phosphate tablets requires careful consideration of the effects on the parent drug, codeine, and the active metabolite, morphine. ( see WARNINGS, PRECAUTIONS: DRUG INTERACTIONS ) Hepatotoxicity Acetaminophen has been associated with cases of acute liver failure, at times resulting in liver transplant and death. Most of the cases of liver injury are associated with the use of acetaminophen at doses that exceed 4,000 milligrams per day, and often involve more than one acetaminophen-containing product [ see WARNINGS ].

Common side effects

• Nausea
• Drowsiness
• Dizziness
• Lightheadedness

Key clinical trials

• Combined Effect of Pregabalin and Oxycodone, and Lacosamide and Oxycodone, on Breathing: an Exploratory Study in Healthy Volunteers (The Polo Study) (Phase 4)
• Nausea in Patients Receiving Hydromorphone vs Oxycodone After Total Hip Replacement Surgery (Phase 4)
• A Comparative Study of Immediate-Release Oxycodone Capsules Versus Immediate-Release Morphine Tablets for the Treatment of Chinese Patients With Cancer Pain. (Phase 3)
• Effect of Propofol in Combination With Oxycodone on Anxiety State in Painless Abortion - A Multicenter Randomized Controlled Trial (EARLY/Phase 1)
• An Open-label, Randomised Study Comparing the Uptake of rIL-2 in HIV-1 Infected Individuals Receiving Different Combinations of Antiemetics and Analgesic Agents During rIL-2 Dosing in ESPRIT: Toxicity (Phase 3)
• Effects of Oxycodone Combined With Pregabalin on Chronic Postsurgical Pain in Spinal Surgery: a Randomized Control, Double-blinded, Factorial Design Trial (NA)
• A Randomized, Open-Label, 3-Period Crossover Study to Evaluate the Effect of Multiple Doses of DVS SR and Paroxetine on the CYP2D6 Biotransformation of Codeine to Morphine in Healthy Subjects. (Phase 1)
• A Phase 3, Open-Label Period Followed by a Randomized, Double-blind Placebo-controlled Study of the Analgesic Efficacy of Extended-release Hydrocodone/Acetaminophen (Vicodin CR) Compared to Placebo in (Phase 3)

Primary sources

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Competitive intelligence

For the full competitive landscape — auto-detected comparators, recent regulatory actions across the set, upcoming PDUFA, patent timeline, sponsor landscape:

• Codeine CI brief — competitive landscape report
• Codeine updates RSS · CI watch RSS
• Generic (multiple manufacturers) portfolio CI