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New search Medicine profile Codeine phosphate

Clinical medicine profile

Codeine phosphate

Opioid analgesic

High alert POM
Evidence state Source-linked Review date not recorded
Route
ORAL / IV / IM / SC / TD / RECTAL
Schedule
POM
ATC
Not assigned
PPB status
registered
Patient advice Check interactions
01 Risk first

Safety essentials

The information most likely to change a prescribing or dispensing decision.

Critical warning

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 ].

High-alert medicine — use an independent double-check during prescribing, preparation, and dispensing.

Contraindications

  • CONTRAINDICATIONS Acetaminophen and codeine phosphate tablets are contraindicated for: • All children younger than 12 years of age (see WARNINGS ). • Post-operative management in children younger than 18 years of age following tonsillectomy and/or adenoidectomy ( see WARNINGS ) .
  • Acetaminophen and codeine phosphate tablets are contraindicated in patients with: • Significant respiratory depression [ see WARNINGS ]. • Acute or severe bronchial asthma in an unmonitored setting or in the absence of resuscitative equipment [ see WARNINGS ] . • Concurrent use of monoamine oxidase inhibitors (MAOIs) or use of MAOIs within the last 14 days [ see WARNINGS ] . • Known or suspected gastrointestinal obstruction, including paralytic ileus [ see WARNINGS ] . • Hypersensitivity to codeine, acetaminophen, or any of the formulation excipients (e.g., anaphylaxis) [ see WARNINGS ] .

Precautions

  • WARNINGS Addiction, Abuse and Misuse: Acetaminophen and codeine phosphate tablets contain codeine.
  • Codeine in combination with acetaminophen, is a Schedule III controlled substance.
  • As an opioid, acetaminophen and codeine phosphate tablets expose users to the risks of addiction, abuse, and misuse [see DRUG ABUSE and DEPENDENCE ].
  • Although the risk of addiction in any individual is unknown, it can occur in patients appropriately prescribed acetaminophen and codeine phosphate tablets.
  • Addiction can occur at recommended dosages and if the drug is misused or abused.
  • The risk of opioid-related overdose or overdose-related death is increased with higher opioid doses, and this risk persists over the course of therapy.
  • In postmarketing studies, addiction, abuse, misuse, and fatal and non-fatal opioid overdose were observed in patients with long-term opioid use [ see ADVSERVE REACTIONS ].
  • Assess each patient’s risk for opioid addiction, abuse, or misuse prior to prescribing acetaminophen and codeine phosphate tablets, and reassess all patients receiving acetaminophen and codeine phosphate tablets for the development of these behaviors and conditions.
  • Risks are increased in patients with a personal or family history of substance abuse (including drug or alcohol abuse or addiction) or mental illness (e.g., major depression).
  • The potential for these risks should not, however, prevent the proper management of pain in any given patient.
  • Patients at increased risk may be prescribed opioids such as acetaminophen and codeine phosphate tablets, but use in such patients necessitates intensive counseling about the risks and proper use of acetaminophen and codeine phosphate tablets along with frequent reevaluation for signs of addiction, abuse, and misuse.
  • Consider recommending or prescribing an opioid overdose reversal agent [ WARNINGS, DOSAGE AND ADMINISTRATION ].
02 Point of care

Dosing matrix

Population and organ-function guidance, shown together for faster comparison.

Adult

DOSAGE AND ADMINISTRATION Important Dosage and Administration Instructions Acetaminophen and codeine phosphate tablets should be prescribed only by healthcare professionals who are knowledgeable about the use of opioids and how to mitigate the associated risks. Use the lowest effective dosage for the shortest duration of time consistent with individual patient treatment goals [see Warnings]. Because the risk of overdose increases as opioid doses increase, reserve titration to higher doses of Acetaminophen and codeine phosphate tablets for patients in whom lower doses are insufficiently effective and in whom the expected benefits of using a higher dose opioid clearly outweigh the substantial risks. Many acute pain conditions (e.g., the pain that occurs with a number of surgical procedures or acute musculoskeletal injuries) require no more than a few days of an opioid analgesic. Clinical guidelines on opioid prescribing for some acute pain conditions are available. There is variability in the opioid analgesic dose and duration needed to adequately manage pain due both to the cause of pain and to individual patient factors. Initiate the dosing regimen for each patient individually, taking into account the patient’s underlying cause and severity of pain, prior analgesic treatment and response, and risk factors for addiction, abuse, and misuse [see Warnings]. Respiratory depression can occur at any time during opioid therapy, especially when initiating and following dosage increases with Acetaminophen and codeine phosphate tablets]. Consider this risk when selecting an initial dose and when making dose adjustments [see Warnings ]. Patient Access to an Opioid Overdose Reversal Agent for the Emergency Treatment of Opioid Overdose Inform patients and caregivers about opioid overdose reversal agents (e.g., naloxone, nalmefene). Discuss the importance of having access to an opioid overdose reversal agent, especially if the patient has risk factors for overdose (e.g., concomitant use of CNS depressants, a history of opioid use disorder, or prior opioid overdose) or if there are household members (including children) or other close contacts at risk for accidental ingestion or opioid overdose. The presence of risk factors for overdose should not prevent the management of pain in any patient [ see WARNINGS; Addiction, Abuse, and Misuse; Life-Threatening Respiratory Depression; Risks from Concomitant Use with Benzodiazepines or Other CNS Depressants ]. Discuss the options for obtaining an opioid overdose reversal agent (e.g., prescription, over-the-counter, or as part of a community-based program). There are important differences among the opioid overdose reversal agents, such as route of administration, product strength, approved patient age range, and pharmacokinetics. Be familiar with these differences, as outlined in the approved labeling for those products, prior to recommending or prescribing such an agent. Initial Dosage Use of acetaminophen and codeine phosphate tablets as the First Opioid Analgesic Initiate treatment with acetaminophen and codeine phosphate tablets in a dosing range of 300 mg to 600 mg of acetaminophen and 15 mg to 60 mg of codeine phosphate every 4 hours as needed for pain, at the lowest dose necessary to achieve adequate analgesia. Titrate the dose based upon the individual patient’s response to their initial dose of Acetaminophen and Codeine Phosphate Tablets. The usual adult dosage is: Acetaminophen and Codeine P hosphate Tablets (codeine 15 mg and acetaminophen 300 mg): Take 1 to 2 tablets every 4 hours as needed for pain. Acetaminophen and Codeine Phosphate Tablets (codeine 30 mg and acetaminophen 300 mg): Take 1 to 2 tablet every 4 hours as needed for pain. Acetaminophen and Codeine Phosphate Tablets (codeine 60 mg and acetaminophen 300 mg): Take one tablet every 4 hours as needed for pain. Single Doses (Range) Maximum 24-Hour Dose Codeine Phosphate 15 mg to 60 mg 360 mg Acetaminophen 300 mg to 1,000 mg 4,000 mg The prescriber must determine the number of tablets per dose, and the maximum number of tablets per 24 hours, based upon the above dosage guidance. This information should be conveyed in the prescription. Conversion from Other Opioids to Acetaminophen and Codeine Phosphate Tablets There is inter-patient variability in the potency of opioid drugs and opioid formulations. Therefore, a conservative approach is advised when determining the total daily dosage of acetaminophen and codeine phosphate tablets. It is safer to underestimate a patient’s 24-hour acetaminophen and codeine phosphate tablets dosage than to overestimate the 24-hour acetaminophen and codeine phosphate tablets dosage and manage an adverse reaction due to overdose. Titration and Maintenance of Therapy Individually titrate acetaminophen and codeine phosphate tablets to a dose that provides adequate analgesia and minimizes adverse reactions. Continually reevaluate patients receiving acetaminophen and codeine phosphate tablets to assess the maintenance of pain control signs and symptoms of opioid withdrawal, and other adverse reactions, as well as reassessing for the development of addiction, abuse, or misuse [see WARNINGS ]. Frequent communication is important among the prescriber, other members of the healthcare team, the patient, and the caregiver/family during periods of changing analgesic requirements, including initial titration. If the level of pain increases after dosage stabilization, attempt to identify the source of increased pain before increasing the acetaminophen and codeine phosphate tablets dosage. If after increasing the dosage unacceptable opioid-related adverse reactions are observed, (including an increase in pain after dosage increase), consider reducing the dosage [see Warnings ]. Adjust the dosage to obtain an appropriate balance between management of pain and opioid-related adverse reactions. Safe Reduction or Discontinuation of acetaminophen and codeine phosphate tablets Do not rapidly reduce or abruptly discontinue acetaminophen and codeine phosphate tablets in patients who may be physically dependent on opioids. Rapid reduction or abrupt discontinuation of opioid analgesics in patients who are physically dependent on opioids has resulted in serious withdrawal symptoms, uncontrolled pain, and suicide. Rapid reduction or abrupt discontinuation has also been associated with attempts to find other sources of opioid analgesics, which may be confused with drug-seeking for abuse. Patients may also attempt to treat their pain or withdrawal symptoms with illicit opioids, such as heroin, and other substances. When a decision has been made to decrease the dose or discontinue therapy in an opioid-dependent patient taking acetaminophen and codeine phosphate tablets there are a variety of factors that should be considered, including the total daily dose of opioid (including acetaminophen and codeine phosphate tablets) the patient has been taking, the duration of treatment, the type of pain being treated, and the physical and psychological attributes of the patient. It is important to ensure ongoing care of the patient and to agree on an appropriate tapering schedule and follow-up plan so that patient and provider goals and expectations are clear and realistic. When opioid analgesics are being discontinued due to a suspected substance use disorder, evaluate and treat the patient, or refer for evaluation and treatment of the substance use disorder. Treatment should include evidence-based approaches, such as medication assisted treatment of opioid use disorder. Complex patients with co-morbid pain and substance use disorders may benefit from referral to a specialist. There are no standard opioid tapering schedules that are suitable for all patients. Good clinical practice dictates a patient-specific plan to taper the dose of the opioid gradually. For patients on acetaminophen and codeine phosphate tablets who are physically opioid-dependent, initiate the taper by a small enough increment (e.g., no greater than 10% to 25% of the total daily dose) to avoid withdrawal symptoms, and proceed with dose lowering at an interval of every 2 to 4 weeks. Patients who have been taking opioids for briefer periods of time may tolerate a more rapid taper. It may be necessary to provide the patient with lower dosage strengths to accomplish a successful taper. Reassess the patient frequently to manage pain and withdrawal symptoms, should they emerge. Common withdrawal symptoms include restlessness, lacrimation, rhinorrhea, yawning, perspiration, chills, myalgia, and mydriasis. Other signs and symptoms also may develop, including irritability, anxiety, backache, joint pain, weakness, abdominal cramps, insomnia, nausea, anorexia, vomiting, diarrhea, or increased blood pressure, respiratory rate, or heart rate. If withdrawal symptoms arise, it may be necessary to pause the taper for a period of time or raise the dose of the opioid analgesic to the previous dose, and then proceed with a slower taper. In addition, evaluate patients for any changes in mood, emergence of suicidal thoughts, or use of other substances. When managing patients taking opioid analgesics, particularly those who have been treated for an extended period of time and/or with high doses for chronic pain, ensure that a multimodal approach to pain management, including mental health support (if needed), is in place prior to initiating an opioid analgesic taper. A multimodal approach to pain management may optimize the treatment of chronic pain, as well as assist with the successful tapering of the opioid analgesic [see WARNINGS/ Withdrawal, DRUG ABUSE AND DEPENDENCE ].

Paediatric

See label paediatric section if present; otherwise use paediatric formulary — do not extrapolate adult doses.

Renal

Prefer fentanyl/methadone expert use over morphine in advanced CKD; reduce doses.

  • CrCl 0–120: Confirm renal dosing in product SmPC / primary label.
Hepatic

Reduce dose/frequency; avoid long-acting in decompensated disease.

03 Clinical use

Use, effects & interactions

Indications

  • INDICATIONS AND USAGE Acetaminophen and codeine phosphate tablets are indicated for the management of mild to moderate pain, where treatment with an opioid is appropriate and for which alternative treatments are inadequate.
  • Limitations of Use Because of the risks of addiction, abuse, misuse, overdose, and death, which can occur at any dosage or duration and persist over the course of therapy, reserve opioid analgesics, including acetaminophen and codeine phosphate tablets for use in patients for whom alternative treatment options are ineffective, not tolerated, or would be otherwise inadequate to provide sufficient management of pain.

Adverse effects

  • ADVERSE REACTIONS •The following serious adverse reactions are described, or described in greater detail, in other sections: • Addiction, Abuse, and Misuse [see WARNINGS ] • Life-Threatening Respiratory Depression [see WARNINGS ] • Neonatal Opioid Withdrawal Syndrome [see WARNINGS ] • Ultra-rapid Metabolizers of Codeine [see WARNINGS ] • Interactions with CNS Depressants [see WARNINGS ] • Severe Hypotension [see WARNINGS ] • Gastrointestinal Adverse Reactions [see WARNINGS ] • Seizures [see WARNINGS ] • Withdrawal [see WARNINGS ] • Opioid-Induced Hyperalgesia and Allodynia [See Warnings ] The following adverse reactions associated with the use of codeine were identified in post marketing reports.
  • Because some of these reactions were reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure.
  • Serious adverse reactions associated with codeine are respiratory depression and, to a lesser degree, circulatory depression, respiratory arrest, shock, and cardiac arrest.
  • The most frequently observed adverse reactions with codeine administration include drowsiness, lightheadedness, dizziness, sedation, shortness of breath, nausea, vomiting, sweating, and constipation.
  • Other adverse reactions include allergic reactions, euphoria, dysphoria, , abdominal pain, pruritus, rash, thrombocytopenia, and agranulocytosis.
  • Other less frequently observed adverse reactions expected from opioid analgesics, including acetaminophen and codeine phosphate tablets: Cardiovascular system: faintness, flushing, hypotension, palpitations, syncope Digestive System: abdominal cramps, anorexia, diarrhea, dry mouth, gastrointestinal distress, pancreatitis Nervous system: anxiety, drowsiness, fatigue, headache, insomnia, nervousness, shakiness, somnolence, vertigo, visual disturbances, weakness Skin and Appendages: rash, sweating, urticarial • Serotonin syndrome : Cases of serotonin syndrome, a potentially life-threatening condition, have been reported during concomitant use of opioids with serotonergic drugs. • Adrenal insufficiency : Cases of adrenal insufficiency have been reported with opioid use, more often following greater than one month of use. • Anaphylaxis : Anaphylaxis has been reported with ingredients contained in Acetaminophen and Codeine Phosphate Tablets. • Androgen deficiency : Cases of androgen deficiency have occurred with use of opioids for an extended period of time [see Clinical Pharmacology ]. · Hyperalgesia and Allodynia : Cases of hyperalgesia and allodynia have been reported with opioid therapy of any duration [see Warnings]. · Hypoglycemia : Cases of hypoglycemia have been reported in patients taking opioids.
  • Most reports were in patients with at least one predisposing risk factor (e.g., diabetes).
  • Opioid-induced esophageal dysfunction (OIED): Cases of OIED have been reported in patients taking opioids, and may occur more frequently in patients taking higher doses of opioid, and/or in patients taking opioids longer term [see WARNINGS ].
  • Adverse Reactions from Observational Studies A prospective, observational cohort study estimated the risks of addiction, abuse, and misuse in patients initiating long-term use of Schedule II opioid analgesics between 2017 and 2021.
  • Study participants included in one or more analyses had been enrolled in selected insurance plans or health systems for at least one year, were free of at least one outcome at baseline, completed a minimum number of follow-up assessments, and either: 1) filled multiple extended-release/long-acting opioid analgesic prescriptions during a 90 day period (n=978)
  • or 2) filled any Schedule II opioid analgesic for at least 70 of 90 days (n=1,244).
  • Those included also had no dispensing of the qualifying opioids in the previous 6 months.
  • Over 12 months: • approximately 1% to 6% of participants across the two cohorts newly met criteria for addiction, as assessed with two validated interviewbased measures of moderate-to-severe opioid use disorder based on Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) criteria, and • approximately 9% and 22% of participants across the two cohort newly met criteria for prescription opioid abuse and misuse [defined in DRUG ABUSE AND DEPENDENCE] , respectively, as measured with a validated self-reported instrument.
  • A retrospective, observational cohort study estimated the risk of opioid involved overdose or opioid overdose-related death in patients with new long-term use of Schedule II opioid analgesics from 2006 through 2016 (n=220,249).
  • WHO ladder still useful framework.
  • For cancer pain use around-the-clock + breakthrough.
  • Naloxone for overdose.
  • Document functional goals
  • review long-term opioid benefit regularly.
04 Pharmacology

Mechanism & disposition

Codeine is an opioid agonist relatively selective for the mu-opioid receptor, but with a much weaker affinity than morphine.

Codeine is an opioid agonist relatively se…The analgesic properties of codeine have b…The precise mechanism of the analgesic pro…
Read complete mechanism

Codeine is an opioid agonist relatively selective for the mu-opioid receptor, but with a much weaker affinity than morphine. The analgesic properties of codeine have been speculated to come from its conversion to morphine, although the exact mechanism of analgesic action remains unknown. The precise mechanism of the analgesic properties of acetaminophen is not established but is thought to involve central actions.

Onset

Minutes (IV) to hour (oral)

Duration

Hours (agent-dependent)

Route

ORAL / IV / IM / SC / TD / RECTAL

Metabolism

(conjugation) and subsequent renal

Elimination

of codeine is primarily via the kidneys, and about 90% of an oral dose is excreted by the kidneys within 24 hours of dosing. The urinary secretion products consist of free and glucuronide conjugated codeine (about 70%), free and conjugated norcodeine (about 10%), free and conjuga...

Half-life

is about 2.9 hours. The

05 Special populations

Pregnancy, lactation & diet

Pregnancy

Use only if necessary; neonatal withdrawal with chronic maternal use. Prefer specialist obstetric advice.

Lactation

Codeine generally avoided (CYP2D6). Short-term morphine sometimes used with monitoring — check guidance.

06 Kenya market

Brands & loaded prices

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07 Provenance

Sources & review state

Primary sourceLocal active-ingredient clinical extract; FDA drug label via OpenFDA/DailyMed; Professional class pharmacology (Opioid analgesic)
Last reviewedNot recorded
EvidenceSource-linked
Open source document ↗

Decision support only. Confirm patient-specific decisions against the current product SmPC, Kenya STG/EML, and professional judgement.