Acetaminophen / Codeine — Opioid agonist + non-opioid analgesic combination. Study the mechanism, listed uses and warnings from the US label on one sourced card.
Generic name
Acetaminophen / Codeine
Class
Opioid agonist + non-opioid analgesic combination
Mechanism
Codeine is a mu-opioid agonist with weaker receptor affinity than morphine. Conversion to morphine may explain its analgesia, but the exact mechanism is unknown. Acetaminophen’s analgesic mechanism is not established and is thought to involve central actions.
Used for
Mild-to-moderate pain when an opioid is appropriate and alternative treatments are inadequate
Risks include addiction/abuse/misuse, fatal respiratory depression, fatal accidental ingestion or mg/mL dosing errors, CNS-depressant combinations, neonatal opioid withdrawal, and complex CYP interactions. Codeine can cause fatal respiratory depression in children and is contraindicated below age 12 or below age 18 after tonsillectomy/adenoidectomy. Acetaminophen can cause acute liver failure, particularly with excessive total doses or multiple acetaminophen products.
Warnings
Contraindicated in children younger than 12; Significant respiratory depression is a contraindication; Contraindicated for postoperative pain in children younger than 18 after tonsillectomy or adenoidectomy
Interactions
CYP2D6 inhibitors; CYP3A4 inhibitors; Benzodiazepines / other CNS depressants
Label date: 20260225 · For learning, not clinical decisions. US label and brand information; always consult the current source.
Source snapshot checked: 2026-10-21. The source document and selected fields were compared. The complete card has not had an independent clinical review.
Mechanism: Hydrocodone is a full opioid agonist with relative mu-receptor selectivity. Although its analgesia has no defined ceiling, respiratory and CNS adverse effects limit dosing. Acetaminophen has a separate analgesic action thought to involve central pathways; its precise mechanism is not established.
On both cards: Warnings — Significant respiratory depression is a contraindication · Interactions — CYP3A4 inhibitors
Only on the Hydrocodone / Acetaminophen card: Used for — Pain severe enough to require an opioid when alternative treatments are inadequate · Common side effects — Light-headedness; Dizziness; Sedation; Nausea; Vomiting · Warnings — Acute or severe bronchial asthma in an unmonitored setting or without resuscitative equipment is a contraindication; Known or suspected gastrointestinal obstruction, including paralytic ileus, is a contraindication · Interactions — Benzodiazepines / CNS depressants
Mechanism: A full opioid agonist with relative mu-receptor selectivity and analgesic activity. Although there is no defined ceiling for analgesia, respiratory and CNS adverse effects limit dosing.
On both cards: Common side effects — Constipation · Interactions — CYP3A4 inhibitors
Only on the Oxycodone card: Used for — Pain severe enough to require an opioid in adults when alternative treatments are inadequate · Common side effects — Nausea; Vomiting; Headache; Pruritus · Warnings — Opioid-induced hyperalgesia; Adrenal insufficiency; Severe hypotension · Interactions — Benzodiazepines / CNS depressants
Mechanism: Binds mu-opioid receptors and weakly inhibits reuptake of norepinephrine and serotonin; metabolite M1 is a more potent mu agonist.
On both cards: Common side effects — Constipation · Interactions — CYP2D6 inhibitors
Only on the Tramadol card: Used for — Severe, persistent pain in adults requiring an opioid when other options, including immediate-release opioids, cannot provide adequate control · Common side effects — Dizziness; Nausea; Headache; Somnolence · Warnings — Serotonin syndrome; Increased risk of seizures; Contraindicated in children under 12; This extended-release formulation is not intended for as-needed pain relief · Interactions — Serotonergic drugs, MAOIs; Benzodiazepines / CNS depressants
An item counts as shared only when both cards use the same wording. If a card does not list an item, that is not a statement that the effect never occurs.
Boxed warnings on related cards
Hydrocodone / Acetaminophen: Opioid addiction, misuse, fatal respiratory depression and accidental-ingestion overdose can occur. Combining with benzodiazepines, alcohol or other CNS depressants can cause coma or death; CYP3A4 interactions can increase opioid exposure. Prolonged use in pregnancy can cause life-threatening neonatal withdrawal. Acetaminophen can cause acute liver failure, including death, particularly with excessive total exposure or multiple acetaminophen-containing products.
Oxycodone: Risks include addiction, misuse, fatal respiratory depression and accidental-ingestion overdose. Benzodiazepines, alcohol or other CNS depressants can cause profound sedation, coma or death when combined with oxycodone. Extended use in pregnancy can cause life-threatening neonatal withdrawal. CYP3A4 inhibitors or stopping a CYP3A4 inducer can increase oxycodone exposure and overdose risk.
Tramadol: Addiction, misuse, fatal respiratory depression and accidental overdose can occur. Extended-release tablets must be swallowed whole to avoid a potentially fatal exposure. Benzodiazepines, alcohol or other CNS depressants can cause coma or death; prolonged pregnancy exposure can cause neonatal withdrawal. Use is contraindicated under age 12 and under age 18 after tonsillectomy or adenoidectomy. CYP3A4/CYP2D6 interactions can change tramadol and active-metabolite exposure.
Oxycodone / Acetaminophen: Risks include addiction, abuse, misuse, life-threatening respiratory depression and fatal accidental ingestion. Benzodiazepines or other CNS depressants can cause profound sedation, coma or death; prolonged pregnancy exposure can cause neonatal opioid withdrawal. CYP3A4 interactions can increase fatal respiratory risk. Acetaminophen can cause acute liver failure, liver transplantation or death, often with excessive or duplicate-product exposure.
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