Acetaminophen and codeine and Phenelzine interaction
Acetaminophen and codeine and Phenelzine: both prescribing labels flag this combination with the strongest language, such as a contraindication, a boxed warning, or an instruction to avoid it.
Do not combine without a prescriber's guidance. The label language below is the strongest FDA uses.
What the FDA labels say
From the Phenelzine (phenelzine sulfate) label · effective 2026-05-21
Phenelzine sulfate should not be used in combination with dextromethorphan or with CNS depressants such as alcohol and certain narcotics.
From the Acetaminophen and codeine (ACETAMINOPHEN AND CODEINE PHOSPHATE) label · effective 2026-01-22
…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…
Acetaminophen and codeine phosphate tablets should not be used in patients taking MAOIs or within 14 days of stopping such treatment.
Serotonin Syndrome Inform patients that opioids could cause a rare but potentially life-threatening condition resulting from concomitant administration of serotonergic drugs.
Interaction with Monoamine Oxidase Inhibitors Monoamine oxidase inhibitors (MAOIs) may potentiate the effects of morphine, codeine’s active metabolite, including respiratory depression, coma, and confusion.
Examples of these drugs include, selective serotonin reuptake inhibitors (SSRIs), serotonin and norepinephrine reuptake inhibitors (SNRIs), tricyclic antidepressants (TCAs), triptans, 5-HT3 receptor antagonists, drugs that affect the serotonin neurotransmitter system (e.g., mirtazapine, trazodone, tramadol), certain muscle relaxants (i.e., cyclobenzaprine, metaxalone),…
Taking more than these two? Interactions stack. Check your whole list at once; it stays in your browser.
Open in the checkerNot medical advice. Interaction Checker quotes FDA label text and NIH fact sheets. Whether an interaction matters for you depends on doses, timing, kidney and liver function, and other conditions. Confirm with a pharmacist or prescriber.