Belladonna and opium and Dextromethorphan and quinidine interaction
Belladonna and opium and Dextromethorphan and quinidine: 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 Belladonna and opium label · effective 2024-01-11
• Serotonergic Drugs: Concomitant use may result in serotonin syndrome.
Serotonergic Drugs Clinical Impact : The concomitant use of opioids with other drugs that affect the serotonergic neurotransmitter system has resulted in serotonin syndrome.
From the Dextromethorphan and quinidine (Nuedexta) label · effective 2026-01-22
Anticholinergic effects of quinidine: Monitor for worsening in myasthenia gravis and other sensitive conditions.
Anticholinergic Effects of Q uinidine Monitor for worsening clinical condition in myasthenia gravis and other conditions that may be adversely affected by anticholinergic effects.
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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.