Chlorzoxazone and Physostigmine interaction
Chlorzoxazone and Physostigmine: the Physostigmine prescribing label flags 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 Physostigmine (ANTICHOLIUM) label · effective 2025-11-11
…obstruction, spasms in the urinary tract collection system, inactivation of nerve and muscle cells after administration of drugs to relax the muscles (depolarization block after depolarizing muscle relaxants), in case of intoxication due to “irreversibly acting” cholinesterase inhibitors (drugs used to treat dementia), intoxication with phosphoric acid esters or barbiturates.
In intoxication with depolarizing muscle relaxants of the suxamethonium type, ANTICHOLIUM ® is contraindicated!
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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.