Concurrent use of Paracetamol and Barbiturates (eg, phenobarbital): The potential hepatotoxicity of acetaminophen may be increased when large or chronic dose of barbiturates are coadministered. The therapeutic effects of acetaminophen may be reduced with barbiturate therapy.
Charcoal, activated: Charcoal can reduce the GI absorption of acetaminophen when administered as soon as possible after overdose.
Hydantoins (eg. phenytoin): The potential hepatotoxicity of acetaminophen may be increased when coadministered with sulfinperazone. The therapeutic effects of acetaminophen may be reduced with sulfinpyrazone therapy.
Isoniazid: May increase the risk of liver toxicity. Administer acetaminophen with caution to patients receiving isoniazid.
Lamotrigine: Serum lamotrigine concentrations may be reduced, producing a decrease in therapeutic effects. A clinically important interaction is unlikely to occur with a single dose or several doses of acetaminophen, if an interaction is suspected adjust the dose of lamotrigine if needed.
Sulfinpyrazone: the potential hepatotoxicity of acetaminophen may be increased when coadministered with sulfinpyrazone. The therapeutic effects of acetaminophen may be reduced with sulfinpyrazone therapy.