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Phenobarbitone can precipitate acute intermittent porphyria (AIP) by inducing cytochrome P450 enzymes, increasing heme synthesis, and accumulating toxic precursors (ALA and PBG). This triggers acute attacks with severe abdominal pain, neuropsychiatric symptoms, autonomic dysfunction, and muscle weakness. Other porphyrinogenic drugs (phenytoin, carbamazepine, valproate) should also be avoided. Safe alternatives include benzodiazepines (lorazepam, diazepam) for seizures and gabapentin for neuropathic pain. Diagnosis is confirmed by increased urinary PBG. Treatment includes glucose, hemin, and avoiding triggers.