Phenobarbitone can precipitate acute intermittent porphyria (AIP)

• Phenobarbital acts as a potent inducer of hepatic cytochrome P450 enzymes, which in turn can increase the activity of ALA synthase, leading to overproduction of porphyrins.
• by inducing cytochrome P450 enzymes it 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.
• Safe alternatives include benzodiazepines (lorazepam, diazepam) for seizures and gabapentin for neuropathic pain.