Show pageOld revisionsBacklinksBack to top This page is read only. You can view the source, but not change it. Ask your administrator if you think this is wrong. **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.