A 34 year-old male patient comes to your office after recently being diagnosed with acute porphyria. He takes insulin for diabetes, penicillin for sinusitis, ranitidine for acid reflux disorder, acetaminophen for headaches and butalbital for severe migraines. As you review his medications, he wonders whether it is safe to continue his current medications during porphyria. Which of the following drugs is not safe to take in acute porphyria?
