Two substances generally believed to be safe. Vast clinical experience of non-porphyrinogenicity.

Beta-blocker (metaprolol) + platelet inhibitor: (acetysalicylic acid). Metoprolol is metabolized in the liver by CYP 2D6. Metoprorlol: Thunell, patient reports (n=18): tolerated. Andersson, patient report (n=26): tolerated. South African list: use. French list: authorized. EPI: safe (betablockers). Acetylsalicylic acid: Kalman, Bonkowsky: believed to be safe. Michael Moore's list: safe. The Merck Manual: safe. Moore MR, Hift RJ: Drugs in the acute porphyrias. Cell Mol Biol. 43:89, 1997: safe. Eales L: Porphyria and the dangerous life-threatening drugs. S Afr Med J 56:914, 1979: safe.