Cholesterol - lowering drug: Clofibrate and gemfibrozil. (Lopid)

Parkinson medications: Levodopa (Dopar, Larodaopa).

Parkinson medications: Cimetidine (Tagamet), ranitidine (Zantac) and famotidine (Pepcid).

Anticoagulants:Coumarone and Heparin.

Agents for gout: Allopurinol (Loporin, Zyloprim).

Drugs derived from vitamin - A: Isotrethadione (Tridione).

Antidepressants: Tricylics, amphetamines.

Beta blocker-drugs for high blood pressure: atenolol (tenormin), metoprolol (Lopressor), nadolol (Corgard), propranolol (Inderal) and timolol (Blocadren).

Antithyroid agents: Carbimazole, iodine, thiocyanate thiouracil.

Others: Blood thinners, male hormones (anabolic steroids).