They include: Ketoconazole (an anti-fungal) Sulfasalazine (for inflammatory bowel disease) Spironolactone (an anti-hypertensive) Calcium Channel Blockers (anti- hypertensives) Allopurinol, Colchicine (for gout) Antibiotics: Nitrofuran, Erythromycin, Gentamicin Methotrexate (cancer, psoriasis,...