The next nonprescription or herbal items may possibly communicate with sildenafil: cimetidine (Tagamet HB), St. John's wort. You'll want to Enable your doctor and pharmacist know that you are using these drugs before you start taking sildenafil.The AUC in the Lively metabolite, N-desmethyl sildenafil, was elevated sixty two% by loop and potassium-s