title: Viagra users should be cautious.
authors.forename: L
authors.initials: L
authors.lastname: Engle
mesh_terms: D000900:Anti-Bacterial Agents / Q000009:adverse effects; D004347:Drug Interactions; D017320:HIV Protease Inhibitors / Q000009:adverse effects*; D006801:Humans; D013287:Illicit Drugs; D018942:Macrolides; D008297:Male; D010726:Phosphodiesterase Inhibitors / Q000009:adverse effects* / Q000378:metabolism; D010879:Piperazines / Q000009:adverse effects* / Q000378:metabolism; D011687:Purines; D000068677:Sildenafil Citrate; D013450:Sulfones
chemical_list: D000900:Anti-Bacterial Agents; D017320:HIV Protease Inhibitors; D013287:Illicit Drugs; D018942:Macrolides; D010726:Phosphodiesterase Inhibitors; D010879:Piperazines; D011687:Purines; D013450:Sulfones; D000068677:Sildenafil Citrate