PapaverinePapaverVasodilator AgentsThebainePenile ErectionPhosphodiesterase InhibitorsChlorobutanolVasospasm, IntracranialPharmaceutical SolutionsInfusions, Intra-ArterialOpiumErectile DysfunctionPenisParasympatholyticsCinnarizineCapillary ElectrochromatographyTheophyllinePhysician-Patient RelationsUnited States Food and Drug AdministrationPhytotherapyDrugs, Chinese HerbalUnited StatesMolecular Sequence Data