SulfonesPurinesPiperazinesPhosphodiesterase InhibitorsPhosphodiesterase 5 Inhibitors3',5'-Cyclic-GMP PhosphodiesterasesErectile DysfunctionIndians, North AmericanCyclic Nucleotide Phosphodiesterases, Type 5IndiaIndian OceanHomosexuality, MalePenile ErectionMethamphetamineVasodilator AgentsCyclic GMPGeorgiaUnited States Indian Health ServiceIndians, South AmericanIndian Ocean IslandsUnsafe SexAlaskaRisk-TakingArizonaSexual BehaviorInuitsSouth DakotaNew MexicoOklahomaMalaysiaIndians, Central AmericanNorth DakotaEthnic GroupsMedicine, AyurvedicWest IndiesSingaporeAsian Continental Ancestry GroupEuropean Continental Ancestry GroupSouthwestern United StatesPrevalenceUnited StatesMontanaComorosAsia