sildenafil, tadalafil
Hormone replacement: cortisol, estradiol, methylprednisolone, progesterone, testosterone
Immunosuppressants: cyclosporine, sirolimus, tacrolimus
HMG-CoA reductase inhibitors: atorvastatin, fluvastatin, lovastatin, simvastatin
Opioids: alfentanil, fentanyl, sufentanil
Selective serotonin reuptake inhibitors: fluvoxamine, sertraline
Xanthine: theophylline