Dihydrotestosterone (DHT) (referred to as androstanolone or stanolone when used medically) can also be used in place of testosterone as an androgen. The availability of DHT is limited; it is not available in the United States or Canada, for instance, but it is available in certain European countries, including the United Kingdom , France , Spain , Belgium , Italy , and Luxembourg .  DHT is available in formulations including topical gel, buccal or sublingual tablets, and as esters in oil for intramuscular injection.  Relative to testosterone, and similarly to many synthetic AAS, DHT has the potential advantages of not being locally potentiated in so-called androgenic tissues that express 5α-reductase (as DHT is already 5α-reduced) and of not being aromatized into an estrogen (it is not a substrate for aromatase).
Anticoagulants: Patients on anticoagulants such as warfarin should be carefully monitored during anabolic steroid therapy as anabolic steroids may increase sensitivity to oral anticoagulants which may require a concomitant reduction in anticoagulant dosage to achieve a desirable prothrombin time (PT). Anticoagulant patients should be monitored regularly during anabolic steroid therapy, particularly during initiation and termination of therapy. Warfarin patients should have INR and PT monitored throughout androgen therapy and warfarin dosages titrated to achieve the desired INR and PT. Such patients should be monitored for occult bleeding.
The first isolation and structure identifications of prednisone and prednisolone were done in 1950 by Arthur Nobile .    The first commercially feasible synthesis of prednisone was carried out in 1955 in the laboratories of Schering Corporation, which later became Schering-Plough Corporation , by Arthur Nobile and coworkers.  They discovered that cortisone could be microbiologically oxidized to prednisone by the bacterium Corynebacterium simplex. The same process was used to prepare prednisolone from hydrocortisone .