Profile of serum testosterone levels after application of testosterone ointment (Glowmin) and its clinical efficacy in late-onset hypogonadism patients

Introduction. Testosterone replacement therapy has been applied to alleviate the various symptoms of late-onset hypogonadism (LOH) patients. Several routes are available for the administration of testosterone to LOH patients, and transdermal delivery is an attractive method above all. Aim. The aim of this article was to clarify the profile of serum total testosterone (TT) and free testosterone (FT) levels after application of testosterone ointment (Glowmin [GL], Daito Pharmaceutical Co. Ltd., Tokyo, Japan) and its clinical efficacy in LOH patients. Methods. Serum TT and FT levels were examined in healthy male volunteers and LOH patients after application of 3 mg of GL. Then, 50 LOH patients received 3 mg of GL twice daily on scrotal skin (6 mg/day) for 12 weeks. Subsequently, TT and FT levels immediately prior to GL application were compared with those at 1 hour after GL treatment. Furthermore, the clinical effects of GL in the aforementioned 50 LOH patients were estimated after 12 weeks of GL treatment. Main Outcome Measures. Hormonal effects of GL were evaluated by serum TT and FT levels. Aging males symptoms (AMS), international index of erectile function (IIEF-5), and MOS 36-item short form Healthy Survey (SF-36) questionnaire were used to assess the clinical efficacy of GL for LOH patients. Results. Maximum TT and FT values, which were detected 1-2 hours after application of a 2-cm line of GL (3 mg of testosterone) to scrotal skin, were not elevated beyond physiological levels; subsequently, these levels returned to circadian rhythm after 4 hours in four healthy male volunteers. The highest TT and FT levels were also obtained after 1-2 hours in four LOH patients involving identical administration methods; moreover, these levels were maintained within a normal range for 6 hours. After 12 weeks of GL treatment in 50 LOH patients, TT and FT levels demonstrated the sane satisfactory response as that of the initial GL administration without GL accumulation effects. GL accumulation after 1 week in healthy men and after 12 weeks in LOH patients was not observed. Furthermore, AMS score decreased markedly; IIEF-5 and four domains of the SF-36 score were elevated significantly following GL application. Severe adverse reactions were not observed. Conclusions. Accordingly, GL, which is a short-acting testosterone ointment eliciting physiological elevation of TT and FT, appears to be suitable for LOH treatment.