TOLERABILITY OF INTRAMUSCULAR INJECTIONS OF TESTOSTERONE ESTER IN OILVEHICLE

We undertook a prospective survey of the tolerability of deep i.m. inj ections of testosterone enanthate in a castor oil vehicle, the most wi dely used form of androgen replacement therapy, Over a period of 8 mon ths, 26 men received 551 weekly injections into the gluteal, deltoid o r thigh muscle and side-effects were recorded immediately and 1 week a fter each injection by the same nurse using a standardized questionnai re, Most injections caused no complaints [389/551, 70.6% (95% confiden ce interval 66.6-74.4%)] but minor local side-effects, mostly pain and bleeding, were common [162/551, 29.4% (25.6-33.4%)]; no serious side- effects were observed, Considering all side-effects, the gluteal site had fewer complaints and was less prone to bleeding but was painful mo re often than deltoid or thigh injection sites, The laterality of inje ction at any site had no significant effect on side-effects. The only systemic side-effect was episodes of sudden-onset, non-productive coug h associated with faintness following eight injections [1.5% (0.6-2.9% )] which we speculate may have been due to pulmonary oil microembolism . We conclude that, when administered by an experienced nurse, deep i. m. injection of testosterone enanthate in a castor oil vehicle is gene rally safe and well tolerated but causes relatively frequent minor sid e-effects, including pain and bleeding, An improved depot form of test osterone would be highly desirable for androgen replacement therapy an d hormonal male contraception.