Testosterone therapy in microphallic hypospadias: topical or parenteral?

Local or systemic application of testosterone is reported to stimulate penile growth. Intramuscular testosterone has been found to be effective in 50% of patients; however, variable results have been reported with topical testosterone. The current study is an attempt to compare the efficacy of intramuscular versus topical testosterone application.

A total of 26 consecutive patients with hypospadias and small penis (<2SD for given age) were studied prospectively. These patients were recruited alternately into group A or group B. Each group consisted of 13 patients. In group A, penile growth was accomplished by topical application of testosterone (Testoviron, oily solution containing testosterone propionate, 25 mg, and testosterone enanthate, 110 mg, equivalent to about 100 mg of testosterone, Schering, Germany) with a dose of 2 mg/kg/wk, for 3 weeks. While in group B, testosterone (same preparation as above) was administered by intramuscular injection weekly for 3 consecutive weeks. Penile length, diameter, and secondary effects were recorded before, during, and 3 weeks after the therapy by a single observer.

Significant penile growth (P <.01) was noticed in both the groups of patients when compared with pretherapy with maximum response observed during the third week of therapy (reaching from an average pretherapy length of 2.0 cm and 1.8 cm to 3.18 cm and 3.11 cm posttherapy in group A and B patients, respectively). Seven patients in each group had growth of at least 50% compared with the initial size. The basal serum testosterone was within the normal range in both the groups. During therapy the serum testosterone was elevated above the basal level in all patients, but within the normal range except in 2 patients of group A. In these 2 children the serum testosterone level crossed the normal range. Linear growth did not alter significantly for the chronological age. Two patients of group A went on to have pubic hair, one of them had elevated testosterone level above the normal range. There was a surge in serum testosterone in all children, although significant penile enlargement was observed in 60% children in group A and 75% in group B.

Although the desired therapeutic effect of testosterone was achieved in both the groups, this study failed to show any significant difference between the 2 routes of administration. However, in group A, (topical) serum testosterone crossed the normal range in 15% of patients and was associated with significant reversible side effects.