Combined administration of levonorgestrel and testosterone induces more rapid and effective suppression of spermatogenesis than testosterone alone: a promising male contraceptive approach
Date
1996-02Author
Paulsen, C. Alvin
Christensen, Richard B.
Matsumoto, Alvin M.
Bremner, William J.
Bebb, Richard A.
Anawalt, Bradley D.
Metadata
Show full item recordAbstract
Studies using high dose testosterone (T) administration in normal men as a
male contraceptive have resulted in azoospermia rates of only 50-70%.
Previous studies of T and progestogen combinations have shown comparable
rates of azoospermia, but have been uncontrolled or used T in doses less
than that associated with maximal suppression of sperm production. We
conducted a randomized, placebo-controlled, single blind trial comparing 6
months of T enanthate administration (100 mg, im, weekly) with the same
dose of T enanthate in conjunction with the progestogen levonorgestrel
(LNG; 500 micrograms, orally, daily) in 36 normal men, aged 20-42 yr (n =
18 in each group). The primary end points were induction of azoospermia or
severe oligospermia (< 3 million sperm/mL). The combination of T plus LNG
was much more effective in suppressing sperm production than T alone.
Sixty-seven percent of the T plus LNG group (12 of 18) and 33% of the T
alone group (6 of 18) achieved azoospermia by 6 months (P = 0.06). Severe
oligospermia or azoospermia developed in 94% of the T plus LNG (17 of 18)
group compared to 61% of the T alone group (11 of 18; P < 0.05). T plus
LNG also suppressed sperm production more rapidly than T alone. Time to
azoospermia was 9.9 +/- 1.0 vs. 15.3 +/- 1.9 weeks in the T plus LNG and T
alone groups, respectively (mean +/- SEM; P < 0.05). Serum high density
lipoprotein cholesterol decreased 21.7 +/- 3.6% in men given T plus LNG (P
< 0.05), compared to only a 1.8 +/- 3.8% decrease in men in the T alone
group. Average weight gain was 5.3 +/- 0.8 kg in the T plus LNG group and
2.3 +/- 0.9 kg in the T alone group (P < 0.05). Acne and increase in
hemoglobin were similar in the two groups. We conclude that combination
hormonal therapy with T plus a progestogen might offer a reversible male
contraceptive approach with a more rapid onset of action and more reliable
induction of both azoospermia and severe oligospermia than T alone.