Contraceptive, male, effect

Wu FC, Balasubramanian R, Mulders TM, Coelingh-Bennink HJ. Oral progestogen combined with testosterone as a potential male contraceptive additive effects between... 

The male barrier contraceptive device is known as the condom, or mbber, and is widely available in most countries. The condom is a mbber or latex sheath, sometimes packaged with a lubricant and spermicide, which serves as a cover for the penis and a receptacle for semen. The method is very effective if the condom is of good quaUty, remains on, and is replaced for each subsequent intercourse. It was reported that 6 biUion condoms were used in 1990 (101). Usage appears to be increasing as adjunctive use with other methods of contraception for prevention of HIV or other sexually transmitted diseases. By rough estimate, condoms may have been used in more than 13 biUion acts of sexual intercourse that risked unwanted pregnancy, HIV, and/or other sexually transmitted diseases (101). 

The concept of torsional asymmetry is not jnst an interesting abstract idea. Some years ago, fertility in some Chinese rnral commnnities was found to be below normal levels, and this was traced back to the presence of gossypol in dietary cottonseed oil. Gossypol acts as a male contraceptive, altering sperm matnration, spermatozoid motility, and inactivation of sperm enzymes necessary for fertilization. Extensive trials in China have shown the antifertility effect is reversible after stopping the treatment, and it has potential, therefore, as a contraceptive for men. 

Chowdhury, A. R. Effect of pharmacological agents on male reproduction. Adv Contracept Deliv Syst 1987 3(4) 347-352. 

The one product obtained from cottonseed oil, Gossypol which is categorized as non-hormonal selective spermatogenesis suppressant, is effective in producing azoospermia or severe oligospermia but it is not widely used as male contraceptive. Mechanism of action is not known. Adverse effects are edema, diarrhoea, hypokalemia, neuritis. 

Verapamil has been shown to block the P-glycoprotein responsible for the transport of many foreign drugs out of cancer (and other) cells (see Chapter 1) other calcium channel blockers appear to have a similar effect. This action is not stereospecific. Verapamil has been shown to partially reverse the resistance of cancer cells to many chemotherapeutic drugs in vitro. Some clinical results suggest similar effects in patients (see Chapter 54). Animal research suggests possible future roles of calcium blockers in the treatment of osteoporosis, fertility disorders and male contraception, immune modulation, and even schistosomiasis. 

Bebb RA, Anawalt BD, Christensen RB, Paulsen CA, Bremner WJ, Matsumoto AM. Combined administration of levonorgestrel and testosterone induces more rapid and effective suppression of spermatogenesis than testosterone alone a promising male contraceptive approach. J Clin Endocrinol Metab 1996 81(2) 757-62. 

Kassem, A., Al-Aghbari, A., Al-Habori, M. and Al-Mamary, M. (2006) Evaluation of the potential antifertility effect of fenugreek seeds in male and female rabbits. Contraception 73, 301-306. 

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