Assessing safety in hormonal male contraception: a critical appraisal of adverse events reported in a male contraceptive trial

INTRODUCTION

There is unmet need for male contraceptive options, but a recent injectable combination male contraceptive trial was terminated early due to adverse events (AEs).

METHODS

We examined the frequency of reported AEs by male research participants compared with AEs reported in prescribing information of approved female hormonal contraceptive methods. Published data from trials of the top five most-used female hormonal contraceptives, supplemented by contemporary contraceptive research, were compared with the frequency of AEs reported in a male injectable hormonal contraceptive trial.

RESULTS

We observed similar frequencies of AEs reported by users of male contraceptives compared with those reported by female users. Among quantitatively comparable AEs, compared with men, women reported experiencing higher frequencies of headaches, pelvic pain, and weight gain and similar frequencies of decreased libido. Compared with women, men reported experiencing higher frequencies of acne and mood changes. Men discontinued participation due to AEs at a lower frequency than women.

CONCLUSIONS

Female hormonal methods generally have similar frequencies of AEs to those reported in a recent male hormonal contraceptive trial, and male users had lower rates of discontinuation due to AEs. There were fewer serious AEs of the male contraceptive than reported in contemporary female trials which resulted in FDA licensure. This suggests there may be implicit bias in the scientific community regarding the level of acceptable risk for users of male contraceptive methods.

Chiral separation ofrac-Ornidazole and detection of the impurity of (R)-Ornidazole in (S)-Ornidazole injection and raw material

(S)-Ornidazole is a subject of research as an antifertility agent in male animals at present. However, there seems to be no relative report on chiral separation for rac-Ornidazole, which has been used as an effective medicine for more than 30 years. In this article, the chiral separation of rac-Ornidazole on a Chiralcel OB-H column based on normal-phase high-performance liquid chromatography (NP-HPLC) is investigated and the methodology for detection of impurity of (R)-Ornidazole in (S)-Ornidazole injection and raw material is established. The novel mobile phase is utilized by mixing n-hexane, methanol and isopropyl alcohol (95:4:1, v/v/v) instead of the typical mobile phase of n-hexane and isopropyl alcohol, although the methanol, which offers a good resolution factor for the enantiomeric separation in this system, is not recommended on the Chiralcel OB-H column according to the instruction supplied by Daicel Chemical Ind., LTD (Japan).

Combined administration of low-dose gossypol acetic acid with desogestrel/mini-dose ethinylestradiol/testosterone undecanoate as an oral contraceptive for men

To evaluate the efficacy and feasibility of a new regimen of low-dose gossypol acetic acid (GA) combined with desogestrel/ethinylestradiol and testosterone undecanoate (DSG/E/TU) as a male contraceptive, adult male rats were fed orally with GA (12.5 mg/kg/day) and DSG (0.125 mg/kg)/E (0.025 mg/kg)/TU (100 mg/kg) daily for 8 weeks as loading dose until infertility, and a similar low dose of GA alone for infertility maintenance. Control animals were administered a single low dose of GA (12.5 mg/kg/day) or DSG (0.125 mg/kg)/E (0.025 mg/kg)/TU (100 mg/kg), and vehicle, respectively. Results demonstrated that the combined dosage regimen could damage epididymal sperm motility and density, and induce infertility within 8 weeks in rats; the infertility could be consistently sustained by giving single GA (12.5 mg/kg/day), and was reversible in about 8 weeks following withdrawal of gossypol. The regimen rendered treated male rats with spermiation failure within a period of 6-20 weeks of treatment. Also, the serum luteinizing hormone, follicle-stimulating hormone and testicular interstitial fluid testosterone levels showed a transient decrease at the end of 6 or 8 weeks, which returned to control levels after 8 weeks of recovery phase. No hypokalemia or other adverse effects in viscera were observed. These results provide a promising approach to using the new regimen for the development of an effective and reversible oral male contraceptive.

Effects of testosterone buciclate on testicular and epididymal sperm functions in bonnet monkeys (Macaca radiata)

The effects of testosterone buciclate (TB), a long-acting androgen ester given i.m. at four sites (20 mg/site) on days 1 and 91 of the study period (360 days), on reproductive and hormonal parameters were evaluated in five adult male bonnet monkeys; untreated animals (n = 5) acted as controls to monitor seasonal changes in these parameters. In control animals, testicular volume remained unchanged throughout the study; sperm count, motility and gel penetrability decreased while the percentage of spermatozoa showing retention of cytoplasmic droplet and coiled tail increased in June-July (days 210-240), preceded by reduction in serum testosterone (T) levels on days 120-150 (March-April). The TB-treated animals showed reduced testicular volume (days 90-270), suppressed sperm motility and gel penetrability (days 45-240 except on day 120), decreased sperm count (days 75-270), and an increased percentage of spermatozoa showing retention of cytoplasmic droplet and coiled tail (days 45-240 except on day 120). Even though serum T levels remained elevated until day 300, these levels were within the physiological range. The changes induced by TB were reversible. The suppression of testicular and epididymal functions by TB indicates that this long-acting androgen may have the potentiality to induce and maintain reversible sterility, but further evaluation needs to be carried out to develop an appropriate dosage regimen that would prevent return to normal functions in order to develop this long-acting androgen as a hormonal male contraceptive.(ABSTRACT TRUNCATED AT 250 WORDS)

Biological activity in the repopulating rat spermatocyte after the withdrawal of gossypol treatment. VI. Alteration in nuclear factors for interaction with histone gene promoter

This article reports the effects of gossypol at the genomic level in rat spermatogenic cells. After gossypol treatment for various times (8, 12, and 19 weeks), the spermatogonial cells were allowed to rest for 2 to 4 weeks. The function of histone H4 gene promoter (H4GP) in the repopulating pachytene spermatocytes (RPS) was investigated. The sequences of the oligonucleotides for the H4GP binding sites 1 and 2 were synthesized by an ABI-392 DNA synthesizer. RPS and the control pachytene spermatocytes (CPS) were obtained by centrifugal elutriation and subsequently they were used for the preparation of nuclear protein extracts (NPE). The NPE interaction with the DNA fragment of site 1 or 2 was studied by an electrophoresis mobility shift assay (EMSA). EMSA with NPE-CPS revealed ten major gel shift bands for site 1 and 2. The presence of extra unlabelled DNA fragments competed with 6 of the bands. After 2 to 4 weeks recovery from 8, 12, and 19 weeks of gossypol treatment, NPE-RPS failed to shift four bands (b through e) in site 1. These results suggested that gossypol treatment affected the transcription factors for interaction with site 1. On the contrary, no effect was demonstrated in NPE that interacted with site 2. Furthermore, gossypol treatment did not change the nucleotide sequence in the H4GP site 1 and 2.

Prospects for new hormonal male contraceptives

Overpopulation is a paramount global crisis, as it underlies virtually all major worldwide problems, including poverty, malnutrition, and warfare. It is imperative that proliferation be curbed by expediting reductions in fertility. This article discusses the demand for and acceptability of male contraceptives and the process of spermatogenesis. Endocrine control of spermatogenesis, and potential sites for disruption of male fertility, including steroid combinations and GnRH agonists and antagonists are reviewed also. Risks and benefits of these approaches are considered.