A triphasic oral contraceptive pill, CTR-05: clinical efficacy and safety.

OBJECTIVE: The primary objective of this study was to compare the safety, contraceptive efficacy, and menstrual cycle patterns in women using triphasic oral contraceptive pills, namely CTR-05, containing 50/100/150 micrograms desogestrel and 35/30/30 micrograms ethinylestradiol, and Orthonovum777 containing 500/750/1000 micrograms norethindrone and 35/35/35 micrograms ethinylestradiol. METHOD: Forty-six female volunteers, satisfying the selection criteria, were evaluated for six cycles, in an open-label, randomized study. Volunteers using CTR-05 were studied for 13 additional cycles for efficacy and safety. RESULTS: No serious adverse effects were observed in either group. The incidences of other drug-related adverse effects, such as headache and nausea, were transient in both groups. CTR-05 did not lower levels of high density lipoprotein (HDL) cholesterol. This may be attributed to the lower androgenicity of its progestin component, desogestrel. No pregnancies were reported in either group. Clinical and laboratory parameters remained within normal limits in both groups. In the CTR-05 group, the lower dose of ethinylestradiol did not affect the safety, efficacy and acceptability of the product. CONCLUSION: Desogestrel, with little estrogenic activity and only minimal androgenic activity, leads to lipoprotein changes, resulting in a favorable cardiovascular profile, as well as minimal androgen-related effects, such as hirsutism and acne.