An alkaloid found in opium but not closely related to the other opium alkaloids in its structure or pharmacological actions. Papaverine is a vasodilating agent. Papaverine is used for the treating certain conditions that are accompanied by smooth muscle spasms (eg, blood vessel, urinary, gallbladder, or intestinal spasm). Papaverine is a nonxanthine phosphodiesterase inhibitor for the relief of cerebral and peripheral ischemia associated with arterial spasm and myocardial ischemia complicated by arrhythmias. The main actions of Papaverine are exerted on cardiac and smooth muscle. Like qathidine, Papaverine acts directly on the heart muscle to depress conduction and prolong the refractory period. Papaverine relaxes various smooth muscles. This relaxation may be prominent if spasm exists. The muscle cell is not paralyzed by Papaverine and still responds to drugs and other stimuli causing contraction. The antispasmodic effect is a direct one, and unrelated to muscle innervation. Papaverine is practically devoid of effects on the central nervous system. Papaverine relaxes the smooth musculature of the larger blood vessels, especially coronary, systemic peripheral, and pulmonary arteries. Papaverine is a potent, specific inhibitor of PDE10A. Papaverine for treatment of erectile dysfunction (ED) is excluded from coverage.

Trimegestone is a 19-norpregnane progestin. It has a potent progesterone receptor and very low androgen receptor affinities but no detectable affinity to oestrogen receptor. Trimegestone has been developed for use in conjunction with oestrogen and 17-beta-estradiol for postmenopausal hormone replacement therapy. In vitro studies have shown that trimegestone can inhibit cytochrome P450 2C19 (CYP2C19). Although its clinical importance is unknown, trimegestone can moderately elevate the plasma concentration of drugs metabolized through CYP2C19, such as citalopram, imipramine and diazepam. Trimegestone is an effective and well-tolerated new progestin, which does not negate the beneficial effects of oestrogen on lipids.

Azanidazole (or Triclose), an antitrichomonal agent that is used to treat the vaginal trichomoniasis in Italy. This drug causes genotoxicity in liver and kidney that is not separated from its biological activity.

Medrogestone is a progesterone derivative used for the treatment of progesterone deficiency, especially those observed in the premenopausal period, haemorrhages and menorrhagia of fibroids, endometriosis, menstrual cycle disorders, etc. The drug acts by binding and activating progesterone receptors. In Europe, medrogestone is available under the name Colprone, however it is no longer marketed in the USA, Germany and Austria.

Nifuratel is a furane-derivative provided with a strong trichomonicidal activity; it has a broad antibacterial spectrum of action, including both Gram-negative and Gram-positive organisms. It is active against Chlamydia trachomatis and Mycoplasma spp. and has also some degree of activity against Candida spp. and mycetes. The action mechanism of nitrofurans has not been fully elucidated, and it may be the inhibiting of acetyl coenzyme A interfere with the early stages of bacterial glucose metabolism. Nifuratel alone or in complex with nystatin is indicated for the treatment of vulvovaginal and urinary tract infections. The drug is not approved by FDA.

17α-Hydroxyprogesterone (17α-OHP), or hydroxyprogesterone (OHP), also known as 17α-hydroxypregn-4-ene-3, 20-dione is used under the brand name Gestageno, and has been marketed for clinical use in Argentina. It was indicated for female infertility, hypertrichosis, menstrual disorders, premature labour, threatened or recurrent miscarriage. It is used to properly regulate the menstrual cycle and treat unusual stopping of the menstrual periods (amenorrhea). To help a pregnancy occur during egg donor or infertility procedures in women who do not produce enough progesterone. To prevent estrogen from thickening the lining of the uterus (endometrial hyperplasia) in women around menopause who are being treated with estrogen for ovarian hormone therapy (OHT). To treat a condition called endometriosis, to help prevent endometrial hyperplasia, or to treat unusual and heavy bleeding of the uterus (dysfunctional uterine bleeding) by starting or stopping the menstrual cycle. 17α-OHP is an agonist of the progesterone receptor (PR) similarly to progesterone. In addition, it is an antagonist of the mineralocorticoid receptor (MR) as well as a partial agonist of the glucocorticoid receptor (GR), albeit with very low potency (EC50 >100-fold less relative to cortisol) at the latter site, also similarly to progesterone.

Sulprostone, a P1/EP3 prostanoid receptor agonist, participated in trials for ending pregnancy after fetal death between 14 and 42 weeks gestation. This drug was also studied for treating severe atonic postpartum hemorrhage after vaginal delivery and for management of retained placenta. Moreover, recent investigations have revealed, that sulprostone could be a valuable drug candidate in the therapy of many pathophysiological states, including ulcerative colitis, glaucoma, and bone healing.

Sulfatolamide is a combination of two sulfonamide antibacterials, sulfathiourea and mafenide, previously used in the treatment of gynecological infections.

Mesterolone is an androgen receptor agonist which was developed for hormone replacement therapy in males suffering from androgen deficiency and related disorders. Mesterolone is known under the name Proviron. The drug is also used by bodybuilders and athletes.

Promegestone (R 5020) is a potent progestin devoid of androgenic side-effects and has marked anti-estrogenic activity. Promegestone is an AChR noncompetitive antagonist that may alter AChR function by interactions at the lipid-protein interface. Promegestone is used in the treatment of gynecological disorders due to luteal insufficiency.