Potassium canrenoate (INN, JAN) or canrenoate potassium (USAN) (brand names Venactone, Soldactone), the potassium salt of canrenoic acid, is an aldosterone antagonist of the spirolactone group. Like spironolactone, it is a prodrug, which is metabolized to canrenone in the body. Potassium canrenoate is not licensed in the UK, but may sometimes be prescribed off-licence to treat oedema. It is given intravenously. Potassium canrenoate is a mineralocorticoid receptor (MR) antagonist. The blockade with MR antagonist have beneficial effects in patients with heart failure and myocardial infarction, often attributed to blocking aldosterone action in the myocardium.

Aminothiazole is a heterocyclic amine, commonly used as a starting point for synthesis of many compounds. In 1940s aminothiazole was used for the treatment of thyrotoxicosis. It has a direct action on the thyroid and acts by inhibiting T4 synthesis and accelerating its deiodination. Aminothiazole is an inhibitor of inducible NO synthetase (IC50 18 uM).

Atosiban (brand name Tractocile) is a competitive antagonist of human oxytocin at receptor level. In rats and guinea pigs, atosiban was shown to bind to oxytocin receptors, to decrease the frequency of contractions and the tone of the uterine musculature, resulting in a suppression of uterine contractions. Atosiban was also shown to bind to the vasopressin receptor, thus inhibiting the effect of vasopressin. Tractocile is indicated to delay imminent pre-term birth in pregnant adult women with: − regular uterine contractions of at least 30 seconds duration at a rate of ≥ 4 per 30 minutes − a cervical dilation of 1 to 3 cm (0-3 for nulliparas) and effacement of ≥ 50% − a gestational age from 24 until 33 completed weeks − a normal foetal heart rate. Atosiban does not have U.S. Food and Drug Administration (FDA) approval for use in the United States.

Epristeride is a steroid 5-alpha-reductase inhibitor developed for the treatment of prostatic hyperplasia and acne. The drug reached phase III clinical trial for hyperplasia in the UK, the US and Japan, however, the current status of the drug is unknown.

Cioteronel [CPC 10997, Cyoctol®, X-Andron] is an antiandrogen agent which was in phase II trials for androgenetic alopecia (male pattern baldness), and acne. It was also under development for the oral treatment of benign prostatic hyperplasia, but it was discontinued due to poor efficacy. CPC 10997 was found to be effective in vitro as an antiandrogen without effects on either the estrogen or the progesterone receptors in carcinomas of the breast, ovary and prostate as well as in malignant melanomas. CPC 10997 was found to be more effective against carcinomas of the breast, the kidney, the ovary and the prostate than conventional antineoplastic agents in the majority of tumors tested. The antineoplastic action of CPC 10997 appears to be the inhibition of RNA synthesis, but it has no detectable untoward effects on nonneoplastic cells, in vitro. Although it blocks competitively the binding of dihydrotestosterone (DHT) to its protein receptor, it has no significant effects on either estrogen or progesterone receptors. In view of the very favorable toxicology profiles and in vitro efficacy, further trials using CPC 10997 as an antineoplastic agent are indicated.

Zanoterone (or Win 49596), a steroidal androgen receptor antagonist was studied for the treatment of benign prostatic hyperplasia. The drug did not demonstrate a favorable risk-to-benefit profile and further development was stopped.

Carbimazole is a prodrug for methimazole used to treat hyperthyroidism and thyrotoxicosis during pregnancy and breast breastfeeding. Carbimazole is rapidly metabolized to methimazole, which is responsible for the antithyroid activity. Carbimazole is an antithyroid agent that decreases the uptake and concentration of inorganic iodine by the thyroid, it also reduces the formation of di-iodotyrosine and thyroxine. Once converted to its active form of methimazole, it prevents the thyroid peroxidase enzyme from coupling and iodinating the tyrosine residues on thyroglobulin, hence reducing the production of the thyroid hormones T3 and T4. Doses of carbimazole of 30 mg daily or 50 mg weekly have not adversely affected the few breastfed infants studied and no cases of thyroid function alteration have been reported among infants exposed to methimazole via breastmilk. Carbimazole is not approved for marketing in the United States by the U.S. Food and Drug Administration but is available in other countries.

Methylthiouracil is an orally active thyroid enzyme activity inhibitor. Methylthiouracil was introduced in the mid-1940s for the treatment of hyperthyroidism. Methylthiouracil is no longer in clinical use in most countries, although it may be used to a limited degree in some eastern European countries. Methylthiouracil possess anti-inflammatory effects in vitro and in vivo and was found effective in a murine model of sepsis.

Cyproterone acetate is a steroid drug which was developed by Schering A.G (now Bayer). Cyproterone acetate was approved in Canada, Asia, Latin America and Europe for the treatment of sever acne under the name Diane-35 (ethinyl estradiol) and its mechanism of action in this condition is explained by competitive inhibition of androgen receptor AR. In Canada cyproterone acetate is widely used as a contraceptive, however its usage is associated with liver toxicity and clots formation. In the UK the drug is marketed for the treatment of prostate cancer (Cyproterone acetate brand name).