Tropodifene (Tropaphen) is an α-Adrenergic receptor blocking agent. Clinical trials have shown that tropaphen has a beneficial effect on hypertension. Tropaphen has a very marked adrenolytic and vasodilator action. It greatly lowers the tone of the peripheral vessels. The preparation is effective starting with a dose of 0.1 mg/kg. After injection of the drug in a dose of 0.25 mg/kg, a considerable and gradually progressive decrease in the perfusion pressure takes place. The pressure falls by 30-35% and remained at a low level for 90-100 min. With a dose of tropaphen of 0.5 mg/kg, the perfusion pressure falls by 40-45% and remains low for 120 min or more. Strong vasodilatation is also observed after injection of tropaphen into intact rabbits.

Turosteride [FCE 26073] is a selective 5α-reductase inhibitor being developed by Pharmacia Corporation. Turosteride inhibits human and rat prostatic 5 alpha-reductases with IC50 values of 55 and 53 nM, respectively. It was in phase II clinical trials in Italy for the treatment of benign prostatic hyperplasia.

Flutonidine, an alpha2-adrenergic receptor agonist was studied as an antihypertensive drug. However, information about the current use of this drug is not available.

Mivazerol is a new and selective alpha 2-adrenoceptor agonist, devoid of hypotensive effects, which has been designed to prevent adverse cardiac outcome in perioperative patients with, or at risk coronary artery disease. This compound, which lacks hypotensive effects, has been demonstrated to prevent hyperadrenergic activity and myocardial ischemia in perioperative patients and tachycardia in rats at emergence from halothane anesthesia. This type of ischemia, frequently encountered in postoperative patients, is considered to be a consequence of stress-induced hyperactivation of the sympathetic system. Anti-ischemic effects of this compound have been demonstrated in different animal models of myocardial ischemia, and Mivazerol has also been shown to improve exercise-induced ischemia in patients with angina pectoris.

Tibalosin is a phenylethylamine derivative patented by Continental Pharma as a potent vasodilator. Tibalosine interacts specifically with alpha- and beta-adrenergic receptors and calcium channel binding sites. In preclinical models, Tibalosin exerts favor influences on arterial pressure in the hypertensive animal. The drug has acceptable toxicity in experimental animals and has been well tolerated by normal human subjects in daily doses of up to 200 mg.

Tiodazosin is a newly developed antihypertensive agent, structurally related to prazosin. Prazosin and tiodazosin administrated intravenously to anesthetized rats, are equally effective hypotensive agents, but that the hypotensive potency of prazosin is greater than that of tiodazosin. However, chronic administration of equivalent doses of the two compounds for 25 and 52 days via the drinking water indicated approximately equivalent, sustained reductions in blood pressure. Furthermore, at the end of the 52-day chronic dosing period tiodazosin caused appreciably less alpha-adrenergic receptor antagonist activity than prazosin as assessed by the norepinephrine dose-pressor response profiles.

Atiprosin (AY-28,228), an octahydro-pyrazino-pyrido-indole drug, possesses the alpha-adrenoceptor antagonist activity and exerts antihypertensive effects. Atiprosin has never been marketed

IZONSTERIDE, a benzoquinolinone, is a selective inhibitor of the 5-alpha reductase, with antagonistic effect on both the type I (liver, skin, hair follicles) and type II (prostate) isoforms of the enzyme. It is a competitive inhibitor of type I 5-alpha reductase and a non-competitive inhibitor of type II 5-alpha reductase. It was under development for the treatment of prostatic cancer.

Androsterone, a neurosteroid, acts as a positive allosteric modulator of GABA(A) receptors, that can cross into the brain and could have effects on brain function. It was discovered, that the association of beta subunits with alpha subunits GABA(A) receptor affects the sensitivity of glycine receptors to androsterone. In spite of that, androsteron is considered as an inactive metabolite of testosterone. In addition, was studied that androsterone possessed anticonvulsant properties. Although of low potency, the androsterone was present in high abundance and was able to represent endogenous modulator of seizure susceptibility.