Bietaserpine is a derivative of a Rauwolfia alkaloid reserpine. It was used as an antihypertensive agent and marketed in the 1960s in France and Italy. Bietaserpine is believed to act by inhibiting VMAT receptors.

Ambrisentan (alternative Names: BSF 208075; GSK 1325760; GSK1325760A; Letairis) is an endothelin receptor antagonist that is selective for the endothelin type-A (ETA) receptor. The chemical name of ambrisentan is (+)-(2S)-2-[(4,6-dimethylpyrimidin-2-yl)oxy]-3-methoxy-3,3-diphenylpropanoic acid. Ambrisentan is indicated for the treatment of pulmonary arterial hypertension. It is approved in Europe, Canada and the United States for use as a single agent to improve exercise ability and delay clinical worsening. In addition, it is approved in the United States for use in combination with tadalafil to reduce the risks of disease progression, hospitalization and to improve exercise ability. As an endothelin receptor antagonist, ambrisentan prevents endogenous endothelin peptide from constricting the muscles in blood vessels, allowing them to relax and permit a reduction in blood pressure. Endothelin-1 (ET-1) is a potent autocrine and paracrine peptide. Two receptor subtypes, ETA and ETB, mediate the effects of ET-1 in the vascular smooth muscle and endothelium. The primary actions of ETA are vasoconstriction and cell proliferation, while the predominant actions of ETB are vasodilation, antiproliferation, and ET-1 clearance. In patients with PAH, plasma ET-1 concentrations are increased as much as 10-fold and correlate with increased mean right atrial pressure and disease severity. ET-1 and ET-1 mRNA concentrations are increased as much as 9-fold in the lung tissue of patients with PAH, primarily in the endothelium of pulmonary arteries. These findings suggest that ET-1 may play a critical role in the pathogenesis and progression of PAH. Ambrisentan is a high-affinity (Ki=0.011 nM) ETA receptor antagonist with a high selectivity for the ETA versus ETB receptor (>4000-fold). The clinical impact of high selectivity for ETA is not known.

Bosentan is a dual endothelin receptor antagonist important in the treatment of pulmonary artery hypertension (PAH). It is licensed in the United States, the European Union and other countries by Actelion Pharmaceuticals for the management of PAH under the trade name Tracleer®. Bosentan is used to treat pulmonary hypertension by blocking the action of endothelin molecules that would otherwise promote narrowing of the blood vessels and lead to high blood pressure. Bosentan competitively antagonizes the binding of 125I-labeled ET-1 to human vascular smooth muscle cells (predominantly ETA receptors) with an inhibition constant (Ki ) of 4.7 nM and to human placenta membranes (predominantly ETB receptors) with a Ki of 95 nM. Furthermore, bosentan is specific for endothelin receptors and does not interfere with the binding of a variety of peptides, neurotransmitters, growth factors, or eicosanoids to their receptors.

Pentaerythritol tetranitrate is an organic nitrate that has been used for the treatment of angina pectoris. Upon administration, the drug undergoes exstensive metabolism to NO which causes vasodilation and the relaxation of smooth muscle cells. The compound belongs to a familiy of explosive substances and may be used accordingly.

Pinacidil is a clinically effective vasodilator used for the treatment of hypertension.

Guanethidine belongs to the general class of medicines called antihypertensives. It was used to treat high blood pressure (hypertension). It is believed to act mainly by preventing the release of norepinephrine at nerve endings and causes depletion of norepinephrine in peripheral sympathetic nerve terminals as well as in tissues. It is taken up by norepinephrine transporters. It becomes concentrated in NE transmitter vesicles, replacing NE in these vesicles.

Indoramin is an alpha-1 selective antagonist of adrenergic receptor, sold under trade names Baratol and Doralese, and now available as a generic. It has no reflex tachycardia and direct myocardial depression action and is used to treat benign prostate hyperplasia (as 20 mg tablets) or reduce blood pressure (as 25 mg strength tablets). It was also investigated as a treatment of a migraine and congestive heart failure.