Isoxsuprine (used as isoxsuprine hydrochloride) is a drug used as a vasodilator in humans (under the trade name Duvadilan) and equines. Isoxsuprine is a β2 adrenoreceptor agonist that causes direct relaxation of uterine and vascular smooth muscle via β2 receptors. Isoxsuprine it is used in humans for treatment of premature labor, i.e. a tocolytic, and as a vasodilator for the treatment of cerebral vascular insufficiency, Raynaud's phenomenon, and other conditions. Isoxsuprine may increase the heart rate, cause changes in blood pressure, and irritate the GI tract. It should, therefore, be used with caution if combined with other drugs that affect blood pressure, such as sedatives and anesthetic drugs. Isoxsuprine is most commonly used to treat hoof-related problems in the horse, most commonly for laminitis and navicular disease, as its effects as a vasodilator are thought to increase circulation within the hoof to help counteract the problems associated with these conditions.

Trimethaphan (or Trimethaphan camsylate), a ganglionic blocking agent and an antihypertensive drug, was marketed under the brand name Arfonad. Arfonad is indicated to induce systemic arterial hypotension in patients undergoing major surgery and to treat severe systemic hypertension, and in the emergency treatment of pulmonary edema in patients with pulmonary hypertension associated with systemic hypertension. Trimethaphan prevents stimulation of postsynaptic receptors by competing with acetylcholine for these receptor sites. Additional effects may include direct peripheral vasodilation and release of histamine. This drug was discontinued because of the competition from newer drugs that are more selective in their actions and effects.

Digoxin is a cardiac glycoside derived from the purple foxglove flower. In 1785, the English chemist, botanist, and physician Sir William Withering published his findings that Digitalis purpurea could be used to treat cardiac dropsy (congestive heart failure; CHF). Digoxin has been in use for many years, but was not approved by the FDA for treatment of heart failure (HF) until the late 1990s. Another FDA indication for digoxin is atrial fibrillation (AF). Digoxin also has numerous off-label uses, such as in fetal tachycardia, supra-ventricular tachycardia, cor pulmonale, and pulmonary hypertension. Digitoxin inhibits the Na-K-ATPase membrane pump, resulting in an increase in intracellular sodium and calcium concentrations. Increased intracellular concentrations of calcium may promote activation of contractile proteins (e.g., actin, myosin). Digoxin also has Para sympathomimetic properties. By increasing vagal tone in the sinoatrial and atrioventricular (AV) nodes, it slows the heart rate and AV nodal conduction.

Pentolinium (brand name Ansolysen) is a ganglionic cholinergic antagonist, acting on alpha 3 beta 4 neuronal nicotinic acetylcholine receptors (nAChRs). It was used as an antihypertensive drug during surgery or to control hypertensive crises, but Ansolysen was discontinued. Pentolinium inhibits release of adrenaline and noradrenaline from adrenergic nerves.

Dimoxyline is the synthetic analogue of papaverine, Acute toxicity studies show it to be less toxic than papaverine. No analgesic action and no tolerance development in experimental animals by repeated administration. But Dimoxyline does not appear to be as potent as papaverine in comparable dosage. Dimoxyline is indicated for the treatment of patients with angina pectoris. Also, significant amount of benefit was claimed in patients with acute or chronic phlebitis, arterial thrombosis or embolism, Raynaud’s phenomena and early thromboangiitis obliterans or arteriosclerosis obliterans. Detected adverse events are: nausea or abdominal cramps.

Nicotinyl alcohol is a direct-acting vasolidator, that may decrease the blood pressure and it is a cholesterol-lowering agent. Nicotinyl alcohol as a tartrate salt led to the efficiency improvements in patients with intermittent claudication. In addition, nicotinyl alcohol alone or associated with other drugs was studied in the treatment of radicular syndromes; and was shown, that the effect had not been due to mechanical compression.

Sparteine is a class 1a antiarrhythmic agent; a sodium channel blocker. It is the predominant alkaloid in Lupinus mutabilis, and is thought to chelate the bivalents calcium and magnesium. It is not FDA approved for human use as an antiarrhythmic agent. It is also used as a chiral base in organic chemistry, and as a ligand in organic chemical synthesis. Marketed under the brand name Spal in Taiwan and Sparteine in Brazil.

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.

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.

Vinburnine is a nutritional product, which is semi-synthesized from vincamine. It is a peripheral vasodilator with cerebral activities that also act as a cerebral metabolic stimulant and appears to be able to relax the smooth muscle cells within the walls of blood vessels. Some evidence also suggests that vinburnine stimulates acetylcholine neurotransmission. Acetylcholine is a very important neurotransmitter responsible for a number of cognitive functions, such as memory and learning.