Deserpidine is an ester alkaloid drug isolated from Rauwolfia canescens (family Apocynaceae) with antipsychotic and antihypertensive properties that has been used for the control of high blood pressure and for the relief of psychotic behavior. Rauwolfia alkaloids work by controlling nerve impulses along certain nerve pathways. As a result, they act on the heart and blood vessels to lower blood pressure. Deserpidine's mechanism of action is through inhibition of the ATP/Mg2+ pump responsible for the sequestering of neurotransmitters into storage vesicles located in the presynaptic neuron. The neurotransmitters that are not sequestered in the storage vesicle are readily metabolized by monoamine oxidase (MAO) causing a reduction in catecholamines.

CHLORISONDAMINE is a nicotinic acetylcholine receptor antagonist used as a ganglionic blocking agent in animal research. It was used precedently in the prolonged treatment of hypertension.

Rescinnamine is an alkaloid isolated from Rauvolfia serpentina and approved by FDA for the treatment of hypertension. The mechanism of rescinnamine is not established, but probably resembles that of reserpine. Rescinnamine approval was discontinued by unknown reason.

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.

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.

Reserpine is an alkaloid, isolated from the Rauwolfia serpentina plant and developed by Ciba pharma. Reserpine was approved by FDA for the treatment of hypertension and psychotic disorders. The drug exerts its effect by blocking two vesicular monoamine transporters, VMAT1 and VMAT2. The blockade results in vesicles that lose their ability to store neurotransmitter molecules. Neurotransmitters, thus retained in cytosol, are then neutralized by MAO.

Protoveratrine B is one of two alkaloids isolated from the plant Veratrum albumen. The main effect of both alkaloids is vasodilation in all vascular beds thereby reducing blood pressure. In the 1950's it was recognized that Protoveratrine B is the preferred compound which can be administered at significantly higher doses before the patient begins to vomit.

Protoveratrine A, the principal alkaloid of Veratrum album, has been used in the treatment of hypertension but has largely been replaced by drugs with fewer adverse effects.

Hexamethonium is a nicotinic cholinergic antagonist. It was used to treat hypertension, but has never been approved and was discontinued because of the non-specified treatment. When this drug tried to use in medical study via inhalation, one of the volunteer died, the death has been described as “particularly disturbing ”because it was a healthy volunteer who had no thing to gain by taking part in the study. This volunteer participated in a study designed to provoke a mild asthma attack in order to help doctors discover the reflex that protects the lungs of healthy people against asthma attacks. Hexamethonium is poorly absorbed from the gastrointestinal tract and does not cross the blood-brain barrier. Now it is widely used a research tool.

Tetraethylammonium is an experimental drug with no approved indication or marketed formulation. Tetraethylammonium blocks of apamin-sensitive and insensitive Ca2(+)-activated K+ channels. It is a weak agonist of the nicotinic receptor. Tetraethylammonium produces transient reductions in blood pressure. Tetraethylammonium hydroxide is used as a soluble source of hydroxide ions and in the synthesis of ionic organic compounds.