Betahistine is an orally administered, centrally acting histamine H1 receptor agonist with partial H3 antagonistic activity. It is proposed that betahistine may reduce peripherally the asymmetric functioning of the sensory vestibular organs in addition to increasing vestibulocochlear blood flow by antagonising local H3 heteroreceptors. Betahistine acts centrally by enhancing histamine synthesis within tuberomammillary nuclei of the posterior hypothalamus and histamine release within vestibular nuclei through antagonism of H3 autoreceptors. This mechanism, together with less specific effects of betahistine on alertness regulation through cerebral H1 receptors, should promote and facilitate central vestibular compensation. Betahistine is used to treat the symptoms associated with Ménière's disease, a condition of the inner ear which causes, vertigo (dizziness), tinnitus (ringing in the ears), hearing loss.

Pargyline is an irreversible selective monoamine oxidase (MAO)-B inhibitor, which possesses higher selectivity to this isoform in comparison with MAO-A. It was approved under brand name eutonyl for the treatment hypertension, but then this drug was discontinued.

Methdilazine is a phenothiazine compound with antihistaminic activity. Methdilazine binds to the histamine H1 receptor. This blocks the action of endogenous histamine, which subsequently leads to temporary relief of the negative symptoms brought on by histamine. It is used for the symptomatic relief of hypersensitivity reactions and particularly for the control of pruritic skin disorders.

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.

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.

Cyclandelate is a vasodilator developed for the treatment of cardiovascular diseases. The drug was used in many countries for such diseases as intermittent claudication, arteriosclerosis obliterans, thrombophlebitis, nocturnal leg cramps, local frostbite, Raynaud's phenomenon. In the USA it was also approved for intermittent claudication and cognitive dysfunction in Alzheimer's disease under the name Cyclospasmol. Cyclandelate exerts its effect by blocking calcium channels and inhibiting smooth muscles contration. Cyclandelate was withdrawn from the market in the USA for lack of effectiveness.

Syrosingopine, a drug derived from reserpine, which was investigated for the treatment of essential hypertension. The combination of syrosingopine and a mitochondrial inhibitor for the treatment of cancer and for achieving immunosuppression was patented. This invention also relates to a fluorescence-based method for predicting syrosingopine sensitivity of a cancer cell.

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.

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.

Deslanoside is a cardiotonic glycoside from the leaves of Digitalis lanata. It is used to treat congestive heart failure and supraventricular arrhythmias due to reentry mechanisms, and to control ventricular rate in the treatment of chronic atrial fibrillation. Deslanoside 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). It also acts on the electrical activity of the heart, increasing the slope of phase 4 depolarization, shortening the action potential duration, and decreasing the maximal diastolic potential.