Berlafenone (previously known as GK 23 G), a sodium channel antagonist was studied as a class Ic antiarrhythmic agent, but development has been discontinued.

Pazoxide was studied as an antihypertensive agent. However, information about the current use of this drug is not available.

Disobutamide suppresses ventricular arrhythmias in several in vivo animal models. In particular, disobutamide suppressed ventricular arrhythmias in ouabain-toxic dogs and in dogs in which myocardial infarction. Clear cytoplasmic vacuolation associated with disobutamide is an example of a remarkable morphologic change not associated with apparent overt toxicity based on various functional tests. Clinically in the dog if vacuolation was associated with cell injury, one might expect a chronic debilitating condition as seen in the case of many spontaneous genetic storage diseases. Chronic heart failure or a gastrointestinal motility disorder might occur as a result of the changes in the musculature of coronary arteries or gastrointestinal wall, respectively. Disobutamide, because of its apparent low toxicity, can be recommended as useful for investigations aimed at determining the borderline between physiologic limits and toxicity of intracellular drug storage and for advancing knowledge of mechanisms involved in xenobiotics entry and storage in cells. Disobutamide was withdrawn from clinical testing when clear cytoplasmic vacuoles were found in the rat and dog during toxicity studies. Disobutamide induced vacuoles in all cell types except rat leukaemia. The drug induced cell death and reduction in confluency or cell count in cultures of all cell types except rat carcinoma and rabbit aorta muscle.

Modecainide is a benzanilide derivative patented by American pharmaceutical company Bristol-Myers Co. as type Ic antiarrhythmic agent. Modecainide is a major metabolite of Encainide, a class Ic antiarrhythmic, with comparable antiarrhythmic activity. Modecainide is never marketed because of its frequent proarrhythmic side effects.

Chloracyzine is phenothiazine derivative with vasodilatory activity. Chloracyzine produced a decrease in myocardial oxygen consumption accompanied by a reduction in coronary blood flow preceded by transient coronary dilatation. Chloracyzine produced an insignificant increase in arterial pressure; heart rate increased slightly in the open-chest experiments but not in the isolated heart. It is suggested that reduced oxygen uptake after chloracyzine is realized through improved efficiency in the use of oxygen.

Trimethamide is the antihypertensive agent.

Amotriphene (Myordil, WIN 5494) is a coronary dilator and cardiac antiarrhythmic properties. It has potential value in the treatment of angina-like conditions and the milder cardiac arrhythmias. Amotriphene binds to α‐adrenergic receptors.

Pentrinitrol is a metabolite of pentaerythritol tetranitrate. It has been introduced as an antianginal agent for man. Pentrinitrol decrease myocardial oxygen consumption and have a relatively long duration of action. The pharmacologic effects of pentrinitrol are similar to those of nitroglycerin. However, the duration of action of pentrinitrol is longer. Pentrinitrol produced lower pre-exercise systolic blood pressures and systolic blood pressures at point of angina. Pentrinitrol should permit patients to have fewer episodes of angina pectoris resulting from minor increases in physical activity. The same protection may also exist against angina pectoris produced by psychic stress. However, patients should still be cautioned against physical activity or psychic stress that ordinarily provokes angina pectoris.