Fandosentan (CI 1034 or PD 180988) is an endothelin A receptor antagonist. It inhibits pulmonary vasoconstriction. Fandosentan was being developed for the treatment of chronic obstructive pulmonary disease and pulmonary hypertension.

Pyrinoline is a substituted 2,3-dicarboximide patented by McNeil Laboratories, Inc. for the treatment of cardiac arrhythmias.

Razinodil was developed as a coronary vasodilator, a drug that reduces blood pressure by dilating blood vessels. It was tested for its potential as a drug in ischemic myocardial diseases. In a canine heart-lung laboratory model, it increased coronary blood flow without increasing oxygen consumption. Only slight negative chronotropic (heart rate) and inotropic (cardiac contraction) effects were reported. Razinodil also improved the survival rate of miniature pigs after an induced heart attack.

Domipizone is a platelet aggregation inhibitor, cardiotonic and vasodilator.

Guanisoquin was found to be an effective antihypertensive agent that inhibited the monoamine oxidase.

Ditekiren is a relatively large renin inhibitor incorporating the hydroxyethylene isostere as well as both the P4 proline and P2’ isoleucine of angiotensinogen. Methylation of the P2-site histidine backbone nitrogen stabilizes the P2-P3 peptide bond towards degradation by chymotrypsin. Even though oral bioavailability was low, serum ditekiren levels were equivalent to 4–8 times the in vitro IC50 for renin inhibition for this peptide throughout the 2.5 h after oral administration that blood levels were monitored. In Na-depleted cynomolgus monkeys, oral dose elicited a hypotensive response that had not returned to baseline by 5 h. Ditekiren had been in phase II clinical trials for the treatment of heart failure and hypertension. However, these studies were discontinued.

IPRAMIDIL, a furoxan compound, revealed marked dilator activity in the coronary circulation of isolated working guinea pig hearts.

Naxifylline [CVT 124, BG 9719], a small molecule diuretic, is one of a new class of potent and highly selective adenosine A1 receptor antagonists discovered at University of Florida. Naxifylline is an A1 adenosine receptor antagonist used for the treatment of edema associated with congestive heart failure. Naxifylline appears to be one of the more potent and clearly the most A1-selective antagonist reported to date, with K1 values of 0.67 and 0.45 nM, respectively, at the rat and cloned human A1-receptors and with 1800-fold (rat) and 2400-fold (human) subtype selectivity. Naxifylline protects against the decline in renal function observed with diuretic therapy by promoting urine output.

Trecetilide is a class III antiarrhythmic agent developed for the treatment of atrial flutter and fibrillation. Trecetilide probably has effects on the cardiac myocyte membrane that are similar to ibutilide. It is being developed for both oral and intravenous administration. Unlike ibutilide, trecetilide has good oral bioavailability. Trecetilide has a good metabolic stability. As with ibutilide, its mechanism of class III action may involve both rectifier K+ current blockade and other mechanisms of prolonging repolarization.