A phosphodiesterase (PDE) is an enzyme that breaks a phosphodiester bond. Usually, phosphodiesterase refers to cyclic nucleotide phosphodiesterases, which have great clinical significance and are described below. However, there are many other families of phosphodiesterases, including phospholipases C and D, autotaxin, sphingomyelin phosphodiesterase, DNases, RNases, and restriction endonucleases, as well as numerous less-well-characterized small-molecule phosphodiesterases.
Diltiazem, sold under the brand name Cardizem among others, is a calcium channel blocker medication used to treat high blood pressure, angina, and certain heart arrhythmias. It may also be used in hyperthyroidism if beta blockers cannot be used. It is taken by mouth or injection into a vein. When given by injection, effects typically begin within a few minutes and last a few hours.
A phosphodiesterase type 5 inhibitor is a vasodilating drug that works by blocking the degradative action of cGMP-specific phosphodiesterase type 5 (PDE5) on cyclic GMP in the smooth muscle cells lining the blood vessels supplying various tissues. These drugs dilate the corpora cavernosa of the penis, facilitating erection with sexual stimulation, and are used in the treatment of erectile dysfunction (ED). Sildenafil was the first effective oral treatment available for ED. Because PDE5 is also present in the smooth muscle of the walls of the arterioles within the lungs, two PDE5 inhibitors, sildenafil and tadalafil, are FDA-approved for the treatment of pulmonary hypertension. As of 2019, the wider cardiovascular benefits of PDE5 inhibitors are being appreciated.
Moxonidine (INN) is a new-generation alpha-2/imidazoline receptor agonist antihypertensive drug licensed for the treatment of mild to moderate essential hypertension. It may have a role when thiazides, beta-blockers, ACE inhibitors, and calcium channel blockers are not appropriate or have failed to control blood pressure. In addition, it demonstrates favourable effects on parameters of the insulin resistance syndrome, apparently independent of blood pressure reduction. It is also a growth hormone releaser. It is manufactured by Solvay Pharmaceuticals under the brand name Physiotens & Moxon.
Bisoprolol, sold under the brand name Zebeta among others, is a beta blocker medication used for heart diseases. This includes tachyarrhythmias, high blood pressure, chest pain from not enough blood flow to the heart, and heart failure. It is taken by mouth.
Nicorandil is a vasodilatory drug used to treat angina.
Milrinone, sold under the brand name Primacor, is a pulmonary vasodilator used in patients who have heart failure. It is a phosphodiesterase 3 inhibitor that works to increase the heart's contractility and decrease pulmonary vascular resistance. Milrinone also works to vasodilate which helps alleviate increased pressures (afterload) on the heart, thus improving its pumping action. While it has been used in people with heart failure for many years, studies suggest that milrinone may exhibit some negative side effects that have caused some debate about its use clinically.
Amrinone, also known as inamrinone, and sold as Inocor, is a pyridine phosphodiesterase 3 inhibitor. It is a drug that may improve the prognosis in patients with congestive heart failure. Amrinone has been shown to increase the contractions initiated in the heart by high-gain calcium induced calcium release (CICR). The positive inotropic effect of amrinone is mediated by the selective enhancement of high-gain CICR, which contributes to the contraction of myocytes by phosphorylation through cAMP dependent protein kinase A (PKA) and Ca2+ calmodulin kinase pathways.
A PDE3 inhibitor is a drug which inhibits the action of the phosphodiesterase enzyme PDE3. They are used for the therapy of acute heart failure and cardiogenic shock.
8-OH-DPAT is a research chemical of the aminotetralin chemical class which was developed in the 1980s and has been widely used to study the function of the 5-HT1A receptor. It was one of the first major 5-HT1A receptor full agonists to be discovered.
Pilsicainide (INN) is an antiarrhythmic agent. It is marketed in Japan as サンリズム (Sunrythm). It was developed by Suntory Holdings Limited and first released in 1991. The JAN applies to the hydrochloride salt, pilsicainide hydrochloride.
Denopamine (INN) is a cardiotonic drug which acts as a β1 adrenergic receptor agonist. It is used in the treatment of angina and may also have potential uses in the treatment of congestive heart failure and for clearing pulmonary oedema. It is marketed in Japan under the brand name Kalgut (カルグート) and available as tablets of 5 and 10 mg, and 5% fine granules.
Vesnarinone (INN) is a cardiotonic agent. A mixed phosphodiesterase 3 inhibitor and ion-channel modifier that has modest, dose-dependent, positive inotropic activity, but minimal negative chronotropic activity. Vesnarinone improves ventricular performance most in patients with the worst degree of heart failure.
A phosphodiesterase-4 inhibitor, commonly referred to as a PDE4 inhibitor, is a drug used to block the degradative action of phosphodiesterase 4 (PDE4) on cyclic adenosine monophosphate (cAMP). It is a member of the larger family of PDE inhibitors. The PDE4 family of enzymes are the most prevalent PDE in immune cells. They are predominantly responsible for hydrolyzing cAMP within both immune cells and cells in the central nervous system.
Atiprosin is an antihypertensive agent which acts as a selective α1-adrenergic receptor antagonist. It also possesses some antihistamine activity, though it is some 15-fold weaker in this regard than as an alpha blocker. It was never marketed.
ICI-204,448 is a drug which acts as a potent and peripherally selective κ-opioid agonist, with possible uses in the treatment of heart attack as well as anti-itching effects. It is used in research to distinguish centrally from peripherally mediated kappa opioid receptor effects.
Indorenate (TR-3369), is a tryptamine derivative which acts as an agonist at the 5-HT1A, 5-HT1B and 5-HT2C serotonin receptors. It has anxiolytic, antihypertensive and anorectic effects, predominantly through action at 5-HT1A, but with some contribution from the 5-HT1B and 5-HT2C subtypes, and possibly some other non-serotonergic targets also.
AH-1058 is a lipophilic antiarrhythmic calcium channel blocker synthesized by the Pharmaceutical Research Laboratories of Ajinomoto Co., Inc in Kawasaki, Japan. It is derived from cyproheptadine, a compound with known antiserotonic, antihistaminic and calcium channel blocking properties. The IUPAC name of AH-1058 is: 4-(5H-dibenzo[a,d]cyclohepten-5-ylidene)-1-[E-3-(3-methoxy-2-nitro) phenyl-2-propenyl]piperidine hydrochloride.
Istaroxime is an investigational drug under development for treatment of acute decompensated heart failure
Phosphodiesterases (PDEs) are a superfamily of enzymes. This superfamily is further classified into 11 families, PDE1 - PDE11, on the basis of regulatory properties, amino acid sequences, substrate specificities, pharmacological properties and tissue distribution. Their function is to degrade intracellular second messengers such as cyclic adenine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP) which leads to several biological processes like effect on intracellular calcium level by the Ca2+ pathway.
