Isosorbide is a heterocyclic compound

Heterocyclic compound

A heterocyclic compound is a cyclic compound which has atoms of at least two different elements as members of its ring. The counterparts of heterocyclic compounds are homocyclic compounds, the rings of which are made of a single element....

 derived from glucose

Glucose

Glucose is a simple sugar and an important carbohydrate in biology. Cells use it as the primary source of energy and a metabolic intermediate...

 and is thus a biofeedstock. Glucose can be hydrogenated to sorbitol

Sorbitol

Sorbitol, also known as glucitol, Sorbogem® and Sorbo®, is a sugar alcohol that the human body metabolizes slowly. It can be obtained by reduction of glucose, changing the aldehyde group to a hydroxyl group. Sorbitol is found in apples, pears, peaches, and prunes...

, which upon double dehydration

Dehydration

In physiology and medicine, dehydration is defined as the excessive loss of body fluid. It is literally the removal of water from an object; however, in physiological terms, it entails a deficiency of fluid within an organism...

 gives isosorbide.

Isosorbide is a used as a diuretic

Diuretic

A diuretic provides a means of forced diuresis which elevates the rate of urination. There are several categories of diuretics. All diuretics increase the excretion of water from bodies, although each class does so in a distinct way.- Medical uses :...

 used mainly to treat hydrocephalus

Hydrocephalus

Hydrocephalus , also known as "water in the brain," is a medical condition in which there is an abnormal accumulation of cerebrospinal fluid in the ventricles, or cavities, of the brain. This may cause increased intracranial pressure inside the skull and progressive enlargement of the head,...

 and is also used to treat glaucoma

Glaucoma

Glaucoma is an eye disorder in which the optic nerve suffers damage, permanently damaging vision in the affected eye and progressing to complete blindness if untreated. It is often, but not always, associated with increased pressure of the fluid in the eye...

.

Other medications are derived from isosorbide, including isosorbide dinitrate

Isosorbide dinitrate

Isosorbide dinitrate is a nitrate used pharmacologically as a vasodilator, e.g. in angina pectoris but also for anal fissure, a condition which is known to involve decreased blood supply leading to poor healing...

 and isosorbide mononitrate, are used to treat angina pectoris. Other isosorbide-based medicines are used as osmotic diuretic

Diuretic

A diuretic provides a means of forced diuresis which elevates the rate of urination. There are several categories of diuretics. All diuretics increase the excretion of water from bodies, although each class does so in a distinct way.- Medical uses :...

s and for treatment of esophageal varices. Like other nitric oxide

Nitric oxide

Nitric oxide, also known as nitrogen monoxide, is a diatomic molecule with chemical formula NO. It is a free radical and is an important intermediate in the chemical industry...

 donors (see biological functions of nitric oxide

Biological functions of nitric oxide

The gas nitric oxide plays a wide variety of roles in biological organisms.-Nitric oxide synthesis:Nitric oxide synthases synthesize the metastable free radical nitric oxide . There are three isoforms of the NOS enzyme: endothelial , neuronal , and inducible - each with separate functions...

), these drugs lower portal pressure by vasodilation

Vasodilation

Vasodilation refers to the widening of blood vessels resulting from relaxation of smooth muscle cells within the vessel walls, particularly in the large arteries, smaller arterioles and large veins. The process is essentially the opposite of vasoconstriction, or the narrowing of blood vessels. When...

 and decreasing cardiac output. Isosorbide dinitrate and hydralazine

Hydralazine

Hydralazine is a direct-acting smooth muscle relaxant used to treat hypertension by acting as a vasodilator primarily in arteries and arterioles...

 are the two components of the anti-hypertensive drug bidil.