April 22, 2024

Acetazolamide: A Potent Carbonic Anhydrase Inhibitor

This drug has been widely used since the 1950s and remains an important therapeutic option even today. Let’s take a deeper look at acetazolamide, how it works, its uses and side effects.

How does Acetazolamide Work?

Acetazolamide is considered a potent inhibitor of the carbonic anhydrase enzyme. Carbonic anhydrase plays a key role in various physiological processes in the human body by catalyzing the reversible hydration of carbon dioxide. It is present in high concentrations in red blood cells, lungs, kidneys, stomach, pancreas, and other tissues.

By inhibiting carbonic anhydrase, acetazolamide decreases the formation of bicarbonate ions as well as protons in various tissues like the eye, kidneys, and central nervous system. This lowers the production of aqueous humor in the eye, reduces renal bicarbonate reclamation and urine formation in the kidneys, and alters acid-base balance in the brain and cerebrospinal fluid. These actions underlie its therapeutic benefits for conditions like glaucoma, epilepsy, and altitude sickness.

Uses of Acetazolamide

Glaucoma: Acetazolamide is commonly prescribed as an adjunct treatment for open-angle glaucoma and ocular hypertension. By decreasing aqueous humor secretion, it helps lower intraocular pressure and maintain the pressure within the normal range. This helps prevent further optic nerve damage in patients with glaucoma.

Epilepsy: For certain seizure disorders like infantile spasms and refractory epilepsy, Acetazolamide is used to alter the acid-base balance in the brain and raise the seizure threshold. This makes seizures less frequent and easier to control.

Altitude Sickness: Also known as acute mountain sickness, this condition affects lowland residents who rapidly ascend to high altitudes over 8,000 feet. Acetazolamide reduces AMAS symptoms by stimulating respiratory drive and enhancing acclimatization. It allows hikers and climbers to acclimatize faster at higher elevations.

Congenital Central Alkalosis: This rare inherited condition is caused by mutations affecting chloride-bicarbonate exchange in the kidneys. Acetazolamide helps correct the metabolic alkalosis by reducing bicarbonate reabsorption in the kidneys’ distal convoluted tubules.

Others uses include treatment of idiopathic intracranial hypertension, periodic paralysis, renal calculi, and ophthalmic cystathionine. It is also occasionally prescribed off-label for migraine prophylaxis.

Potential Side Effects of Acetazolamide

Like all drugs, acetazolamide too can cause certain side effects especially when starting or increasing the dose. Common ones include:

– Gastrointestinal disturbances like nausea, vomiting, heartburn, loss of appetite

– Paresthesia (tingling sensation) in hands and feet

– Fatigue and weakness

– Metabolic acidosis at high doses

– Potential sulfonamide allergy in susceptible individuals

– Nephrolithiasis or kidney stone formation due to carbonic anhydrase inhibition

– Polyuria (excessive urination) due to effects on renal tubules

– Electrolyte disturbances like hyponatremia and hypokalemia

– Myopia or nearsightedness in rare cases

Therefore, doctors closely monitor patients for any side effects and adjust treatment accordingly. Most adverse reactions are mild to moderate in intensity and diminish over time as the body adjusts to the drug. However, patients should report severe or persistent symptoms to the physician promptly.

Acetazolamide remains a very useful drug for selected ophthalmic, neurological, and altitude-related conditions where carbonic anhydrase inhibition proves beneficial. As a potent diuretic, it impacts acid-base and electrolyte balance hence needs monitoring during therapy. Overall, acetazolamide offers an effective treatment option when prescribed and monitored judiciously by healthcare experts for appropriate patients.

1. Source: Coherent Market Insights, Public sources, Desk research
2. We have leveraged AI tools to mine information and compile it