Ethambutol

Ethambutol.svg

Ethambutol is an antibiotic primarily used to treat tuberculosis. It is specifically effective against Mycobacterium tuberculosis, the bacterium responsible for tuberculosis. Ethambutol is often used in combination with other antituberculosis medications such as isoniazid, rifampicin, and pyrazinamide.

Medical Uses

Ethambutol is indicated for the treatment of active tuberculosis infections. It is not used as a monotherapy due to the rapid development of resistance. Instead, it is part of a multi-drug regimen to ensure the effectiveness of the treatment and to prevent the emergence of drug-resistant strains of Mycobacterium tuberculosis.

Mechanism of Action

Ethambutol works by inhibiting the enzyme arabinosyl transferase, which is involved in the polymerization of arabinogalactan, an essential component of the mycobacterial cell wall. This inhibition disrupts the cell wall synthesis, leading to the death of the bacteria.

Pharmacokinetics

Ethambutol is well absorbed from the gastrointestinal tract and reaches peak plasma concentrations within 2 to 4 hours after oral administration. It is widely distributed throughout the body, including the lungs, kidneys, and cerebrospinal fluid. The drug is primarily excreted unchanged in the urine.

Side Effects

Common side effects of ethambutol include gastrointestinal disturbances such as nausea and vomiting. A significant adverse effect is optic neuritis, which can lead to visual disturbances and, in severe cases, permanent vision loss. Regular monitoring of vision is recommended during treatment.

Contraindications

Ethambutol is contraindicated in patients with known hypersensitivity to the drug. Caution is advised in patients with pre-existing optic neuritis or other visual impairments.

History

Ethambutol was first synthesized in the 1960s and has since become a crucial component of the standard treatment regimen for tuberculosis. Its development marked a significant advancement in the fight against tuberculosis, particularly in the context of multi-drug therapy.

See Also

• Tuberculosis
• Antibiotics
• Isoniazid
• Rifampicin
• Pyrazinamide

External Links

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