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Ethambutol Hydrochloride  Audio icon

Other Names: EMB, Myambutol, ethambutol
Chemical Images:
ethambutol hydrochloride ethambutol hydrochloride
Molecular Weight: 277.233
ethambutol hydrochloride

What is ethambutol hydrochloride?


Ethambutol hydrochloride is an antibacterial prescription medicine approved by the U.S. Food and Drug Administration (FDA) for the treatment of active tuberculosis (TB) disease. Ethambutol hydrochloride is always used in combination with at least one other anti-TB medicine. Active TB disease is an opportunistic infection. An opportunistic infection is an infection that occurs more frequently or is more severe in people with weakened immune systems—such as those infected with HIV—than in people with healthy immune systems.

Ethambutol hydrochloride can also be used “off-label” to prevent and treat other opportunistic infections of HIV infection. “Off-label” use refers to use of an FDA-approved medicine in a manner different from that described on the medicine label. Good medical practice and the best interests of a patient sometimes require that a medicine be used “off-label.”


What HIV-related opportunistic infections is ethambutol hydrochloride used for?


The Guidelines for Prevention and Treatment of Opportunistic Infections in HIV-Infected Adults and Adolescents, prepared by the U.S. Department of Health and Human Services (HHS) and the Centers for Disease Control and Prevention (CDC), includes recommendations on the HIV-related uses of ethambutol hydrochloride to:

  • Prevent:
    • Disseminated Mycobacterium avium complex (MAC) disease from recurring (called secondary prophylaxis or maintenance therapy). (This is an “off-label” use.)
  • Treat:
    • Active TB disease.
    • Disseminated MAC disease. (This is an “off-label” use.)


What should I tell my health care provider before taking ethambutol hydrochloride?


Before taking ethambutol hydrochloride, tell your health care provider:

  • If you are allergic to ethambutol hydrochloride or any other medicines.
  • About any medical conditions you have or have had, for example, diabetes or liver problems.
  • About anything that could affect your ability to take medicines, such as difficulty swallowing or remembering to take pills.
  • If you are pregnant or plan to become pregnant. Whether ethambutol hydrochloride can harm an unborn baby is unknown.
  • If you are breastfeeding or plan to breastfeed. Do not breastfeed if you are infected with HIV.
  • About other prescription and nonprescription medicines, vitamins, nutritional supplements, and herbal products you are taking or plan to take. Ask your health care provider if there are interactions between ethambutol hydrochloride and the other medicines you take.

Ask your health care provider about possible side effects from ethambutol hydrochloride. Your health care provider will tell you what to do if you have side effects.


How should I take ethambutol hydrochloride?


Take ethambutol hydrochloride according to your health care provider’s instructions. Your health care provider will tell you how much ethambutol hydrochloride to take and when to take it. Before you start ethambutol hydrochloride and each time you get a refill, read any printed information that comes with your medicine.


How should ethambutol hydrochloride be stored?


  • Store ethambutol hydrochloride at room temperature, 68°F to 77°F (20°C to 25°C).
  • Protect from light and moisture.
  • Safely throw away ethambutol hydrochloride that is no longer needed or expired (out of date).
  • Keep ethambutol hydrochloride and all medicines out of reach of children.


Where can I find more information about ethambutol hydrochloride?


More information about ethambutol hydrochloride is available:


Last Reviewed: October 3, 2012

Last Updated: October 3, 2012