Ethambutol (Myambutol)

Category:

  • Miscellaneous

Description:

  • Antituberculosis agent

Indications:

  • Adjunct in treatment of pulmonary tuberculosis

  • Mycobacterium avium complex (MAC) in AIDS (2nd line) (non-FDA approved)

Contraindications:

  • Optic neuritis

  • Child <13 years

Precautions:

  • Pregnancy category B; compatible with breast feeding

  • Renal disease diabetic retinopathy

  • Cataracts, ocular defects, hepatic and hematopoietic disorders, gout

Adverse Reactions (Side Effects):

  • CNS: confusion, disorientation, dizziness, fever, hallucinations, headache, malaise

  • EENT: bloody sputum, blurred vision, changes in color perception, decreased visual acuity, optic neuritis, photophobia

  • GI: abdominal distress, anorexia, nausea, vomiting

  • HEME: thrombocytopenia

  • METAB: acute gout, elevated uric acid, liver function impairment

  • MS: joint pain

  • SKIN: dermatitis, pruritis

 

Dosage:

Administered orally

  • Adult and Child >13 years: Tuberculosis: Initial treatment: PO 15 mg/kg/day as a single daily dose; Retreatment: PO 25 mg/kg/day as a single dose for 2 months with at least 1 other drug, then decrease to 15 mg/kg/day as single daily dose.

  • Mycobacterium avium complex in AIDS: PO 15 mg/kg with 3 or 4 other antimycobacterial agents

Special considerations:

  • Initial therapy in tuberculosis should include 4 drugs; isoniazid, rifampin, pyrazinamide, and ethambutol, until drug susceptibility results available

  • Administer with meals to decrease GI symptoms

    

 
Back to Medical Corps Pharmacy Page