Ethambutol was widely used in the treatment of tuberculosis. Side effects other than ocular toxicity are rare.
Incidence
Cutaneous reactions: 0.5%.
Drug fever: 0.3%.
Clinical manifestations
General: fever.
Cutaneous: pruritus, maculoerythematous rash, toxic epidermal necrolysis, purpura.
Respiratory: dyspnea, pulmonary infiltrates.
Haematological: eosinophilia, neutropenia, thrombocytopenia.
Diagnostic methods
Drug re-challenge is usually positive in the cases of fever or maculopapular rash.
Mechanisms
Unknown.
Management
Desensitization if absolutely necessary: 0.1 mg; 0.5 mg; 1 mg; 2 mg; 4 mg; 8 mg ; 16 mg; 32 mg; 50 mg; 100 mg; 200 mg at 45 minutes intervals; then 400 mg 3H30 later; then 400 mg x 3 the next day.