Drug reference
Tuberculosis, in combination with other drugs (standard unsupervised 6-month treatment) ▶BY MOUTH ▶Child: 20 mg/kg once daily for 2 months (initial phase) ▶Adult: 15 mg/kg once daily for 2 months (initial phase) Tuberculosis, in combination with other drugs (intermittent supervised 6-month treatment) (under expert supervision) ▶BY MOUTH ▶Child: 30 mg/kg 3 times a week for 2 months (initial phase) ▶Adult: 30 mg/kg 3 times a week for 2 months (initial phase)
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Optic neuritis. poor vision
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Elderly. young children CAUTIONS, FURTHER INFORMATION ▶Understanding warnings Patients who cannot understand warnings about visual side-effects should, if possible, be given an alternative drug. In particular, ethambutol should be used with caution in children until they are at least 5 years old and capable of reporting symptomatic visual changes accurately.
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The RCPCH and NPPG recommend that, when a liquid special of ethambutol is required, the following strength is used: 400 mg/5 mL.
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→Appendix 1: ethambutol
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▶Common or very common Hyperuricaemia. nerve disorders . visual impairment ▶Rare or very rare Nephritis tubulointerstitial ▶Frequency not known Alveolitis allergic. appetite decreased. asthenia. confusion. dizziness. eosinophilia. fever. flatulence. gastrointestinal discomfort. gout. hallucination. headache. jaundice. leucopenia. nausea. nephrotoxicity. neutropenia. photosensitive lichenoid eruption. sensation abnormal. severe cutaneous adverse reactions (SCARs). skin reactions. taste metallic. thrombocytopenia. tremor. vomiting SIDE-EFFECTS, FURTHER INFORMATION Ocular toxicity is more common where excessive dosage is used or if the patient’s renal function is impaired. Early discontinuation of the drug is almost always followed by recovery of eyesight.
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Not known to be harmful.
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Amount too small to be harmful.
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Risk of optic nerve damage. Should preferably be avoided in patients with renal impairment. Dose adjustments ▶In adults If creatinine clearance less than 30 mL/minute, use 15–25 mg/kg (max. 2.5 g) 3 times a week. ▶In children If creatinine clearance less than 30 mL/minute/1.73 m2, use 15–25 mg/kg (max. 2.5 g) 3 times a week. Monitoring If creatinine clearance less than 30 mL/minute, monitor plasma-ethambutol concentration.
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▶‘Peak’ concentration (2–2.5 hours after dose) should be 2–6 mg/litre (7–22 micromol/litre); ‘trough’ (pre-dose) concentration should be less than 1 mg/litre (4 micromol/litre). ▶Renal function should be checked before treatment. ▶Visual acuity should be tested by Snellen chart before treatment with ethambutol. ▶In children In young children, routine ophthalmological monitoring recommended.
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There can be variation in the licensing of different medicines containing the same drug. Forms available from special-order manufacturers include: oral suspension, oral solution Tablet CAUTIONARY AND ADVISORY LABELS 8 ▶Ethambutol hydrochloride (Non-proprietary) Ethambutol hydrochloride 100 mg Ethambutol 100mg tablets | 56 tablet P £17.00 DT = £11.51 Ethambutol hydrochloride 400 mg Ethambutol 400mg tablets | 56 tablet P £42.74 DT = £42.74 Combinations available: Rifampicin with ethambutol, isoniazid and pyrazinamide, p. 617
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Ocular toxicity The earliest features of ocular toxicity are subjective and patients should be advised to discontinue therapy immediately if they develop deterioration in vision and promptly seek further advice. Medicines for Children leaflet: Ethambutol for the treatment of tuberculosis www.medicinesforchildren.org.uk/ethambutol- treatment-tuberculosis
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15 mg/kg once daily for 2 months (initial phase)
First-line fragment. Read the complete Indications and Dose section above.
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30 mg/kg 3 times a week for 2 months (initial
First-line fragment. Read the complete Indications and Dose section above.
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