Correspondence
Case 23-1999: Infantile Pulmonary Tuberculosis
N Engl J Med 1999; 341:1857-1858December 9, 1999
- Article
To the Editor:
In the July 29 Case Record,1 a 10-month-old infant with pulmonary tuberculosis was discharged while receiving antituberculous treatment that included ethambutol. The use of ethambutol in a patient of this age is fraught with danger.
Retrobulbar optic neuritis is the most serious adverse effect of ethambutol. Axial or central neuritis — the only form reported in patients taking ethambutol in daily doses of less than 30 mg per kilogram of body weight — involves the papillomacular bundle of fibers and results in reduced visual acuity, central scotoma, and loss of the ability to see green. Symptoms of ocular toxicity typically develop several months after the initiation of therapy, but rapid onset of optic neuritis has been reported.
The risk of optic neuritis depends on the dose and duration of therapy; this reaction develops in 5 percent of patients receiving a daily dose of 25 mg per kilogram but in fewer than 1 percent of patients given a daily dose of 15 mg per kilogram. Patients should be tested monthly (and whenever there is a subjective visual change) for visual acuity and for red–green color discrimination. Optic neuritis with associated visual loss is usually reversible, but recovery may take six months or longer.2
The drug is not recommended for young children, in whom visual complications are difficult to monitor.2
2 ReferencesAjit Singh Kashyap, M.D.
Surekha Kashyap, M.D.
Armed Forces Medical College, Pune 411040, India1
Case Records of the Massachusetts General Hospital (Case 23-1999)
Full Text | Web of Science | Medline2
Wright PW, Wallace RJ Jr. Mycobacterial diseases. In: Fauci AS, Martïn JB, Braunwald E, et al., eds. Harrison's principles of internal medicine. 14th ed. Vol. 1. New York: McGraw-Hill, 1998:997-1003.
Author/Editor Response
Dr. Pasternack replies:
To the Editor: The need for initial multidrug antituberculous chemotherapy is well established in the current era of possible drug-resistant tuberculosis. The potential ocular toxicity of ethambutol, summarized by Drs. Kashyap and Kashyap, is well known. The use of ethambutol in a four-drug initial treatment regimen is generally limited to eight weeks, at which time therapy can often be simplified on the basis of the results of drug-susceptibility tests. The incidence of optic neuritis (which is generally reversible) is extremely low when ethambutol is used for such a limited time at recommended doses.
Although ethambutol is not recommended for routine use in children younger than eight years of age, “it is used frequently and safely in children with life-threatening forms of tuberculosis or with drug-resistant tuberculosis,” as noted by Starke and Smith,1 and can be considered for use in all children with drug-resistant infection.2 In fact, the recommendations of the British Thoracic Society for the use of ethambutol in children are the same as for its use in adults.3 The inconvenience, discomfort, and potential ototoxicity of streptomycin all raise barriers to its routine inclusion in initial antituberculous chemotherapy. The father of the child discussed in Case 23-1999 was not willing to discuss his tuberculosis status or past therapy openly, and our concern regarding drug-resistant disease was great. Ethambutol was selected as an agent in the initial four-drug regimen on the basis of these considerations.
3 ReferencesMark S. Pasternack, M.D.
Massachusetts General Hospital, Charlestown, MA 02129-20001
Starke JR, Smith MHD. Tuberculosis. In: Feigin RD, Cherry JD, eds. Textbook of pediatric infectious diseases. 4th ed. Vol. 1. Philadelphia: W.B. Saunders, 1998:1196-239.
2
Bass JB Jr ,Farer LS ,Hopewell PC , et al. Treatment of tuberculosis and tuberculosis infection in adults and children. Am J Respir Crit Care Med 1994;149:1359-1374
Web of Science | Medline3
Joint Tuberculosis Committee of the British Thoracic Society
CrossRef | Web of Science | Medline
