To the Editor:\p=m-\Acetazolamide(Diamox), a sulfonamide and a potent carbonic anhydrase inhibitor, is used in the control of fluid secretion and in the promotion of diuresis in cases of fluid retention. Adverse reactions to sulfonamides are well known, however, a brief review of the literature revealed only two previously reported cases of bone marrow depression due to acetazolamide, one with recovery,1 and one fatal.2 To these is added one of severe, fatal bone marrow depression with leukopenia, thrombocytopenia, and anemia after 3 1/2 months of treatment for glaucoma with 500 mg twice daily.Report of a Case:\p=m-\A66-year-old man was hospitalized because of severe pharyngitis, stomatitis, and cheilitis which had an onset approximately five days prior to hospitalization and had not responded to treatment with lincomycin and penicillin. The patient had been well prior to this except for recent onset of weakness, fatigue, mild dyspnea, and anorexia. There was no history of hemoptysis, hematemesis, melena, or hematuria. In February of 1969 he had been hospitalized for nar¬ row angle glaucoma bilaterally for which a peripheral iridectomy on the right had been done, and the patient had been discharged on a regimen of pilocarpine 2% mixture (Isopto Carpine), ophthalmic drops, for the left eye and acetazolamide, 500 mg morn¬ ing and evening. In February 1969, the hemoglobin level was 13.9 gm/100 cc and the white blood cell count (WBC) was 7,400/cu mm. The patient took the prescribed medication regularly until the time of readmission to the hos¬ pital on June 17.Physical examination at the time of admission revealed a dehydrated, very lethargic, ill-appearing man having a blood pressure of 128/86, and a regular pulse rate of 88 beats per minute. Tem¬ perature was 102 F (38.9 C) rectally. The skin had a yellow tinge and was dry and free of petechiae. A few ecchymotic areas were present in the skin of both forearms secondary to venapunctures. The lips were dry with bleeding fissures at both corners. The pharynx was red, swollen, and a puru¬ lent exúdate was present over the left tonsil. The mucous membranes were dry and the tongue was coated by brown material. The lungs were clear, and the heart rate was 96 beats per minute with a normal rhythm. The abdomen was slightly distended and tender. The liver and spleen were not enlarged. Lymph nodes were not enlarged.At the time of admission, the WBC was 1.000/cu mm, with 70% lympho¬ cytes. No immature red or white cells were present. The hemoglobin value was 12 gm/100 cc. Platelets were de¬ creased on the peripheral blood smear. After hydration, the WBC was 400/cu mm, and the hemoglobin level was 9.7 gm/100 cc. The platelet count was 5,000/cu mm, and a reticulocyte count was 0.1%. Laboratory studies revealed the following values: serum bilirubin, 3.1 mg/100 cc (2.9 mg conjugated, 0.2 mg unconjugated) ; alkaline phospha¬ tase, 6.5 KA units; thymol, 1.2 units; total protein, 6.0 gm/100 cc; serum glutamic oxaloacetic transaminase, 18 Karmen units; blood urea nitrogen, 45 mg/100 c...