Sulfonamides hemolytic anemia with

Genetic deficiency of glucose-6-phosphate dehydrogenase, with consequent impairment of the generation of NADPH, is common in populations of Mediterranean and Afro-Caribbean origin. The defect is manifested as red cell hemolysis (hemolytic anemia) when susceptible individuals are subjected to oxidants, such as the an-timalarial primaquine, aspirin, or sulfonamides or when... 

The answer is a. (Katzung, p 162.) Many drugs can cause an immunohemolytic anemia. Methyldopa may cause a positive Coombs test in as many as 20% of patients, along with hemolytic anemia. Other drugs with similar actions on red blood cells are penicillins, quinidine, procainamide, and sulfonamides. These form a stable or unstable hapten on the red cell surface, which induces an immune reaction I immunoglobulin G (IgG) antibodies] and leads to dissolution of the membrane. 

The answers are 484-k 485-j. (tlardman, pp 1061-1062, 1682-1685.) Sulfonamides can cause acute hemolytic anemia. In some patients it mayr be related to a sensitization phenomenon, and in other patients the hemolysis is due to a glucose-6-phosphate dehydrogenase deficiency Sulfamethoxazole alone or in combination with trimethoprim is used to treat UTls. The sulfonamide sulfasalazine is employed in the treatment of ulcerative colitis. Daps one, a drug that is used in the treatment of leprosy, and primaquine, an anti mala rial agent, can produce hemolysis, particularly in patients with a glucose-6-phosphate dehydrogenase deficiency. 

The thiazides are sulfonamides and share cross-reactivity with other members of this chemical group. Photosensitivity or generalized dermatitis occurs rarely. Serious allergic reactions are extremely rare but do include hemolytic anemia, thrombocytopenia, and acute necrotizing pancreatitis. 

Dapsone (Avlosulfon) is a member of a class of chemical agents known as the sulfones. Dapsone is especially effective against M. leprae and is used with rifampin as the primary method of treating leprosy. Dapsone appears to exert its antibacterial effects in a manner similar to that of the sulfonamide drugs that is, dapsone impairs folic acid synthesis by competing with PABA in bacterial cells. Primary adverse effects associated with dapsone include peripheral motor weakness, hypersensitivity reactions (skin rashes, itching), fever, and blood dyscrasias, such as hemolytic anemia. 

The problems encountered most frequently with sulfonamide drugs include gastrointestinal distress, increased skin sensitivity to ultraviolet light, and allergic reactions. Serious disturbances in the formed blood elements, including blood dyscrasias such as agranulocytosis and hemolytic anemia, may also occur during systemic sulfonamide therapy. 

The frequency and severity of the adverse effects of sulfonamides correspond to those seen with other antibacterial agents (2-5%). Dose-related effects, which tend to be more troublesome than serious, include gastrointestinal symptoms, headache, and drowsiness. Crystalluria can occur, but urinary obstruction is rare. Hematological adverse effects due to folic acid antagonism occur primarily in combination with trimethoprim. Hemolytic anemia occurs in patients with enzyme deficiencies and abnormal hemoglobins. Hypersensitivity... 

Sulfonamides have adverse effects on all bone marrow-derived cell lines. The resulting disturbances include hemolytic anemia, folate deficiency anemia, neutropenia, thrombocytopenia, and pancytopenia. While adverse effects on erythrocytes are rare, the rates of leukopenia, neutropenia, and thrombocytopenia are highly variable. In a hospital drug monitoring program, leukopenia or neutropenia occurred in 0.4% of 1809 patients treated with co-trimox-azole (54), and thrombocytopenia of mild-to-moderate degree in 0.1% (54,55), similar to figures recorded in other studies (56,57). Pancytopenia is an extremely rare form of adverse reaction to sulfonamides (58). 

Hemolytic anemia has been described for drugs containing sulfonamides, quinones, anilines, and carboxylic acids resulting from oxidative damage or covalent binding to red blood cells.42-49 NCEs with these functional groups should be carefully evaluated for reactive metabolite formation early in drug discovery. 

Many of the adverse reactions seen with sulfonamides are due to hypersensitivity reactions, which include dermatitis, leukopenia, hemolytic anemia, and drug fever. Stevens-Johnson syndrome is a very severe, but rare hypersensitivity reaction that occurs only with some of the long-acting sulfonamide preparations. 

Although rare, acute hemolytic anemia can occur. This may reflect an immune reaction or may be due to glucose-6-phosphate dehydrogenase deficiency. Agranulocytosis occurs in -0.1% of patients who receive sulfadiazine and also can occur with other sulfonamides. Although neutropenia may persist for weeks or months after sulfonamide is withdrawn, most patients recover spontaneously with supportive care. Pancytopenia with complete suppression of bone-marrow activity is extremely rare. It probably results from a direct myelotoxic effect and may be fatal. Reversible suppression of the bone marrow is quite common in patients with limited bone marrow reserve (e.g., patients with AIDS or those receiving myelosuppressive chemotherapy). 

Observational studies The safety of topical silver sulfadiazine has been reviewed and the adverse effects of the silver and sulfadiazine components discussed [182 ]. Allergic reactions with cross-sensitivity to antibiotic sulfonamides can occur, but there have been no reports of severe allergic reactions. Hemolytic anemia in G6PD-defi-cient patients can occur. Methemoglobinemia occurred in a 3-year-old child with bums and a dominant beta thalassemia trait treated with silver sulfadiazine. 

Sulfonamides can cause hemolytic or aplastic anemia, granulocytopenia, thrombocytopenia, or leukemoid reactions. Sulfonamides may provoke hemolytic reactions in patients with glucose-6-phosphate dehydrogenase deficiency. Sulfonamides taken near the end of pregnancy increase the risk of kernicterus in newborns. 

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