WARNINGS
The patient should be warned to respond to the presence of
clinical signs such as sore throat, fever, pallor, purpura or jaundice. Deaths
associated with the administration of Dapsone have been reported from
agranulocytosis, aplastic anemia and other blood dyscrasias. Complete blood
counts should be done frequently in patients receiving Dapsone. The FDA
Dermatology Advisory Committee recommended that, when feasible, counts should be
done weekly for the first month, monthly for six months and semi-annually
thereafter. If a significant reduction in leucocytes, platelets or hemopoiesis
is noted, Dapsone should be discontinued and the patient followed intensively.
Folic acid antagonists have similar effects and may increase the incidence of
hematologic reactions; if co-administered with Dapsone the patient should be
monitored more frequently. Patients on weekly pyrimethamine and Dapsone have
developed agranulocytosis during the second and third month of therapy.
Severe anemia should be treated prior to initiation of therapy and hemoglobin
monitored. Hemolysis and methemoglobin may be poorly tolerated by patients with
severe cardiopulmonary disease.
Cutaneous reactions, especially bullous, include exfoliative dermatitis and
are probably one of the most serious, though rare, complications of sulfone
therapy. They are directly due to drug sensitization. Such reactions include
toxic erythema, erythema multiforme, toxic epidermal necrolysis, morbilliform
and scarlatiniform reactions, urticaria and erythema nodosum. If new or toxic
dermatologic reactions occur, sulfone therapy must be promptly discontinued and
appropriate therapy instituted. Leprosy reactional states, including cutaneous,
are not hypersensitivity reactions to Dapsone and do not require
discontinuation. See special section.
PRECAUTIONS
General: Hemolysis and Heinz body
formation may be exaggerated in individuals with a glucose-6-phosphate
dehydrogenase (G6PD) deficiency, or methemoglobin reductase deficiency, or
hemoglobin M. This reaction is frequently dose-related. Dapsone should be given
with caution to these patients or if the patient is exposed to other agents or
conditions such as infection or diabetic ketosis capable of producing hemolysis.
Drugs or chemicals which have produced significant hemolysis in G6PD or
methemoglobin reductase deficient patients include Dapsone, sulfanilamide,
nitrite, aniline, phenylhydrazine, napthalene, niridazole, nitro-furantoin and
8-amino-antimalarials such as primaquine.
Toxic hepatitis and cholestatic jaundice have been reported early in therapy.
Hyperbilirubinemia may occur more often in G6PD deficient patients. When
feasible, baseline and subsequent monitoring of liver function is recommended;
if abnormal, Dapsone should be discontinued until the source of the abnormality
is established.
PREGNANCY
Teratogenic Effects. Pregnancy Category C: Animal reproduction studies
have not been conducted with Dapsone. Extensive, but uncontrolled experience and
two published surveys on the use of Dapsone in pregnant women have not shown
that Dapsone increases the risk of fetal abnormalities if administered during
all trimesters of pregnancy or can affect reproduction capacity. Because of the
lack of animal studies or controlled human experience, Dapsone should be given
to a pregnant woman only if clearly needed. In general, for leprosy, USPHS at
Carville recommends maintenance of Dapsone. Dapsone has been important for the
management of some pregnant D.H. patients.
NURSING MOTHERS
Dapsone is excreted in breast milk in substantial amounts. Hemolytic reactions
can occur in neonates. See section on hemolysis. Because of the potential for
tumorgenicity shown for Dapsone in animal studies a decision should be made
whether to discontinue nursing or discontinue the drug taking into account the
importance of drug to the mother.
PEDIATRIC USE
Pediatric patients are treated on the same schedule as adults but with
correspondingly smaller doses. Dapsone is generally not considered to have an
effect on the later growth, development and functional development of the
pediatric patient.
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