Dapsone is a medication that belongs to a group of sulfone antibiotics and is used in leprosy. It can be used alone or in combination with other medications. Apart from leprosy even some other skin conditions such as dermatitis herpetiformis can be treated with dapsone.
Side Effects of Dapsone
Hematologic Side Effects
Blood disturbance are the most common side effects of dapsone. Methemoglobulinemia, aplastic anemia, leukopenia and agranulocytosis are rather serious medical conditions caused by this medication. Eosinophilia, macrocytic anemia and formation of Heinz bodies may additionally develop. Hemolytic anemia can be caused by higher doses and in those patients who have been suffering from glucose-6-phosphate dehydrogenase deficiency. Pure red cell aplasia has been reported only once.
Agranulocytosis develops usually a few months after the treatment has begun. Methemoglobinemia may be fatal in all those patients who have already suffered from heart conditions or respiratory insufficiency. Cyanosis or the blue coloration of the lips and fingertips may point to the onset of hypoxia. Increased degree of methemoglobulinemia leads to headache and muscle weakness followed by dyspnea.
Aplastic anemia may develop in small number of cases and it usually affects patients between the 2nd and the 12th week of the therapy.
Nervous System Side Effects
Peripheral neuropathy is a common neurological side effects of dapsone. Motor deficit is expressed more than sensory loss. The function of the nerves re-establishes without any consequence after discontinuation of dapsone. Peripheral neuropathy most commonly affects the hands.
Additional neurologic side effects may include lightheadedness, vertigo, and headache.
Gastrointestinal Side Effects
Dapsone may lead to nausea, vomiting and pain in the abdomen.
Hepatic Side Effects
Elevation in liver enzymes is one of the regular side effects of dapsone. In rather rare cases one may develop hepatitis or cholestatic jaundice. Increased level of bilirubin has also been reported. This side effect is mainly present in people suffering from glucose-6-phosphate dehydrogenase deficiency.
Respiratory Side Effects
Pulmonary eosinophilia has been reported in two patients.
Immunologic Side Effects
This medication can cause a relapse of systemic lupus erythematosus and the first outbreak of this autoimmune disease.
Psychiatric Side Effects
Some people who have been using dapsone developed depression, hypomania and psychosis.
This side effect has been reported mainly in HIV positive patients. Rash, Steven-Johnson syndrome, toxic erithema, erithema multiforme, toxic epidermal necrolysis, morbiliform or scarlatiniform reactions are some of the serious side effects that can occur due to usage of dapsone. There have also been a few cases of sulfone syndrome and renal hypersensitivity vasculitis.
Renal Side Effects
Dapsone may induce nephritic syndrome and papillary necrosis.
Other Side Effects
So called dapsone syndrome is a side effect which features with increased body temperature, chills, main in muscles and joints, exanthema, enlarged lymph nodes, and lymphocytosis. Apart from these flu-like symptoms liver is enlarged and functional liver test shows increase in liver enzymes. Even anemia and methemoglobulinemia are present in dapsone syndrome.
As a result of successful therapy there are two states that may develop. The first one includes reversal reaction and the second one features with erythema nodosum leprosum. These reactions to the treatment may require hospitalization but the treatment is continued in majority of patients with the assistance of symptomatic therapy including analgesics or corticosteroids.