Dapson

Dapson DOMINA  (TABLETS)

COMPOSITION: 
Each tablet contains 100mg Dapsone.

MECHANISM OF ACTION:
Dapsone has a wide spectrum activity against bacteria. But Dapsone is mainly used for its action against mycobacterium leprae. Dapsone is also used for treatment of Malaria. Dapsone is effective against plasmodium. Its mechanism is similar to that of sulphonamides, as it is also effective against p- amino benzoic acid.

INDICATIONS:
Dapsone is usually used as a principal medication for treatment of all cases of leprosy and dermatitis herpetiformis, and for prophylaxis of leprosy in persons in contact with leprosy patients.

DOSAGE:

  • In leprosy: 1-2 mg/Kg daily, i.e. 50-100mg daily. But treatment needs several years. In case of using low doses, resistant strains may develop. Therefore, it is necessary to maintain the dose.
  • In dermatitis herpetiformis: Dose is variable among individuals, it is 50mg daily. It could be increased gradually until it reaches 300 mg daily. Such dose should be reduced to the possible minimum to get satisfactory results. It may be 50mg weekly or 300mg daily.

SIDE EFFECTS:
Most of side effects are dose related, and are uncommon at low doses of 100mg where the drug is well tolerated. Side effects are: anorexia, dizziness, rash, tachycardia, nervousness, insomnia, eosinophillia, mononucleosis, leucopenia, jaundice with hepatitis. These symptoms are more common when increasing the dose of Dapsone or when the drug is used with other drugs for prophylaxis of Malaria. Haemolysis and methaemoglobinaemia occur usually with a dose of 200mg daily. Dose of 100mg daily does not usually cause haemolysis unless the patient is suffering from deficiency of glucose -6- phosphate dehydrogenase. In such case dose should not exceed 50mg daily. Those patients should be preformed regular blood count during treatment.

CONTRAINDICATIONS:
It should not be used in patients with cardiac or pulmonary or anemia diseases.

DRUG INTERACTIONS:
Dapsone is antagonized by p-amino benzoic acid. Probencid minimizes renal excretion of the drug and its serum concentration increases. Rifampicin increases renal clearance of the drug. Charcoal may increase the clearance of drug and stop its absorbance.The drug increases the trimethoprim concentration.

USE IN PREGNANCY OR LACTATION:
Treatment of leprosy with the drug in pregnancy is better than the risk of non-treatment. The drug is excreted in breast milk.

ABSORPTION AND ELIMINATION:
Dapsone is almost completely absorbed from gastrointestinal tract with peak plasma concentration occurring from 1 - 8 hrs after dose. Steady concentrations are obtained after 8 days of treatment. The plasma half- life ranges from 10- 50 hrs (average 28 hrs). About 50 - 80% of Dapsone is bound to plasma proteins. 70 - 85% of the dose is excreted in the urine of which about 20% is unchanged, and small amounts are found in feces.

PRESENTATION: 
Carton pack containing 2 blisters of 10 tablets in each, and a leaflet

 

 

 
 
 

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