Dr samiullah khalil Fcps (II) Trainee Dermatology
In the early 20th century, it is invented by the German chemist Paul Ehrlich while working on selective toxicity . Dapsone (diamino-diphenyl sulfone)is a medication most commonly usedin combination with rifampicin andclofazimine as multidrug therapy(MDT) for the treatment ofMycobacterium leprae infections (leprosy). Official in IP,BP,USP.
1. Absorption It is completely absorbed after oral administration2. Distribution Approximately 70% bound to plasma protein. The main metabolite, monoacetyl dapsone, is nearly 100% protein bound.
After oral administration the drug is mainly eliminated by kidney.20 percent is excreted unchanged while 80 percent as derivatives. Only minor amount is excreted in faeces . Bile: 10% of an oral dose was found in the bile Breast-milk: Dapsone is excreted in breast milk
Plasma concentration of Dapsone is reduced by Rafampicin. Plasma concentration of both drugs may increase when Dapsone given with Trimethoprim. This medication may decrease the effectiveness of combination- type birth control pills.This can result in pregnancy.
Mycobacterium leprae infections (leprosy)./hansen’s disease Linear Ig A Bullous disease Acne. Vasculitis Sweet syndrome Mycetoma
DISEASE ADULT CHILDREN DAYS Leprosy - Lepromatous 50-100 mg/day 6-10 mg/day 2-5 years Leprosy - Tuberculoid 100 mg/day NA 6 months Dermatitis Herpetiformis 50-300 mg/day NA Life long basis Pneumocystis Pneumonia 100 mg/day 2 mg/kg/day 14-21 days Pneumocystis Pneumonia 100 mg/day 2 mg/kg/day Life long basis ProphylaxisToxoplasmosis - Prophylaxis 100 mg/day 2 mg/kg/day Life long basis
TRANSDERMAL DOSE Administered transdermally As a gel 5% topical acne medication available in 3-, 30-, and 60-gram tubes. In normal use, 0.5 grams should be administered to the face per application twice a day.
Mild haemolytic anaemia (decreases with use of Vit C or Vit E ). Gastric intolerance-nausea & anorexia Methaemoglobinaemia (treated with Cemitidine) , headache, paresthesias, mental symptoms & drug fever allergic rashes, fixed drug eruption, hypermelanosis, phototoxicity& rarely exfoliative dermatitis, steven Jhonsen syndrome. Hepatitis & agranulocytosis
Uncommonly weakness of the feet and hands muscles with dose greater then 100 mg/day It is tested by ability to walk on toes tip and to test Hand grip. Leucopenia presents with fever ,sore throat ,skin infections and other common infections. Bluish discoloration of lips and finger tips Dapsone reaction/sulfone syndrome
Hypersensitivity more frequent in patients receiving multiple-drug therapy. The reaction involves a rash and may also include fever, jaundice, and eosinophilia. Swollen lymph glands and internal organ failure (Liver , Lungs , Heart and Kidney). In general, these symptoms will occur within the first six weeks of therapy or not at all, and may be treated by corticosteroid therapy.
Allergic to sulphur containing antibiotics G6PD deficiency Heart diseases Lung diseases Breast feeding Pregnancy Porphyria
FBC before the start of the therapy Then at 1 week Then once monthly