Dapsone: A Cure for Leprosy

Leprosy, a millennia old disease found throughout the world, is truly devastating, tearing apart families and communities. Caused by Mycobacterium leprae, leprosy affects the skin and peripheral nerves, slowly over the course of many years causing irreversible damage, in many cases leaving its victim with loss of feeling of limbs and skin lesions and heavily deformed. Over the ages, fear of the diseases has lead communities around the world, to forcefully disband countless victims from their ranks. Family-less, and outcasts, they turned to the only place where they were now accepted, with the other victims, forming what became known as Leper Colonies. However with incredibly few willing to come within any proximity to those effected, let alone offering help to those believed to have been cursed by god, lepers were forced to suffer the gruesome, tragic fate of struggling to make it by in isolation. In as early as 1200 AD there were as many as 19,000 leprosy cases in Europe alone, a number that only grew over time, swelling well into the millions in the nineteenth century.

In 1873 however the cause of the once mysterious, believed hereditary disease was discovered by pathologist Dr Gerhard A Hansen, a Norwegian pathologist, the bacteria Mycobacterium leprae. Even so, armed with this new-found knowledge, the prospect of finding a cure remained bleak, the International Leprosy Conference in 1897 itself, coming to the consensus that the disease was "incurable". The identification of the cause of this disease nevertheless resulted in a flurry of action to come-up this desperately needed cure. In the early twenty century the oil from the Chaulmoogra nut was proposed as one possible solution however worked with very limited success. Without any alternatives though, this treatment remained until in 1941 the sulfone drug Promin, was developed and used with effectiveness. It did however require multiple painful injection daily and so when in Diamino Diphenyl Sulphone (DDS) or Dapsone pills became available in the early 1950’s, an oral antibiotic proven to kill M. leprae, it became the leading treatment.

However by the time dapsone was officially approved by the Food and Drug Administration on July 3, 1979, in the form oral 25 and 100mg tables, dapsone resistant M. leprae had already began to appear. To combat this new strain of bacteria, dapsone doses began being taken with the weaker, more recently developed antibiotics rifampicin and clofazimine to effectively inhibit the spread of disease. Dapsone, absorbed through the gastrointestinal tract, achieves its effectiveness through inhibiting the production of Folinic acid, a chemical essential in the production of DNA, without which M. leprae cannot reproduce. Clofazimine and Rifampicin work through similar prosses to Dapsone, clofazimine through interfering with the bacteria's production of DNA and the latter through inhibiting the bacterial synthesis of RNA.