What diseases does Dapson treat?

Article written by Pharmacist Huynh Xuan Loc - Faculty of Pharmacy - Vinmec Central Park International General Hospital

Dapson is an antibacterial drug of the sulfon family that inhibits Hansen bacilli (Mycobacterium Leprae) causing leprosy. Discovered in 1908 by two German chemists, Eric Fromm and J. Wittmann, dapson was originally used in the textile industry. It was not until 1949 after many studies that Dapson was proven to be outstandingly effective in the treatment of leprosy and contributed greatly to ending this epidemic worldwide.
Today, dapsone is also used to treat other diseases such as Herpes Dermatitis, Pneumocystis jiroveci (P. carinii) pneumonia, Toxoplasmosis in HIV-infected people and even to prevent malaria in some cases.

Dapsone is in pill form and is taken as prescribed by a doctor. In the treatment of leprosy, the patient may need to take the drug for up to 6 months and then have an annual visit to detect recurrence.
Dapson is a prescription drug and moreover can cause many harmful effects if taken in excess or inappropriately. Therefore, patients are not allowed to self-medicate and must go to medical facilities for examination and treatment. Here, depending on the patient's condition, the doctor will consider the dose and monitor the patient's response to treatment.

Dapson can cause a variety of side effects but the most notable are hemolytic anemia and methemoglobin, which is common in patients taking 200mg or more per day. The drug may also cause hypersensitivity, skin rash, headache or nausea, vomiting, loss of appetite or insomnia. Rarely, the drug causes hematopoietic disorders, exfoliative dermatitis, more seriously toxic epidermal necrolysis or Steven-Johnson syndrome.
Patients should immediately stop dapsone if a toxic skin reaction occurs. Doctors may prescribe high doses of corticosteroids if an allergy or neuritis develops. Intravenous methylene blue is also used to treat methemoglobinemia.

Dapson is a specific treatment drug and is only used when prescribed by a doctor. Patients should note danger signs such as cyanosis, skin discoloration, difficulty breathing, headache, dizziness, fatigue, lightheadedness ... or skin symptoms such as rash, blisters, red skin , peeling ... It is necessary to stop the drug and immediately notify the treating doctor or visit a medical facility if you encounter the above conditions.
Patients need to tell the treating doctor if ever allergic to dapsone or other sulfa drugs.
Patients also need to alert their doctor if they are experiencing health problems such as anemia or G6PD (glucose-6-phosphate dehydrogenase) deficiency, are pregnant, nursing or suspect that they may be pregnant. .
Because dapsone has adverse interactions with many different drugs and active ingredients, the patient should tell the doctor all the drugs they are taking, including those without prescription (such as vitamins, minerals, etc.), herbs, and supplements. herbal medicine or other functional food.
While taking the drug, the patient should abstain from alcohol or other alcoholic beverages. Avoid prolonged exposure to the sun or cover up when outdoors to reduce the risk of skin burns due to increased photosensitivity.
Store the medicine according to the manufacturer's recommendations, usually it is necessary to keep the medicine in a cool place, away from sunlight or near a source of heat.

This drug requires a doctor's prescription, so you should go to a medical facility for examination and advice from specialist doctors. Vinmec International General Hospital is a high-quality medical facility in Vietnam with a team of highly qualified medical professionals, well-trained, domestic and foreign, and experienced.
A system of modern and advanced medical equipment, possessing many of the best machines in the world, helping to detect many difficult and dangerous diseases in a short time, supporting the diagnosis and treatment of doctors the most effective. The hospital space is designed according to 5-star hotel standards, giving patients comfort, friendliness and peace of mind.

References:
Vietnam National Pharmacopoeia, Dapson treatise, 2018 Justin Barr, A short history of dapsone, or an alternative model of drug development, J Hist Med Allied Sci, 2011