Acnesone Gel

Indications

Dapsone is available as a gel for the skin and as tablets. Dapsone gel (5% or 7.5%) is used to treat acne in people aged 12 years and older. Dapsone tablets are used, as prescribed, to treat leprosy (together with other medicines) and dermatitis herpetiformis (an itchy blistering skin condition linked to coeliac disease), and sometimes to prevent or treat Pneumocystis pneumonia and toxoplasmosis in people with weak immunity.

How It Works

Dapsone is a sulfone antibacterial. It blocks the way bacteria make folic acid, which stops their growth, and it also has anti inflammatory effects: it reduces the activity of white blood cells (neutrophils) that cause inflammation in the skin. In acne, the gel calms red, inflamed spots.

Dosage and Administration

Gel: wash and dry the skin, then apply a pea sized amount in a thin layer to the whole acne affected area, twice a day for the 5% gel or once a day for the 7.5% gel, or as directed by your doctor. Wash hands afterwards and avoid the eyes and mouth. If no improvement after 12 weeks, see your doctor. Tablets: take exactly as prescribed; the dose depends on the condition, and leprosy requires long courses with other medicines. Blood tests are needed during tablet treatment.

Interactions

Tablets: Rifampicin lowers Dapsone levels, while Trimethoprim and Probenecid can raise them and increase side effects. Avoid other medicines that can damage red blood cells or cause methaemoglobinaemia (such as Primaquine, Nitrofurantoin or local anaesthetics such as Benzocaine in large amounts). Gel: using it with Benzoyl Peroxide may temporarily turn skin or hair yellow or orange. Do not use other drying acne products on the same area without advice.

Contraindications

• Allergy to Dapsone or sulfone medicines.
• Tablets: severe anaemia, severe G6PD deficiency, porphyria, or a previous serious reaction to Dapsone.

Side Effects

Gel: dryness, redness, peeling, itching or oiliness of the skin where applied. Tablets: headache, nausea, loss of appetite, and a fall in haemoglobin (anaemia) or blue grey skin colour from methaemoglobinaemia (a change in blood that reduces oxygen delivery). Less often, it can cause liver problems, nerve damage or a serious allergic syndrome.

Get urgent medical help if you develop blue or grey lips or nails, breathlessness, unusual tiredness or paleness, dark urine, yellow skin or eyes, fever with sore throat, a widespread rash or blistering, or swollen glands, especially in the first weeks of tablet treatment (Dapsone hypersensitivity syndrome).

Pregnancy and Lactation

Tablets may be used in pregnancy for leprosy or dermatitis herpetiformis if the doctor decides it is needed, usually with folic acid. Dapsone passes into breast milk and can cause anaemia in some babies, especially those with G6PD deficiency or jaundice; ask your doctor. Use the gel in pregnancy or breastfeeding only if advised.

Precautions and Warnings

A G6PD test is recommended before starting tablets. Blood counts and liver tests are checked regularly during tablet treatment. Tell your doctor if you have heart or lung disease, anaemia or G6PD deficiency. Stop the gel and see a doctor if you notice signs of anaemia. Avoid strong sun if skin becomes sensitive. The gel is for external use only.

Overdose

Swallowing tablets in overdose can cause severe methaemoglobinaemia (blue skin, breathlessness, confusion), vomiting and blood problems. Seek emergency medical help immediately; specific treatment is available in hospital.

Therapeutic Class

Sulfone antibacterial and anti inflammatory agent; anti leprosy medicine; topical anti acne agent.

Storage

Store below 30°C in a dry place, away from light and out of the reach of children. Do not freeze the gel.