Dapsone is an antibacterial in the sulfone family of antibiotics. It is used to treat leprosy and the skin condition known as dermatitis herpetiformis. When treating leprosy, this medication is used along with other medications for at least 6 months. In some cases the medication may need to be taken for many more months or years.

Your doctor may have suggested this medication for conditions other than those listed in these drug information articles. As well, some forms of this medication may not be used for all of the conditions discussed here. If you have not discussed this with your doctor or are not sure why you are taking this medication, speak to your doctor. Do not stop taking this medication without consulting your doctor.

Do not give this medication to anyone else, even if they have the same symptoms as you do. It can be harmful for people to take this medication if their doctor has not prescribed it.

Leprosy: The recommended adult dose of dapsone when used for leprosy is 100 mg daily. For children, the dose should be adjusted according to body weight (1 mg to 2 mg per kilogram of body weight daily). Dapsone is used in combination with other medications.

Dermatitis herpetiformis: To treat dermatitis herpetiformis, the usual starting dose is 50 mg once daily, to be increased until an effective dose is reached. In some cases, up to 300 mg daily may be required.

Actinomycotic mycetoma: The recommended dose of dapsone is 100 mg taken 2 times a day. Treatment should be continued until the infection clears and then for several months later.

Many things can affect the dose of a medication that a person needs, such as body weight, other medical conditions, and other medications. If your doctor has recommended a dose different from the ones listed here, do not change the way that you are taking the medication without consulting your doctor.

The medication needs to be taken for several months after the symptoms have disappeared to prevent the condition from returning. It is important to take dapsone as directed for as long as it has been prescribed, even if you are feeling better.

The medication should be taken with a full glass of water, with or after food. Take it with food if stomach upset occurs.

It is important to take this medication exactly as prescribed by your doctor. If you miss a dose, take it as soon as possible and continue with your regular schedule. If it is almost time for your next dose, skip the missed dose and continue with your regular dosing schedule. Do not take a double dose to make up for a missed one. If you are not sure what to do after missing a dose, contact your doctor or pharmacist for advice.

Store this medication at room temperature, protect it from light, and keep it out of the reach of children.

Each white-to-off-white, round tablet debossed with "HP" on one side and scored on other side with  "9 | 9" , contains 100 mg of dapsone. Nonmedicinal ingredients: silica colloidal anhydrous, magnesium stearate, microcrystalline cellulose, and maize starch.

Dapsone should not be taken by anyone who:

• is allergic to dapsone or to any of the ingredients of the medication
• has a kidney problem called advanced amyloidosis of the kidneys

Many medications can cause side effects. A side effect is an unwanted response to a medication when it is taken in normal doses. Side effects can be mild or severe, temporary or permanent. The side effects listed below are not experienced by everyone who takes this medication. If you are concerned about side effects, discuss the risks and benefits of this medication with your doctor.

The following side effects have been reported by at least 1% of people taking this medication. Many of these side effects can be managed, and some may go away on their own over time.

Contact your doctor if you experience these side effects and they are severe or bothersome. Your pharmacist may be able to advise you on managing side effects.

• blurred vision
• dizziness
• fast heartbeat
• fatigue
• headache
• loss of appetite
• nausea or vomiting
• skin rash or itch
• trouble sleeping

Although most of these side effects listed below don't happen very often, they could lead to serious problems if you do not check with your doctor or seek medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

• easy bruising
• itching, dryness, redness, scaling, or peeling of the skin
• loss of hair
• numbing or tingling sensation in the hands or feet
• signs of depression (e.g., poor concentration, changes in weight, changes in sleep, decreased interest in activities)
• signs of infections (e.g., fever or chills, sore throat)
• signs of liver problems (e.g., nausea, vomiting, diarrhea, loss of appetite, weight loss, yellowing of the skin or whites of the eyes, dark urine, pale stools)
• unusual tiredness or weakness

Stop taking the medication and seek immediate medical attention if any of the following occur:

• severe skin reaction (e.g., blistering, peeling, a rash covering a large area of the body, a rash that spreads quickly, or a rash combined with fever or discomfort)
• signs of an allergic reaction (e.g., shortness of breath or difficulty breathing; hives; swelling of the eyes, mouth, lips, or throat)

Some people may experience side effects other than those listed. Check with your doctor if you notice any symptom that worries you while you are taking this medication.

Before you begin using a medication, be sure to inform your doctor of any medical conditions or allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use this medication.

Anemia: Dapsone is known to cause certain types of anemia (low levels of red blood cells). People with anemia should discuss with their doctor how this medication may affect their medical condition, how their medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed. You will need to have your blood counts checked routinely while taking this medication.

Dizziness/reduced alertness: Dapsone can cause dizziness for people who take normal doses. Do not drive, use machinery, or do any activity that requires alertness until you are sure that you can do these activities safely.

Glucose-6-phosphate dehydrogenase deficiency: People who lack the enzyme glucose-6-phosphate dehydrogenase should discuss with their doctor how this medication may affect their medical condition, how their medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Heart disease: People with heart disease should discuss with their doctor how this medication may affect their medical condition, how their medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Kidney disease: People with kidney disease should discuss with their doctor how this medication may affect their medical condition, how their medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed. You will probably need regular kidney tests while taking this medication to make sure that this medication is not harming your kidneys.

Liver disease: People with liver disease should discuss with their doctor how this medication may affect their medical condition, how their medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed. You will probably need regular liver tests while taking this medication to make sure that this medication is not harming your liver.

Lung disease: People with lung disease should discuss with their doctor how this medication may affect their medical condition, how their medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Pregnancy: This medication should not be used during pregnancy unless the benefits outweigh the risks. If you become pregnant while taking this medication, contact your doctor immediately.

Breast-feeding: This medication passes into breast milk. If you are a breast-feeding mother and are taking dapsone, it may affect your baby. Talk to your doctor about whether you should continue breast-feeding.

Children: This medication should not be used for children less than 1 month old.

There may be an interaction between dapsone and any of the following:

• azole antifungals (e.g., fluconazole, itraconazole, ketoconazole, voriconazole)
• chloroquine
• clarithromycin
• didanosine
• hydroxychloroquine
• mefloquine
• nicardipine
• primaquine
• probenecid
• proguanil
• protease inhibitors; anti-HIV medications (lopinavir, ritonavir, saquinavir)
• quinine
• rifabutin
• rifampin
• sulfisoxazole

If you are taking any of these medications, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:

• stop taking one of the medications,
• change one of the medications to another,
• change how you are taking one or both of the medications, or
• leave everything as is.

An interaction between two medications does not always mean that you must stop taking one of them. Speak to your doctor about how any drug interactions are being managed or should be managed.

Medications other than those listed above may interact with this medication. Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them.