Name: Aczone

Dapsone Dosage

Oral dapsone comes as a tablet to take by mouth. It's typically taken once a day or three times a week.

It's best to take this medicine on an empty stomach, but it can be taken with food if you experience nausea otherwise.

Try to take oral dapsone around the same time each day.

Follow the instructions on your prescription label carefully when taking this medicine. Don't take more or less dapsone than is recommended.

Be sure to take oral dapsone for the full length of treatment. Don't stop using this medicine without first talking with your doctor.

Topical Aczone comes as a gel to apply to the skin.

Follow the instructions on your product label carefully when applying this medicine. Don't use more of the gel, or use it more often, than is recommended.

Before applying Aczone, wash the area to be treated and pat it dry.

Apply a pea-sized amount of Aczone gel to the affected area. Rub the gel in completely.

Wash your hands immediately after using the gel.

Avoid contact with the eyes and lip area when applying Aczone.

Dapsone Overdose

Symptoms of an oral dapsone overdose may include:

  • Nausea
  • Seizures
  • Vomiting
  • Bluish skin discoloration
  • Easy excitability

Topical dapsone may be harmful if swallowed.

If you suspect an overdose or accidentally swallow the topical medicine, contact a poison control center or emergency room immediately.

You can get in touch with a poison control center at 800-222-1222.

Missed Dose of Dapsone

If you miss a dose of dapsone, take it as soon as you remember.

But skip the missed dose if it's almost time for your next dose.

Don't double up on doses to make up for a missed one.

What special precautions should I follow?

Before using dapsone,

  • tell your doctor and pharmacist if you are allergic to dapsone, sulfonamide-derived medications ('sulfa drugs'), or any of the ingredients in dapsone gel. Ask your pharmacist for a list of the ingredients.
  • tell your doctor and pharmacist what other prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking or plan to take. Be sure to mention any of the following: acetaminophen; anticonvulsant medications such as phenytoin (Dilantin, Phenytek); antimalarial medications such as chloroquine (Aralen), primaquine, and quinine (Qualaquin); dapsone (by mouth); nitrofurantoin (Furadantin); nitroglycerin (Minitran, Nitro-Dur, Nitromist, others); phenobarbital; pyrimethamine (Daraprim); rifampin (Rifadin, Rimactane; in Rifamate, in Rifater); or sulfonamide-containing medications including co-trimoxazole (Bactrim, Septra). Your doctor may need to change the doses of your medications or monitor you carefully for side effects.
  • tell your doctor what herbal products you are taking, especially St. John's wort.
  • tell your doctor if you have or have ever had hemolytic anemia (a condition with an abnormally low number of red blood cells), glucose-6-phosphate dehydrogenase (G-6PD) deficiency (an inherited blood disorder), or methemoglobinemia (a condition with defective red blood cells that are unable to carry oxygen to the tissues in the body).
  • tell your doctor if you are pregnant, plan to become pregnant, or are breastfeeding. If you become pregnant while using dapsone, call your doctor. Tell your doctor if you are breast-feeding.
  • if you are having surgery, including dental surgery, tell the doctor or dentist that you are using dapsone.
  • tell your doctor if you use topical products containing benzoyl peroxide (in Duac, in Onexton; found in many topical acne products). Using benzoyl peroxide products with dapsone gel may cause your skin or facial hair to turn yellow or orange temporarily.

Indications and Usage for Aczone

Aczone® (dapsone) Gel, 7.5%, is indicated for the topical treatment of acne vulgaris in patients 12 years of age and older.



Aczone - Clinical Pharmacology

Mechanism of Action

The mechanism of action of dapsone gel in treating acne vulgaris is not known.


In a pharmacokinetic study, male and female subjects 16 years of age or older with acne vulgaris (N=19) received 2 grams of Aczone Gel, 7.5%, topically to the face, upper chest, upper back and shoulders once daily for 28 days. Steady state for dapsone was reached within 7 days of dosing. On Day 28, the mean dapsone maximum plasma concentration (Cmax) and area under the concentration-time curve from 0 to 24 hours post dose (AUC0-24h) were 13.0 ± 6.8 ng/mL and 282 ± 146 ng∙h/mL, respectively. The systemic exposure from Aczone Gel, 7.5% is expected to be about 1% of that from a 100 mg oral dose.

Long-term safety studies were not conducted with Aczone Gel, 7.5%, however, in a long-term clinical study of dapsone gel, 5% treatment (twice daily), periodic blood samples were collected up to 12 months to determine systemic exposure of dapsone and its metabolites in approximately 500 subjects. Based on the measurable dapsone concentrations from 408 subjects (M=192, F=216), obtained at Month 3, neither gender nor race appeared to affect the pharmacokinetics of dapsone. Similarly, dapsone exposures were approximately the same between the age groups of 12-15 years (N=155) and those greater than or equal to 16 years (N=253). There was no evidence of increasing systemic exposure to dapsone over the study year in these subjects.


In Vivo Activity: No microbiology or immunology studies were conducted during Aczone Gel, 7.5% clinical studies.

Drug Resistance: No dapsone resistance studies were conducted during dapsone gel clinical studies. Because no such studies were done, there are no data available as to whether dapsone treatment may have resulted in decreased susceptibility of Propionibacterium acnes, an organism associated with acne, or to other antimicrobials that may be used to treat acne. Therapeutic resistance to dapsone has been reported for Mycobacterium leprae, when patients have been treated with oral dapsone.

Nonclinical Toxicology

Carcinogenesis, Mutagenesis, Impairment of Fertility

Dapsone was not carcinogenic to rats when orally administered for a lifetime at dose levels up to 15 mg/kg/day (approximately 340 times the systemic exposure that is associated with the MRHD of Aczone Gel, 7.5%, based on AUC comparisons).

No evidence of potential to induce carcinogenicity was obtained in a dermal study in which dapsone gel was topically applied to Tg.AC transgenic mice for approximately 26 weeks. Dapsone concentrations of 3%, 5%, and 10% were evaluated; 3% material was judged to be the maximum tolerated dosage.

Topical gels that contained dapsone at concentrations up to 5% did not increase the rate of formation of ultraviolet light-induced skin tumors when topically applied to hairless mice in a 12-month photocarcinogenicity study.

Dapsone was not mutagenic in a bacterial reverse mutation assay (Ames test) using S. typhimurium and E. coli, with and without metabolic activation, and was negative in a micronucleus assay conducted in mice. Dapsone increased both numerical and structural aberrations in a chromosome aberration assay conducted with Chinese hamster ovary (CHO) cells.

The effects of dapsone on fertility and general reproduction performance were assessed in male and female rats following oral (gavage) dosing. Dapsone reduced sperm motility at dosages of 3 mg/kg/day or greater (approximately 22 times the systemic exposure that is associated with the MRHD of Aczone Gel, 7.5%, based on AUC comparisons). The mean numbers of embryo implantations and viable embryos were significantly reduced in untreated females mated with males that had been dosed at 12 mg/kg/day or greater (approximately 187 times the systemic exposure that is associated with the MRHD of Aczone Gel, 7.5%, based on AUC comparisons), presumably due to reduced numbers or effectiveness of sperm, indicating impairment of fertility. Dapsone had no effect on male fertility at dosages of 2 mg/kg/day or less (approximately 15 times the systemic exposure that is associated with the MRHD of Aczone Gel, 7.5%, based on AUC comparisons). When administered to female rats at a dosage of 75 mg/kg/day (approximately 1400 times the systemic exposure that is associated with the MRHD of Aczone Gel, 7.5%, based on AUC comparisons) for 15 days prior to mating and for 17 days thereafter, dapsone reduced the mean number of implantations, increased the mean early resorption rate, and reduced the mean litter size. These effects were probably secondary to maternal toxicity.

Dapsone was assessed for effects on perinatal/postnatal pup development and postnatal maternal behavior and function in a study in which dapsone was orally administered to female rats daily beginning on the seventh day of gestation and continuing until the twenty-seventh day postpartum. Maternal toxicity (decreased body weight and food consumption) and developmental effects (increase in stillborn pups and decreased pup weight) were seen at a dapsone dose of 30 mg/kg/day (approximately 560 times the systemic exposure that is associated with the MRHD of Aczone Gel, 7.5%, based on AUC comparisons). No effects were observed on the viability, physical development, behavior, learning ability, or reproductive function of surviving pups.

Adverse Effects


Dryness (16%)

Erythema (13%)


Burning (1%)

Pruritus (1%)

Postmarketing reports


What happens if I overdose?

An overdose of Aczone is not expected to be dangerous. Seek emergency medical attention or call the Poison Help line at 1-800-222-1222 if anyone has accidentally swallowed the medication.

Aczone side effects

Get emergency medical help if you have signs of an allergic reaction to Aczone: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Aczone may cause methemoglobinemia (met-HEEM-oh glo-bin-EE-mee-a), a serious condition in which the amount of oxygen in your blood stream becomes dangerously low. Stop using this medicine and call your doctor at once if you notice a blue or gray appearance of your lips, fingernails, or the inside of your mouth.

Call your doctor at once if you have:

  • severe sore throat;

  • unusual thoughts or behavior;

  • a red blood cell disorder - back pain, pale or yellowed skin, dark colored urine, fever, confusion or weakness;

  • pancreas problems - severe pain in your upper stomach spreading to your back, nausea and vomiting, fast heart rate; or

  • severe skin reaction - fever, sore throat, swelling in your face or tongue, burning in your eyes, skin pain followed by a red or purple skin rash that spreads (especially in the face or upper body) and causes blistering and peeling.

Common Aczone side effects may include:

  • dry or peeling skin;

  • oily skin; or

  • redness where the medicine was applied.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Dapsone Identification

Substance Name


CAS Registry Number


Drug Class

Antiinfective Agents

Leprostatic Agents