Dapsone 100 mg Tablets

Brand name

The drug is known under the trade name Dapsone. This is the registered name under which the drug is presented in pharmacies and medical institutions all over the world.

International Nonproprietary Name (INN)

The international nonproprietary name of this medicine is dapsone. It indicates the main active substance that provides the therapeutic effect.

Form of release

The drug is available mainly in solid oral form for ease of use. The main form:

• Tablets with dosages of 25 mg, 50 mg and 100 mg of the active substance.

Alternatives such as powder for preparing a solution may be available in some countries, but are less common. The tablet form remains the most popular due to its ease of dosing and storage.

Composition

The main active ingredient is dapsone (diaminodiphenylsulfone), which has antibacterial and anti-inflammatory properties. The excipients in the tablets include:

• Microcrystalline cellulose - a filler that provides structure to the tablet.
• Pregelatinized starch - binder for mass formation.
• Magnesium stearate - a lubricating component that facilitates the manufacturing process.
• Lactose - auxiliary filler that improves consistency.
• Colloidal silicon dioxide - stabilizer, preventing caking.

The exact composition may vary depending on the manufacturer, but the ingredients listed are standard for most variants.

Pharmacologic Properties

Pharmacodynamics

The drug has a dual mechanism of action, which makes it unique in the therapy of certain diseases. It exhibits antibacterial activity by inhibiting the synthesis of folic acid in bacterial cells through competitive inhibition of the enzyme dihydropteroate synthetase. This process disrupts the multiplication of microorganisms such as Mycobacterium leprae, which is particularly important in the treatment of lepra. In addition, the drug demonstrates anti-inflammatory properties by reducing neutrophil activity and the production of reactive oxygen species, which is useful in autoimmune and dermatologic conditions.

The spectrum of action includes not only bacteria but also some protozoa. Efficacy is manifested with prolonged use, which requires strict adherence to the prescribed course of treatment.

Pharmacokinetics

Pharmacokinetic parameters provide stable accumulation and distribution of the active substance in the body.

Absorption

After oral administration, the active substance is absorbed in the gastrointestinal tract, reaching maximum concentration in blood plasma in 2-8 hours. Bioavailability is about 70-90%, which depends on the individual characteristics of the patient and conditions of administration. Food may slow down the absorption process, but does not significantly affect the overall efficacy.

Distribution

The active ingredient penetrates well into various tissues including skin, lung, liver and kidney. Binding to plasma proteins reaches 70-90%, with a significant portion bound to albumin. The ability to penetrate tissues makes the drug particularly valuable in the treatment of skin and systemic infections.

Metabolism

Metabolism occurs predominantly in the liver by acetylation and hydroxylation. Active metabolites are formed, such as monoacetyldapsone, which retains therapeutic activity and has a longer half-life. The rate of acetylation depends on the genetic characteristics of the patient (fast or slow acetylators).

Excretion

The drug is excreted via the kidneys, partly unchanged (20-30%) and partly as metabolites. The elimination half-life varies from 10 to 50 hours, averaging about 28 hours. Prolonged excretion allows maintaining a stable concentration when taken once a day.

Indications for Use

The medicine is used for the treatment of a number of specific diseases where antibacterial or anti-inflammatory action is required:

• Lepra (Hansen's disease) - as part of combination therapy with other antileprosy agents.
• Herpetiform dermatitis (Dühring's disease) - for suppression of inflammatory processes on the skin.
• Pneumocystis pneumonia (caused by Pneumocystis jirovecii) - as an alternative remedy in patients with intolerance to other drugs.
• Autoimmune dermatoses such as pemphigoid or linear IgA dermatopathy.
• Prevention of infections in immunodeficient patients (in some cases).

Prescribing is carried out only by a physician after careful diagnosis and evaluation of the sensitivity of the pathogen.

Contraindications

The use of the medicine is prohibited in the following cases:

• Individual intolerance to the active substance or auxiliary components.
• Severe anemia not associated with the underlying disease to be treated.
• Deficiency of glucose-6-phosphate dehydrogenase (risk of hemolysis).
• A history of acute porphyria.
• Severe hepatic or renal dysfunction without possibility of dose adjustment.

With caution prescribe in blood diseases, allergic reactions in the past or bronchial asthma.

Method of Administration and Dosage

How to take

The tablets are taken orally, drinking enough water (150-200 ml). It is recommended to consume them during or after meals to reduce the likelihood of irritation of the gastric mucosa. The tablet should not be chewed or crushed unless directed by a physician.

Dosages for adults and children

Dosage is determined by the nature of the disease and the age of the patient:

• Adults with leprosy: the initial dose - 50-100 mg once a day in combination with other means, the duration of the course is determined by the doctor (may be years).
• Adults with dermatitis herpetiformis: 50 mg per day with a gradual increase to 300 mg if necessary, then reducing to a maintenance dose.
• Children older than 1 month: 1-2 mg/kg of body weight per day, the maximum dose - 100 mg per day.

The exact treatment regimen is adjusted depending on the response to therapy and tolerability.

Dose adjustment for certain conditions

If renal or hepatic dysfunction requires individual adjustment:

• Creatinine clearance 15-30 mL/min: dose reduction by 50%.
• Clearance less than 15 ml/min: use only under medical supervision with consideration of hemodialysis.
• Hepatic insufficiency: dose reduction by 25-50% with monitoring of hepatic parameters.

Side Effects

Drug administration may be accompanied by adverse reactions:

• Hematological: hemolytic anemia, methemoglobinemia, leukopenia.
• Gastrointestinal: nausea, vomiting, decreased appetite, pain in the epigastrium.
• Skin: rash, photosensitivity, rarely - toxic epidermal necrolysis.
• Nervous: headache, dizziness, peripheral neuropathy.
• hepatic: increase in transaminases, jaundice (rare).

If severe symptoms occur, discontinue use and seek counseling.

Overdose

Symptoms of overdose

Overdose is manifested by cyanosis (due to methemoglobinemia), nausea, vomiting, confusion, dyspnea, tachycardia.

First aid measures

If an overdose is suspected:

• Stop taking the tablets.
• Rinse stomach (if less than 1-2 hours have passed).
• Inject methylene blue (if methemoglobinemia) under medical supervision.
• Provide plenty of water and symptomatic therapy.

Drug Interactions

Influence on the effects of other drugs

The drug may alter the effect of other drugs:

• Folic acid: decrease in its effectiveness.
• Antidiabetic drugs (sulfonylurea): increase in hypoglycemia.
• Rifampicin: acceleration of metabolism of the active substance.

Compatibility with alcohol and food

Alcohol increases the toxic effects on the liver and should be avoided. Food has no significant effect, but fatty foods may slow absorption.

Special Precautions

Use in pregnancy and breastfeeding

Application during pregnancy is possible only if absolutely necessary, since the active substance penetrates through the placenta. During lactation the drug is excreted with milk, which requires discontinuation of feeding for the duration of therapy.

Effects on driving and mechanisms

Dizziness and weakness may make it difficult to drive a car or operate machinery, especially at the beginning of treatment.

Particularities of use in the elderly and children

Hematologic complications occur more often in elderly patients, control of blood tests is required. In children, the drug is used with caution, starting with minimal doses.