Mystacin Tablet

Indication:

Mystacin Tablet is indicated for the treatment of-

• Symptomatic Relief of Allergy: Hay fever, urticaria (hives), and angioedema.
• Allergic Reactions: Food allergies, drug reactions, and insect bites/stings.
• Emergency Treatment: Adjunct in the emergency management of anaphylactic shock (usually administered via injection).
• Common Cold: Relief of runny nose and sneezing (often found in combined cough/cold preparations).
• Pruritus: Itching associated with chickenpox or other skin conditions.

Dogase & Adminstration:

• Adults and Adolescents (>12 years):
  • Oral: 4 mg every 4–6 hours. Maximum 24 mg daily.
• Children (Oral – Based on BNFC):
  • 1–2 years: 1 mg twice daily.
  • 2–6 years: 1 mg every 4–6 hours. Maximum 6 mg daily.
  • 6–12 years: 2 mg every 4–6 hours. Maximum 12 mg daily.
• Elderly: More susceptible to anticholinergic side effects; dosage should be cautious (max 12 mg daily in some cases).
• Administration: Can be taken with or without food. If it causes stomach upset, take it with food or milk.

”রেজিস্ট্রার চিকিৎসকের পরামর্শ অনুযায়ী ঔষধ সেবন করুন”

Pharmacology:

• Mechanism of Action: Chlorphenamine acts as a competitive H1-receptor antagonist. It binds to H1 receptors on effector cells in the GI tract, blood vessels, and respiratory tract. This prevents histamine from binding, thereby inhibiting histamine-induced vasodilation, increased capillary permeability, and smooth muscle constriction.
• Pharmacodynamics: Besides its antihistaminic effect, it possesses significant anticholinergic activity (blocking acetylcholine receptors) and central sedative effects. It crosses the blood-brain barrier easily, leading to its well-known side effect of drowsiness.
• Pharmacokinetics: It is well absorbed from the GI tract. Peak plasma concentrations are reached in 2–3 hours. It is 70% protein-bound and undergoes significant metabolism in the liver. It is excreted mainly in the urine.

Side Effects:

• Very Common: Drowsiness, sedation, and dry mouth.
• Others: Blurred vision, urinary retention, gastrointestinal disturbances, and thickened respiratory secretions.

Drug Interaction:

• Alcohol & Sedatives: Greatly increases drowsiness and CNS depression.
• MAOIs (Antidepressants): May prolong and intensify the anticholinergic effects of chlorphenamine.
• Phenytoin: May inhibit the metabolism of phenytoin, leading to toxicity.

Pregnancy & Lactation:

• Pregnancy: Not known to be harmful, but use only when necessary, especially in the third trimester (risk of reactions in newborns).
• Lactation: Small amounts pass into breast milk. May inhibit lactation and cause drowsiness in the infant.

Over Dosage:

Symptoms: Ataxia, excitement, hallucinations, tremors, and in severe cases, convulsions or coma. Management is supportive.

Therapeutic Class:

Sedating Antihistamine; H1-receptor antagonist.

Storage Conditions:

Store below at 30°C  temperature in a dry place. Away from light and out of reach of children. Do not use the medication after its expiration date.