CHLORPHENIRAMINE

Mechanism of action for chlorpheniramine

• It binds to the H1 receptor. This blocks the action of endogenous histamine, which subsequently leads to temporary relief of the negative symptoms brought on by histamine.

Indication of chlorpheniramine

• Perennial and seasonal allergic rhinitis and other allergic symptoms including urticaria such as hay fever, urticaria, eczema, dermatitis, skin edema, itching due to insect bites, photo-dermatitis, and serum sickness. 

Dose required 

• Adult: 4mg TDS or qid (do not exceed 24mg / d * ay )
• Child: 0.35mg / k * g / d * ay in 4-5 divided dose.

Contraindication

• Alcoholic patient,
• Who taking CNS depressant drugs.

Side effects 

• Constipation
• Diarrhea,
• Dry mouth
• Sedation
• Dizziness
• Drowsiness
• Excitability
• Headache
• Loss of appetite
• Nausea
• Nervousness or anxiety
• Trouble sleeping
• Epigastric discomfort
• Urinary retention
• Vomiting, weakness
• Mood changes
• Tremor
•  Weakness
• Short of breath
• Constipation
• Blurred vision
• Paradoxical excitement

Nursing consideration

• It may cause drowsiness. Caution patient to avoid driving or other activities requiring alertness until response to medication is known.
• Oral dose should be given on an empty stomach for the fastest response.
• Subcutaneous/Intramuscular/Intraveno injection: The 100mg / m * l preparation is intended for IM or SC use only. It should not be administered IV because it contains preservatives. The 10 mg/ml injection can be given IV, IM, or SC.
• Monitor for sedation, especially when combined with other CNS depressants.
• Monitor blood pressure in hypertensive patients since chlorpheniramine may elevate blood pressure.
• Do not breastfeed while taking this drug.