Rexotril syrup is a combination of phenylephrine hydrochloride ,chlorpheniramine maleate and mefenamic acid.
Phenylephrine hydrochloride belongs to phenethylamine class, a selective α1-adrenergic receptor agonist. It is mainly used as decongestant. It decreases the heart rate through reflex bradycardia.
Chlorpheniramine maleate is a first generation alkylamine antihistamine. It is used in the prevention of symptoms of allergic conditions such as rhinitis and urticaria.
It is a non steroidal anti-inflammatory drug which is mainly used in the treatment of pain.
Reduces symptoms associated with upper respiratory tract allergies
Relieves sneezing, running nose and watery eyes
Adjunct with antibiotic in sinusitis, tonsillitis and otitis media
5 to 10 ml of syrup every 3 to 6 h.
It acts on three types of α1 adrenergic receptor and these receptors are involved in maintenance of vascular tone which includes vasocontrictory effects. Its activation causes mobilization of Ca2+ from intracellular stores. Phenylephrine hydrochloride produces its action by action on peripheral vascular smooth muscle and decreases nasal congestion which leads to decreased edema and causes increase in drainage of sinus cavities.
It produces its action by binding to histamine H1 receptor which blocks the action of endogenous histamine which produces relief in symptoms associated with histamine.
After oral administration it is completely absorbed, the drugs bioavailability is affected due to first pass metabolism.
Nearly about 95% of the drug is bound to plasma protein. The drug is metabolized by liver. The peak serum concentration of the drug is achieving in 0.75-2hrs.
The elimination half life of the drug is 2.1 to 3.4 hours.
After oral administration the drug is well absorbed in GI tract
About 72% of the drug is bound to plasma protein. The drug follows hepatic metabolism.
The elimination half life of the drug is 21-27 hours.
Hypersensitivity reaction to any of the ingredient of the product
Severe coronary artery disease
Narrow-angle glaucoma; urinary retention
MAOI therapy or for 2 week after stopping MAOI therapy
Newborn or premature infants
Assess for allergy symptoms
Check the patient for nervousness, dizziness, and insomnia
Monitor children for antihistamine-induced excitability