- Cough and cold, Allergic rhinitis
Mechanism of Action
Phenylephrine is a sympathomimetic amine that acts predominantly on α-adrenergic receptors. It is mainly used to treat nasal congestion;.It causes vasoconstriction in the mucosa of the respiratory tract leads to decreased oedema and increased drainage of sinus cavities, hence providing relief from stuffy nose and sinus pressure.
Dextromethorphan which is an antitussive (cough suppressant) and provides temporary relief of cough ,It acts on the cough centre in medulla of the brain.
- Should be used in caution with patients with gastric ulcer.
- Use cautiously with pregnancy, lactation, and persistent coughs.
- Use drug with caution in patients with cirrhosis or other liver disease.
- It should not be used in patients hypersensitive to any active ingredient.
- It should not be used in patients severe hypertension, ventricular tachycardia,
Warning & Precautions
- Monitor patient for dizziness and excessive drowsiness. If noted, hold therapy and notify health care provider.
- Use with caution in elderly patients, usually starting at the low end of the dosage range because of the greater frequency of decreased hepatic, renal, or cardiac function, and concomitant diseases or other drug therapy.
Monoamine oxidase inhibitors may increase the anti cholinergic effects of Chlorpheniramine.
Allergic reactions such as skin rash, nettle-rash, and angioneurotic oedema are possible. Under the prolonged administration in large doses pain in epigastrial area, nausea, vomiting can appear
Patients using the following medicines should use dextromethorphan with caution, celecoxib, imatinib , quinidine, ranolazine, ritonavir, sibutramine, terbinafine.
- Drowsiness due to Chlorpheniramine, sedation ; slow, shallow breathing.
Overdosage may induce ventricular extrasystoles and short paroxysms of ventricular tachycardia, a sensation of fullness in the head and tingling of the extremities.
Should an excessive elevation of blood pressure occur, it may be immediately relieved by an α– adrenergic blocking agent (e.g., phentolamine).Blurred vision, confusion, difficulty in urination, drowsiness or dizziness, nausea or vomiting (severe), shakiness and unsteady walk, slowed breathing, unusual excitement, nervousness, restlessness, or irritability
Pharmacodynamics:The combination is well established in patients with cold and cough.
Chlorpheniramine Maleate:Absorption and distribution: It is absorbed relatively slowly from the gastrointestinal tract, with peak plasma concentrations occurring about 2.5 to 6 hours after oral administration. Chlorpheniramine appears to undergo considerable first-pass metabolism. Bioavailability is low, values of 25 to 50% having been reported. About 70% of chlorpheniramine in the circulation is bound to plasma proteins. There is wide inter-individual variation in the pharmacokinetics of chlorpheniramine; half-life values ranging from 2 to 43 hours have been reported. Chlorpheniramine is widely distributed in the body and enters the CNS.
Metabolism: Chlorpheniramine maleate is metabolised extensively. Metabolites include desmethyl- and didesmethylchlorpheniramine. Unchanged drug and metabolites are excreted primarily in the urine; excretion is dependent on urinary pH and flow rate. Only trace amounts have been found in the faeces.
Excretion: A duration of action of 4 to 6 hours has been reported; this is shorter than may be predicted from pharmacokinetic parameters.
Phenyleprine Maleate:Oral absorption of Phenylephrine (HCl) is found to be 73% ±2. Volume of distribution is found to be 340 litre . Presystemic metabolism is noted to be 60% and metabolism is reported Hepatic. Renal Excretion accounts for < 20 % and plasma half life is 2 - 3 hr.
Dextromethorphan hydrogen bromide:Dextromethorphan is rapidly absorbed from the gastrointestinal tract and peak plasma concentrations are reached in approximately 2.5 hours. Dextromethorphan is widely distributed, and is rapidly and extensively metabolized by the liver. Dextromethorphan is demethylated to dextrorphan, an active metabolite, and to 3-methoxymorphinan and 3-hydroxymorphinan. It is primarily excreted as unchanged parent drug and dextrorphan.
The preparation should not be used after the expiry date.
Keep it out of reach of children