Sinu-C Mechanism of Action

Pharmacology: Paracetamol: The 2 major actions of Paracetamol are: Relieve pain by inhibiting prostaglandin synthesis in the central nervous system and blocking peripheral pain impulse generation; Reduce fever by acting on the hypothalamic heat-regulating centre to produce increased blood flow through skin, sweating and thus help in heat dissipation.
Paracetamol is rapidly and completely absorbed following oral administration and will exert its effect between 30 minutes to 2 hours later. This effect could last for 3 to 4 hours. 85% to 90% of the administered dose is eliminated in the urine within 24 hours of ingestion.
Pseudoephedrine HCl: Pseudoephedrine HCl is a sympathomimetic used for the relief of nasal and bronchial congestion. It acts directly on α-adrenergic receptors in the respiratory tract mucosa producing vasoconstriction resulting in the shrinkage of swollen nasal mucous membrane, reduction of tissue hyperaemia, oedema, and nasal congestion thus an increase in nasal airway patency. Drainage of sinus secretions is increased and obstructed Eustachian ostia may be opened. Relaxation of bronchial smooth muscle by stimulation of b-adrenergic receptors may also occur.
Pseudoephedrine is readily absorbed from the gastrointestinal tract. It is largely excreted unchanged in the urine together with small amounts of its hepatic metabolite. Elimination is enhanced and half-life accordingly shorter in acidic urine.
Chlorpheniramine Maleate: Chlorpheniramine Maleate is a member of the alkyl amine group of antihistamines (H1 receptor antagonist). It does not block the release of histamine but acts by competitively antagonising the effects of histamine at H1 receptor sites. If the histamine concentration at the receptor sites exceeds the drug concentration, histamine release causes allergic reactions; therefore it is used for the symptomatic relief of allergic conditions.
Chlorpheniramine is absorbed relatively slowly from the gastrointestinal tract, peak plasma concentrations occurring about 2.5 to 6 hours after administration by mouth. Chlorpheniramine appears to undergo considerable first-pass metabolism. It is extensively metabolised. Metabolites include desmethyl- and didesmethylchlorpheniramine. Unchanged drug and metabolites are excreted primarily in urine; excretion is dependent on urinary pH and flow rate. Only trace amounts have been found in the faeces. A duration of action of 4 to 6 hours has been reported.