Mechanism of Action-

Paracetamol has a spectrum of action similar to that of NSAIDs and resembles particularly the COX-2 selective inhibitors. Paracetamol is a weaker analgesic than NSAIDs or COX-2 selective inhibitors but is often preferred as it is better tolerated. Being similar to NSAIDs, the mode of action of paracetamol has been uncertain, but it is now generally accepted that it inhibits COX-1 and COX-2 through metabolism by the peroxidase function of these isoenzymes. This leads to inhibition of phenoxyl radical synthesis from a critical tyrosine residue essential for the cyclooxygenase activity of COX-1 and COX-2 and prostaglandin (PG) synthesis.
Phenylephrine is categorized as sympathomimetic drug and mimics the actions of epinephrine (commonly known as adrenaline) or norepinephrine. Phenylephrine selectively binds to alpha-1 receptors which cause blood vessels to constrict leads to nasal decongestant action.
Levocetirizine selectively inhibits the H1 receptor and prevents the release of histamine which causes smooth muscle contraction, increase vascular permeability, stimulation of cough. All this acitivities is blocked by levocetirizine.

Pharmacokinetics:

Paracetamol is rapidly absorbed from the GIT, bioavailability being dose-dependent and ranging from 70 to 90%.The volume of distribution of approximately 0.9L/kg. Paracetamol is extensively metabolised predominantly in the liver, the major metabolites being the sulphate and glucuronide conjugates. 85 to 95% of a therapeutic dose is excreted in the urine within 24 hours.
Phenylephrine: When orally administered, the bioavailability was found to be 38%. Peak concentration reaches between 0.5 and 2 hours after administration. No protein‐binding data in humans are available. It undergoes extensive biotransformation in the gut wall and the liver. Half‐lives is relatively short, approximately 2.5 hours. Reduced metabolism of Phenylephrine occurs with concurrent administration of monoamine oxidase inhibitors.
Levocetirizine is well orally absorbed and is highly bound to plasma proteins. It is poorly metabolized, but undergoes O-dealkylation and glucuronide conjugation. The half-life of levocetrizine is 8-9 hours.

Common side effect of the product includes:

• Palpitations
• Headache
• Dizziness
• Nausea
• Anxiety
• Restlessness
• Weakness
• Insomnia

Do not use this combination in the following conditions:

• Caloric undernutrition.
• Severe renal impairment.
• A condition where the body is unable to maintain adequate blood flow called shock.
• Acetaminophen overdose.
• Acute inflammation of the liver due to hepatitis C virus.

• Taking the following syrup with alcohol can cause liver damage
• Consuming the following syrup along with any other sedative medication may cause excessive drowsiness.
• The drug is generally safe to use while driving. However, if you feel dizziness or drowsiness, driving is not recommended
• Should also be avoided by people with hypersensitivity.
• Formulation is not safe for people with renal diseases or renal failure. Get doctor’s advice in case of renal-related disorders.