Efamed/Efamed Plus Mechanism of Action

Efamed tablet/syrup: Pharmacologic Classification: Antiasthma.
Pharmacology: Pharmacokinetics: Salbutamol is readily absorbed from the gastrointestinal tract. When given by inhalation, 10 to 20% of the dose reaches the lower airways. The remainder is retained in the delivery system or is swallowed and absorbed from the gut. Salbutamol is subject to first pass metabolism in the liver and possibly in the gut wall but does not appear to be metabolized in the lung; the main metabolite is the inactive sulfate conjugate. Salbutamol is rapidly excreted mainly in the urine, as metabolites and unchanged drug; a smaller proportion is excreted in the feces. The plasma half-life of salbutamol has been estimated to range from 4 to 6 hours.
Efamed solution for nebulization: Pharmacologic Classification: Bronchodilator.
Pharmacology: Pharmacokinetics: Salbutamol is readily absorbed from the gastro intestinal tract. When given by inhalation, 10-20% of the dose reaches the lower airways. The remainder is retained in the delivery in the delivery system or is swallowed and absorbed from the gut. Salbutamol is subject to first-pass metabolism in the liver and possibly in the gut wall but does not appear to be metabolized in the lungs; the main metabolite is the inactive sulfate conjugate. Salbutamol is rapidly excreted, mainly in the urine, as metabolites and unchanged drug: a smaller proportions excreted in the faeces. The plasma half-life of salbutamol has been estimated to range from 4-6 hours.
Efamed Plus tablet/syrup: Pharmacologic Classification: Expectorant/Bronchodilator.
Pharmacology: Pharmacodynamics: Mechanism of Action: Salbutamol is a selective β₂-adrenoceptor agonist. At therapeutic doses, it acts on the β₂-adrenoceptors of bronchial muscle, with little or no action on the β₁-adrenoceptors of cardiac muscle.
Guaifenesin can make the viscous mucus of the respiratory pathway more fluid and therefore expectoration and reduces cough.
Pharmacodynamic Effects: Salbutamol is a selective β₂-adrenoceptor agonist. At therapeutic doses it acts on the β₂-adrenoceptors of bronchial muscle providing short-acting (4-6 hours) bronchodilation in reversible airways obstruction.
Pharmacokinetics: Absorption: After oral administration, salbutamol is absorbed from the gastrointestinal tract and undergoes considerable first-pass metabolism to the phenolic sulfate. Both unchanged drug and conjugate are excreted primarily in the urine. Guaifenesin is well-absorbed after oral administration. After the administration of guaifenesin 600 mg in healthy adult volunteers the maximum peak plasma concentration (C_max) was approximately 1.4 mcg/mL with T_max about 15 minutes after drug administration.
Distribution: The bioavailability of orally administered salbutamol is about 50%. Salbutamol is bound to plasma proteins to the extent of 10%.
Metabolism: Salbutamol administered IV has a half-life (t_1/2) of 4-6 hours and is cleared partly renally and partly by metabolism to the inactive 4'-O-sulfate (phenolic sulfate) which is also excreted primarily in the urine. Guaifenesin has a plasma t_1/2 of approximately 1 hour and was not detectable in the blood after 8 hrs. Guaifenesin appears to undergo both oxidation and demethylation.
Elimination: The majority of a dose of salbutamol given IV, orally or by inhalation is excreted within 72 hrs. The feces are a minor route of excretion. Guaifenesin is excreted in urine.