Guaifenesine

Guaifenesine, commonly spelled guaifenesin, is an expectorant used to relieve chest congestion associated with upper respiratory tract infections, bronchitis, and other conditions that produce thick mucus. It is widely available in over‑the‑counter cough and cold products, either alone or in combination with decongestants, antihistamines, or cough suppressants.

The proposed action of guaifenesine is to increase the hydration and volume of secretions in the airways, which helps thin mucus and promotes productive coughing. The precise mechanism is not fully understood, but it is believed to stimulate the airway glands and facilitate mucus clearance rather than suppressing coughing.

Administration and pharmacology details are typical of oral medications: guaifenesine is taken by mouth in tablet, caplet, or syrup form. Dosing depends on the specific product and the patient’s age; patients should follow the directions on the label or those provided by a healthcare professional. After ingestion, guaifenesine is absorbed from the gastrointestinal tract and is metabolized in the liver, with metabolites excreted primarily in the urine.

Safety and regulatory status: guaifenesine is generally well tolerated. Common side effects are mild and may include nausea, vomiting, or dizziness. Allergic reactions are rare but possible. It is not a substitute for medical advice in cases of persistent cough, high fever, chest pain, or coughing that lasts several weeks; such symptoms warrant evaluation by a clinician. It is available OTC in many countries and is not subject to controlled-substance regulation in most jurisdictions.

See also: expectorants, mucolytics.