Oral Decongestants for Nasal Congestion

Introduction to Oral Decongestants

The American Academy of Allergy, Asthma, and Immunology recommends pseudoephedrine and phenylephrine as the main types of oral decongestants for treating nasal congestion, with pseudoephedrine being significantly more effective due to better oral bioavailability compared to phenylephrine, which is extensively metabolized in the gut 1, 2

Pseudoephedrine functions as an α-adrenergic agonist that reduces nasal congestion by causing vasoconstriction in the nasal passages, available in immediate-release (30-60 mg every 4-6 hours) and extended-release formulations 3, 4
The American Heart Association notes that pseudoephedrine is associated with small increases in systolic blood pressure (0.99 mmHg) and heart rate (2.83 beats/min) but generally no significant effect on diastolic blood pressure 2, 5
The American Academy of Pediatrics advises that pseudoephedrine should be used with caution in patients with hypertension, arrhythmias, angina pectoris, coronary artery disease, cerebrovascular disease, hyperthyroidism, and glaucoma 3, 5

Phenylephrine is also an α-adrenergic agonist that works through vasoconstriction, commonly available in 10 mg oral doses, but less efficacious than pseudoephedrine as an oral decongestant due to extensive first-pass metabolism in the gut 1, 2, 3, 5

The American College of Allergy, Asthma, and Immunology states that oral decongestants are appropriate for short-term use in acute conditions but not recommended for long-term daily use 7
Pseudoephedrine is preferred over phenylephrine when maximum decongestant efficacy is needed, according to the American Academy of Otolaryngology 2, 5

The American Academy of Pediatrics recommends using oral decongestants with caution in children under 6 years of age due to risk of adverse effects including agitated psychosis, ataxia, hallucinations, and even death in rare cases 4
The American College of Obstetricians and Gynecologists advises caution during the first trimester of pregnancy due to reports of fetal heart rate changes 1
The National Institute on Drug Abuse notes that concomitant use with caffeine or other stimulants may increase the risk of adverse effects 3, 6