Decongestant Use in Diving

Introduction to Decongestant Use

The British Thoracic Society guidelines recognize that Eustachian tube dysfunction is a legitimate indication for topical decongestants, and this principle extends to oral decongestants for diving prophylaxis 3
Pseudoephedrine works as an α-adrenergic agonist causing vasoconstriction, which reduces Eustachian tube mucosal edema and facilitates middle ear equalization during descent and ascent 1, 2

For divers with known congestion or history of equalization difficulty, the American College of Allergy, Asthma, and Immunology recommends considering pseudoephedrine 60 mg orally 30 minutes before diving 3, 4
Screen for contraindications before recommending pseudoephedrine: cardiovascular disease, uncontrolled hypertension, arrhythmias, coronary artery disease, cerebrovascular disease, hyperthyroidism, closed-angle glaucoma, or bladder neck obstruction 4, 3, 1

Pseudoephedrine causes modest systemic effects: increases systolic blood pressure by 0.99 mmHg and heart rate by 2.83 beats/min in normotensive individuals 1
Patients with controlled hypertension can generally use pseudoephedrine safely but require monitoring 4, 3
The combination of diving-related physiological stress with sympathomimetic effects warrants extra caution in those with cardiovascular disease 5

Middle ear barotrauma is a significant risk during diving, and failure to equalize can progress from discomfort to tympanic membrane hemorrhage or rupture 5
During ascent, expanding gas in the middle ear must vent through the Eustachian tube; obstruction can cause reverse squeeze with similar complications 5
Decongestants do not increase pulmonary barotrauma risk, but divers must understand that any medication causing drowsiness, altered consciousness, or impaired judgment is dangerous 5

Active upper respiratory infection with significant congestion should prompt dive cancellation rather than relying on decongestants to enable diving 3
Topical decongestants must be limited to ≤3 days of use to avoid rebound congestion (rhinitis medicamentosa) 3, 1, 2
Oral decongestants should be used with extreme caution in children under 6 years due to risks of agitated psychosis, ataxia, and hallucinations 4, 2

For recreational divers with occasional congestion, pseudoephedrine 60 mg taken 30 minutes pre-dive is the evidence-based standard 6
For divers with chronic rhinitis, intranasal corticosteroids started several days before diving provide better long-term management than repeated decongestant use 6
Phenylephrine is NOT recommended as it has poor oral bioavailability and unproven efficacy 4, 2