CLINICAL QUESTION
Does long-term use of adrenergic agonist oral decongestants increase blood pressure or cause other adverse effects in people older than 6 years?
EVIDENCE-BASED ANSWER
Adrenergic agonist oral decongestants taken for at least 7 days have little to no effect on blood pressure compared with placebo. These medications also appear to have little to no effect on heart rate or withdrawals due to adverse effects.1 (Strength of Recommendation: C, consensus, disease-oriented evidence, usual practice, expert opinion, or case series.)
PRACTICE POINTERS
Patients commonly use oral decongestants to treat nasal, pharyngeal, and sinus mucosal congestion due to allergies and upper respiratory tract infections.1 These medications constrict blood vessels by activating alpha-adrenergic receptors. Because of this vasoconstriction, it is thought that these medications may increase peripheral vascular resistance and heart rate, leading to increased blood pressure and increased risk for cardiovascular disease.1 This risk is thought to be even higher for people with hypertension, which affects nearly one-half of all US adults.2 The authors of this Cochrane review aimed to assess the effects of long-term daily use of oral decongestants on blood pressure and heart rate outcomes.1
This review included five randomized controlled trials with 882 participants older than 6 years.1 All of the studies were published between 1986 and 2019. The studies were not primarily designed to assess long-term effects on blood pressure, rather the adrenergic agonist oral decongestants were evaluated for effects on weight loss, nasal congestion, and female stress urinary incontinence compared with placebo. Cardiovascular comorbidities of the participants were not reported. All of the studies were in the outpatient setting in the United States, Finland, or Denmark. Pharmaceutical companies funded three of the studies.
Adrenergic agonist oral decongestants included ephedrine (one study), pseudoephedrine (one study), and phenylpropanolamine (three studies) administered daily for at least 1 week with varying doses, frequency, and formulation.1 Studies that evaluated phenylpropanolamine were published before 2000, when the drug was withdrawn from the US market due to an association with increased risk of blood pressure–related hemorrhagic strokes, especially in females.3 The main outcomes assessed in this Cochrane review were systolic and diastolic blood pressure (change from baseline), heart rate (change from baseline), and withdrawals due to adverse effects. The duration of follow-up was 1 to 7 weeks.1
Compared with placebo, oral decongestants may have little to no effect on systolic or diastolic blood pressure based on very low-certainty and low-certainty evidence, respectively.1 Compared with placebo, oral decongestants may have little to no effect on heart rate or withdrawals due to adverse effects (very low-certainty evidence and low-certainty evidence, respectively).
Variations in timing and accuracy of blood pressure measurements in the studies, lack of details on specific blood pressure monitors used, imprecision in effect estimates, and high risk of bias led investigators to conclude these results are based on overall low-quality evidence.1 With these limitations, the long-term effects of oral decongestants on blood pressure remain unclear. Current guidelines recommend avoiding sympathomimetic medications such as oral decongestants in patients with uncontrolled or resistant hypertension, with less clarity regarding patients with mildly elevated blood pressure.4
Future updates of this Cochrane review should exclude studies with phenylpropanolamine, which was effectively removed from all over-the-counter products in the United States and Canada, and focus only on currently available oral decongestants. Until well-designed studies are available, family physicians should continue to caution high-risk patients about using oral decongestants.
The practice recommendations in this activity are available at https://www.cochrane.org/CD007895.
