Sudafed (Pseudoephedrine) Prescribing Guidelines
Recommended Dosage
For adults and children 12 years and older, prescribe pseudoephedrine 60 mg every 4-6 hours, not exceeding 240 mg in 24 hours (8 tablets). 1
Age-Specific Dosing:
- Adults and children ≥12 years: 60 mg (2 tablets of 30 mg) every 4-6 hours; maximum 240 mg/24 hours 1
- Children 6-11 years: 30 mg (1 tablet) every 4-6 hours; maximum 120 mg/24 hours 1
- Children <6 years: Do not use 1
Clinical Efficacy
Pseudoephedrine demonstrates proven decongestant efficacy through objective measures. A randomized controlled trial of 238 patients with upper respiratory tract infections showed statistically significant reduction in nasal airway resistance compared to placebo after both single doses (p=0.006) and multiple doses (p<0.001). 2 The medication works by supplementing natural sympathetic nervous activity to nasal blood vessels, limiting the congestion phase of the nasal cycle while not affecting the decongestion phase. 3
The decongestant effect begins within 60 minutes and persists for 150 minutes after a single 60 mg dose, with significant improvements in nasal cavity dimensions measured by acoustic rhinometry (p=0.018 for cross-sectional area, p=0.003 for nasal volume). 4
Critical Precautions and Contraindications
Cardiovascular Considerations:
Pseudoephedrine can be used cautiously in medically controlled hypertensive patients, but monitor blood pressure and heart rate closely. A prospective study of 28 hypertensive patients taking 120 mg sustained-release pseudoephedrine twice daily showed no statistically significant changes in blood pressure or heart rate, though an upward trend was observed that may become clinically significant in larger populations. 5
- Monitor for heart rate increases of 2-4 beats per minute above baseline 2
- Avoid in patients with uncontrolled hypertension
- Use caution in patients with coronary artery disease, arrhythmias, or severe cardiovascular disease
Common Pitfalls to Avoid:
- Do not exceed maximum daily doses: Overdosing increases cardiovascular risks without additional therapeutic benefit
- Do not prescribe for children under 6 years: Safety and efficacy not established 1
- Warn patients about potential sleep disturbances: Mild insomnia reported in clinical trials 5
- Counsel male patients about possible urinary retention: Particularly those with prostatic hypertrophy 5
Duration of Treatment
Prescribe for short-term use only (3-7 days maximum). Studies demonstrate maintained efficacy over 3 days of treatment with objective measures, though subjective symptom scores may show tolerance. 2 Prolonged use beyond 7 days can lead to rebound congestion.
Drug Interactions and Special Populations
- Avoid concurrent use with MAO inhibitors or within 14 days of discontinuation
- Use caution with other sympathomimetics to avoid additive cardiovascular effects
- Pregnancy Category C: Use only if benefits outweigh risks
- Elderly patients: Start at lower end of dosing range due to increased sensitivity to sympathomimetic effects