SUDAFED 12 HOUR
Clinical safety rating
cautionComprehensive clinical and safety monograph for SUDAFED 12 HOUR (SUDAFED 12 HOUR).
Pseudoephedrine is a sympathomimetic amine that acts as an agonist at alpha-1 and alpha-2 adrenergic receptors, causing vasoconstriction of nasal mucosa and reducing nasal congestion.
| Metabolism | Hepatic metabolism via N-demethylation to active metabolite; primarily excreted unchanged in urine |
| Excretion | Renal: 74-95% as unchanged drug; 1-4% as active metabolite (norpsuedoephedrine); biliary/fecal: minimal (<1%) |
| Half-life | 8-10 hours in adults with normal renal function; prolonged to 19-24 hours in renal impairment (CrCl <30 mL/min); shorter in children (3-4 hours) |
| Protein binding | 50-60% bound (primarily to albumin and alpha-1-acid glycoprotein) |
| Volume of Distribution | 2.6-3.5 L/kg in adults; indicates extensive tissue distribution (higher than total body water) |
| Bioavailability | Oral: 90-100% (immediate-release); sustained-release: approximately 95% |
| Onset of Action | Oral: 15-30 minutes; peak effect: 1-2 hours |
| Duration of Action | Sustained-release formulation: 12 hours; immediate-release: 4-6 hours; clinical decongestant effect lasts up to 12 hours with SUDAFED 12 HOUR |
| Molecular Weight | 165.23 |
120 mg orally every 12 hours, extended-release tablets. Maximum 240 mg per day.
| Dosage form | TABLET, EXTENDED RELEASE |
| Renal impairment | GFR 30-50 mL/min: reduce dose to 60 mg every 12 hours. GFR <30 mL/min: use is contraindicated. |
| Liver impairment | Child-Pugh A: no adjustment. Child-Pugh B or C: consider reducing dose or extending interval due to reduced clearance; specific guidelines not established. |
| Pediatric use | Children 6-12 years: 60 mg orally every 12 hours; maximum 120 mg/day. Children <6 years: not recommended. |
| Geriatric use | Start at lower end of dosing range (60 mg every 12 hours); monitor for CNS stimulation, hypertension, and urinary retention. |
| 1st trimester | Avoid unless benefit outweighs risk; potential for vasoconstriction reducing uterine blood flow. |
| 2nd trimester | Use only if necessary; monitor for maternal hypertension and fetal effects. |
| 3rd trimester | Avoid near term; may cause neonatal irritability, tachycardia, and hypertension. |
Clinical note
Comprehensive clinical and safety monograph for SUDAFED 12 HOUR (SUDAFED 12 HOUR).
| Placental transfer | Pseudoephedrine crosses the placenta; degree of transfer is moderate, with fetal levels similar to maternal levels. |
| Breastfeeding | Enters breast milk in small amounts; unlikely to cause adverse effects in term infants. However, use with caution due to potential for decreased milk production and irritability in infants. |
| Lactation Rating | L2 - Safer |
| Teratogenic Risk | Category C. First trimester: Possible risk of gastroschisis (limited data). Second and third trimesters: Uterine vasoconstriction, reduced placental perfusion; avoid due to risk of fetal hypoxia, tachycardia, and intrauterine growth restriction. No adequate well-controlled human studies. |
| Fetal Monitoring | Maternal: Blood pressure, heart rate, signs of hypertension or tachycardia. Fetal: Ultrasound for growth (if chronic use), fetal heart rate monitoring if used near term. Avoid use in preeclampsia or hypertension. |
| Fertility Effects | No specific human data. Animal studies show no effect on fertility at clinically relevant doses. Potential indirect effects due to vasoconstriction on uterine blood flow, but no evidence of impaired fertility. |
■ FDA Black Box Warning
None
| Serious Effects |
Severe hypertensionCoronary artery diseaseConcurrent MAOI therapyNarrow-angle glaucomaUrinary retention due to prostatic hypertrophy
| Precautions | Cardiovascular effects: hypertension, palpitations, tachycardia, CNS stimulation: insomnia, nervousness, dizziness, Exacerbation of narrow-angle glaucoma, Exacerbation of prostatic hypertrophy/urinary retention, Diabetes mellitus: may increase blood glucose |
| Food/Dietary | Avoid caffeine-containing foods and beverages (coffee, tea, cola, chocolate) as they may increase central nervous system stimulation and exacerbate side effects like nervousness and insomnia. High-tyramine foods (aged cheeses, cured meats, fermented products) should be limited in patients taking MAOIs, but no direct interaction with pseudoephedrine alone. Alcohol may increase dizziness and should be avoided. |
| Clinical Pearls | Pseudoephedrine is a sympathomimetic amine that causes vasoconstriction; avoid in patients with severe hypertension, coronary artery disease, or narrow-angle glaucoma. Extended-release formulation provides 12-hour symptom relief. Use with caution in patients with diabetes, hyperthyroidism, or prostatic hyperplasia. Monitor for nervousness, dizziness, or insomnia. Not recommended for use with MAOIs or within 14 days of stopping MAOIs. |
| Patient Advice | Do not crush or chew the tablet; swallow whole with water. · Take with food or milk if stomach upset occurs. · Avoid taking within 4-5 hours of bedtime to prevent insomnia. · Do not exceed one tablet every 12 hours; maximum 2 tablets in 24 hours. · Discontinue and consult doctor if symptoms persist beyond 7 days or are accompanied by fever. · Avoid using other medications containing pseudoephedrine or other decongestants. · Do not use if you have high blood pressure, heart disease, or are taking MAOIs. |
Loading safety data…