PSEUDOEPHEDRINE HYDROCHLORIDE
Clinical safety rating: safe
MAOIs can cause hypertensive crisis Can cause insomnia and tachycardia.
Pseudoephedrine is a sympathomimetic amine that acts as a decongestant by stimulating alpha-adrenergic receptors in the respiratory tract mucosa, causing vasoconstriction and reducing nasal congestion. It also has weak beta-adrenergic activity.
| Metabolism | Hepatic metabolism via N-demethylation (CYP450, primarily CYP2D6) to active metabolite pseudoephedrine; minor metabolism to other metabolites. |
| Excretion | Renal: 70-90% unchanged via glomerular filtration and tubular secretion; fecal: <1%; biliary: minimal |
| Half-life | Terminal elimination half-life: 5-8 hours in adults with normal renal function, prolonged in renal impairment (up to 16-20 hours in severe impairment) |
| Protein binding | Plasma protein binding: 20-30% (primarily to albumin and alpha-1-acid glycoprotein) |
| Volume of Distribution | Apparent Vd: 2.5-3.5 L/kg, indicating extensive tissue distribution beyond plasma volume |
| Bioavailability | Oral: 100% (complete absorption, minimal first-pass metabolism) |
| Onset of Action | Oral: 15-30 minutes; intranasal: 5-10 minutes |
| Duration of Action | Oral: 4-6 hours (immediate-release), up to 12 hours (extended-release); intranasal: 2-4 hours |
| Molecular Weight | 201.69 |
60 mg orally every 4 to 6 hours as needed; maximum 240 mg per day.
| Dosage form | TABLET, EXTENDED RELEASE |
| Renal impairment | GFR 10-50 mL/min: administer every 12 hours; GFR <10 mL/min: avoid use due to risk of accumulation. |
| Liver impairment | No specific adjustment recommended for Child-Pugh Class A or B; use with caution in severe hepatic impairment (Child-Pugh Class C) due to limited data. |
| Pediatric use | Children 6-11 years: 30 mg orally every 4-6 hours; maximum 120 mg/day. Children ≥12 years: same as adult dosing. |
| Geriatric use | Start at lower end of dosing range (30 mg every 6 hours) due to increased sensitivity and potential for adverse effects; monitor blood pressure and heart rate. |
| 1st trimester | Use only if potential benefit justifies potential risk to fetus; may be associated with gastroschisis in first trimester. |
| 2nd trimester | Use with caution; may cause uteroplacental insufficiency due to vasoconstriction. |
| 3rd trimester | Avoid near term; may cause uterine vasoconstriction and fetal hypoxia. |
Clinical note
MAOIs can cause hypertensive crisis Can cause insomnia and tachycardia.
| FDA category | Animal |
| Placental transfer | Crosses the placenta; peak fetal concentrations approximately 20% of maternal serum levels. |
| Breastfeeding | Excreted into breast milk in small amounts; use with caution in breastfeeding mothers, especially in infants with hypertension or cardiovascular conditions. |
■ FDA Black Box Warning
None.
| Common Effects | Insomnia |
| Serious Effects |
Severe hypertensionCoronary artery diseaseConcurrent MAOI therapyNarrow-angle glaucomaUrinary retention
| Precautions | Use with caution in patients with hypertension, cardiovascular disease, hyperthyroidism, diabetes, prostatic hypertrophy, or glaucoma. May cause CNS stimulation, nervousness, dizziness, or insomnia. Avoid in patients with severe coronary artery disease or angina. |
| Food/Dietary | Avoid foods high in tyramine (aged cheeses, cured meats, fermented products) as pseudoephedrine can potentiate hypertensive effects in combination with MAOIs. Caffeine-containing beverages may increase CNS stimulation and should be limited. Alcohol may exacerbate dizziness or sedation. |
Loading safety data…
| Lactation Rating | L2 (Safer) |
| Teratogenic Risk | First trimester: Increased risk of gastroschisis (OR 1.8) with first-trimester use; avoid use. Second and third trimesters: Uterine vasoconstriction may reduce placental perfusion; use only if benefit outweighs risk. No known structural teratogenicity beyond first trimester. |
| Fetal Monitoring | Monitor maternal blood pressure and heart rate due to potential hypertension and tachycardia. Assess fetal heart rate if used near term due to possible uterine vasoconstriction. Observe for signs of maternal CNS stimulation. |
| Fertility Effects | No known direct impact on fertility. May theoretically affect implantation via vasoconstrictive properties, but human data lacking. |
| Clinical Pearls | Pseudoephedrine is a sympathomimetic amine with both direct and indirect alpha-1 agonist activity, causing vasoconstriction of nasal mucosa. It is commonly used as a decongestant. Caution in hypertension, ischemic heart disease, hyperthyroidism, and BPH. Avoid in patients on MAOIs or within 14 days of discontinuation. Efficacy diminishes after 3-5 days due to tachyphylaxis; limit use to 5 days. Monitor for CNS stimulation, insomnia, palpitations. Use extended-release formulations for 12-hour coverage. |
| Patient Advice | Do not take this medication if you have high blood pressure, heart disease, or severe anxiety. · Avoid taking within 4-6 hours of bedtime to prevent insomnia. · Do not exceed the recommended dose; taking more can cause serious side effects like rapid heart rate. · If symptoms persist for more than 5 days, consult a healthcare provider. · This drug can be habit-forming; use only as directed. · Do not crush or chew extended-release tablets; swallow whole. |