pseudoephedrine (OTC)

Frequency Not Defined

Tremor

Restlessness

Insomnia

Nausea

Vomiting

Nervousness

Hypertension

Atrial fibrillation

Myocardial infarction

Ventricular premature beats

Ischemic colitis

Contraindications

Hypersensitivity

Severe hypertension, severe CAD

Within 14 days of MAO inhibitor therapy

Cautions

Use caution in mild to moderate hypertension, cardiac disease, hyperthyroidism, hyperglycemia, BPH, DM, renal impairment, seizure disorder, thyroid dysfunction, glaucoma, lactation

Elderly may be more sensitive to side effects

When used for self-medication, see health-care provider if symptoms do not improve within 7 days or are accompanied by fever

Some products may contain sodium

Some dosage forms may contain sodium benzoate/benzoic acid; large amounts have been associated with a potentially fatal toxicity (gasping syndrome) in neonates

Many combo formulations are switching to phenylephrine due to restrictions arising from easy conversion to methamphetamine (the Combat Methamphetamine Epidemic Act of 2005 bans OTC sales of cold medicines that contain ingredients, such as pseudoephedrine, commonly used to make methamphetamine)

Pregnancy

Avoid, during first trimester; may be associated with possible risk of gastroschisis, small intestinal atresia, and hemifacial microsomia due to pseudoephedrine’s vasoconstrictive effects; magnitude of risk unknown

Fetal tachycardia reported following maternal use of extended release formulation for multiple days

Lactation

Excreted in breast milk; irritability reported in nursing infants (limited data); milk production may be decreased in some women

Pregnancy Categories

A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.

B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.

C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done.

D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk.

X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist.

NA: Information not available.

Mechanism of Action

Alpha-adrenergic agonist of receptors present in respiratory mucosa, causing vasoconstriction; directly stimulates beta-adrenergic receptors and causes bronchial relaxation, as well as increased heart rate and contractility.

Duration

60 mg: 3-8 hr

120 mg: 12 hr

Absorption

Minimal systemic

Onset: 30 min (PO)

Peak plasma time: 1.97 hr

Concentration: 422 ng/mL

Metabolism

Liver, by N-demethylation

Metabolites: Inactive

Elimination

Half-life: 9-16 hr (adults; urine pH 8); 3-6 hr (adults; urine pH 5)

Clearance: 7.3-7.6 mL/min/kg

Excretion: Urine