cetirizine/pseudoephedrine (OTC)

1-10%

Insomnia (4%)

Xerostomia (4%)

Fatigue/somnolence (2%)

Pharyngitis (2%)

Dizziness (1%)

Epistaxis (1%)

Sinusitis (1%)

Contraindications

Hypersensitivity

Narrow-angle glaucoma

Urinary retention

Severe hypertension

Severe coronary artery disease

Within 14 days of taking MAOIs

Cautions

Adrenergic agents may cause arrhythmias, dizziness, insomnia, tremor, or weakness

May cause sedation; caution with tasks requiring cognitive abilities (eg, driving, operating machinery)

Alcohol may exacerbate sedation and cognitive abilities

Caution with history of diabetes mellitus, hypertension, hyperthyroidism, increased IOP, ischemic heart disease, prostatic hypertrophy, or renal function impairment

Pregnancy Category: C

Lactation: Each ingredient is distributed in breast milk, caution advised

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

Cetirizine: Histamine H1-receptor antagonist

Pseudoephedrine: Alpha adrenergic agonist; decongestant in respiratory tract mucous membranes

Pharmacokinetics

Half-Life: 7.9 hr (cetirizine); 6 hr (pseudoephedrine)

Onset: 20-60 min (cetirizine); 30 min (pseudoephedrine)

Vd: 2.6-3.3 L/kg (cetirizine)

Peak Plasma Time:2.2 hr (cetirizine); 4.4 hr (pseudoephedrine)

Peak Plasma Concentration: 422 ng/mL (pseudoephedrine)

Protein Bound: 93% (cetirizine)

Metabolism: Liver, low first-pass (cetirizine)

Clearance: 7.3-7.6 mL/min/kg (pseudoephedrine)

Excretion: Cetirizine: feces (10%), urine (70%); pseudoephedrine: urine