Zyrtec (cetirizine HCl 5-mg and 10-mg) In Zyrtec studies, side effects were mild or moderate, including drowsiness, fatigue and dry mouth in adults, and drowsiness, headache, sore throat and stomach pain in children. Drowsiness occurred in between 11% and 14% in adults, depending on dose, compared to 6% taking placebo. In children, drowsiness occurred in between 2% and 4%, depending on dose, compared to 1% taking placebo. Zyrtec-D 12 Hour™ (cetirizine HCl 5mg/pseudoephedrine HCl 120mg) Extended Relief Tablets In Zyrtec studies, side effects were mild or moderate, including drowsiness, fatigue and dry mouth in adults, and drowsiness, headache, sore throat and stomach pain in children. Drowsiness occurred in between 11% and 14% in adults, depending on dose, compared to 6% taking placebo. In children, drowsiness occurred in between 2% and 4%, depending on dose, compared to 1% taking placebo. Pseudoephedrine hydrochloride may cause mild CNS stimulation in hypersensitive patients. Nervousness, excitability, restlessness, dizziness, weakness or insomnia may occur. Zyrtec is available in 5-mg and 10-mg tablets and 1-mg/mL syrup. Zyrtec-D 12 Hour is available in an extended release tablet. |