Zyrtec Special Precautions

Alcohol: At therapeutic doses, no clinically significant interactions have been demonstrated with alcohol (for a blood alcohol level of 0.5 g/L). Nevertheless, precaution is recommended if alcohol is taken concomitantly (see Interactions).
Increased risk of urinary retention: Caution should be taken in patients with predisposition factors of urinary retention (e.g. spinal cord lesion, prostatic hyperplasia) as cetirizine may increase the risk of urinary retention (see Adverse Reactions).
Patients at risk of convulsions: Caution in epileptic patients and patients at risk of convulsions is recommended.
Skin reactions: Pruritus and/or urticaria may occur when cetirizine is stopped, even if those symptoms were not present before treatment initiation (see Adverse Reactions). In some cases, the symptoms may be intense and may require treatment to be restarted. The symptoms should resolve when the treatment is restarted.
Allergy skin tests: Allergy skin tests are inhibited by antihistamines and a wash-out period of 3 days is recommended before performing them.
Food: The extent of absorption of cetirizine is not reduced with food, although the rate of absorption is decreased.
Activities requiring mental alertness: In clinical trials, the occurrence of somnolence has been reported in some patients taking Zyrtec. Due caution should therefore be exercised when driving a car or operating potentially dangerous machinery.
Ability to perform tasks that require judgement, motor or cognitive skills: Objective measurements of driving ability, sleep latency and assembly line performance have not demonstrated any clinically relevant effects at the recommended dose of 10 mg.
However, patients who experience somnolence should refrain from driving, engaging in potentially hazardous activities or operating machinery.
Patients intending to drive, engaging in potentially hazardous activities or operating machinery should not exceed the recommended dose and should take their response to the medicinal product into account.
Use in Children: The use of the film-coated tablet formulation is not recommended in children aged less than 6 years since this formulation does not allow for appropriate dose adaptation. It is recommended to use a paediatric formulation of cetirizine.