Cetirizine: Mechanism of Action and Contraindications
Aug 06, 2021
Source: Cainiu Health
Dr. Sun Yinghua
Introduction
Drowsiness and palpitations. Cetirizine may cause drowsiness, making patients feel sleepy. It is not recommended for patients who need to drive or attend classes the following day, as it may impair driving ability and reduce concentration. Cetirizine may also produce cardiac side effects; therefore, patients with preexisting heart conditions should avoid its use, as it may trigger symptoms such as palpitations and other cardiac discomfort.
Cetirizine is a second-generation antihistamine. Many people used chlorpheniramine (commonly known as “Pulmin”) during childhood; this is a first-generation antihistamine, which may cause drowsiness—i.e., patients often feel sleepy after taking it. Chlorpheniramine must be taken three times daily, and patients may experience persistent dizziness and mental fogginess throughout the day.
A key advantage of second-generation antihistamines is that only one dose per day is required. Patients can take the medication just before bedtime, so the peak drug effect—and consequently the strongest sedative effect—occurs during sleep. By morning, upon waking, drowsiness is significantly reduced or even absent.
Patients scheduled to drive or attend classes the following day should avoid cetirizine, as it still carries a notable risk of drowsiness, potentially impairing concentration while driving or during academic activities.Another significant drawback of cetirizine is its potential cardiac side effects. It should generally be avoided in elderly patients with compromised cardiac function, as it may provoke palpitations or other cardiac discomfort.
