Doctors prescribe the brand name drug Zyrtec, generically called cetirizine, to treat the symptoms of hay fever and allergies. This drug works by blocking histamine, a substance released when someone comes into contact with an allergen. The histamine-blocking effects of Zyrtec work for allergies caused by dust mites, molds, pollen, animal dander and other allergens. Because this drug has several possible dangers, discuss any necessary precautions with a physician.
Impaired Driving
Zyrtec can cause sleepiness and other side effects that lead to impaired driving. Dr. John Bloomfield of the University of Minnesota compared driving performance among people who drank alcohol, took a traditional antihistamine and took a non-sedating antihistamine. The group members who drank alcohol drank enough to achieve a 0.10 blood alcohol concentration. Bloomfield found that both alcohol and the traditional antihistamine-impaired driving performance. Bloomfield delivered the results of his research during the 2001 Advanced Transportation Technologies Seminar Series at the University of Minnesota.
Allergic Reactions
Although doctors prescribe Zyrtec to treat allergies, it is possible to have an allergic reaction to cetirizine or other Zyrtec ingredients. When an allergic reaction occurs, it causes difficulty breathing, drooling, wheezing, tongue swelling, difficulty speaking, swelling around the mouth, difficulty speaking or dizziness.
Irregular Heartbeat
DailyMed, a website published by the National Institutes of Health, indicates that Zyrtec could cause fast heartbeat or heart palpitations. Normal heart range ranges from 60 to 100 beats per minute in adults, according to the Cleveland Clinic. If you experience a heart rate consistently above 100, consult a physician to determine if a more serious problem is causing the change.
Mental Changes
Zyrtec causes delayed reaction times and difficulty concentrating. Other mental changes caused by this drug include abnormal thinking, anxiety, depression, nervousness, sleep disorders and paranoia. If these mental changes occur, the prescribing physician may recommend a smaller dose of Zyrtec or a change to another drug with fewer side effects.
Seizures
Drugs.com reports that Zyrtec causes seizures in some patients. Seizures occur when the brain has a sudden surge of electrical activity. The signs and symptoms of a seizure include jerky movements, loss of consciousness and a feeling of pins and needles. Falling on the floor during a seizure increases the risk for injury. If someone has a seizure in your presence, clear the area of hard objects and loosen the victim’s clothing. The Epilepsy Foundation recommends turning the victim on his side to keep the airway free of obstructions.
Overdose
When taken improperly, Zyrtec causes overdose symptoms that include drowsiness, restlessness and irritability. If an overdose victim stops breathing or collapses, contact emergency services for assistance.
