There are many mild to severe side effects of Zyrtec that can include drowsiness, dry nose, dry mouth, difficulty sleeping, throat pain, irregular heart beat, bronchospasm, a heart pounding sensation, liver problems, seizures, diarrhea, blurred vision, severe water retention and painful urination, notes WebMD. Some patients may also develop hepatitis or incur an allergic reaction that is life threatening.
There are additional less severe side effects from Zyrtec, such as increased or decreased appetite, low energy level, increased nervous feelings, nightmares, a sensation of ringing ears, stomach cramps and sun-sensitive skin. Some people will also gain weight on Zyrtec, reports WebMD.
Most people only experience a few side effects, but if a patient experiences too many of these symptoms, then the person should stop the medication. For more severe symptoms, patients should seek medical attention, warns Drugs.com.
Zyrtec is intended for use as an allergy medication for both adults and children, and it's taken orally through a liquid or pill. The medication should only be given to children after consulting with a doctor. It is an antihistamine, which means that it is often recommended as an alternative medication to avoid drowsiness.