Zyrtec (Cetrizine) is an antihistamine used to treat seasonal allergies. The National Institutes of Health (NIH) reports that in clinical trials, Zyrtec is shown to be effective in treating histamine induced rash or urticaria (generalized itchy rash) of unknown cause. NIH also reports that most side effects caused by Zyrtec are rare (less than 2 percent of clinical trial populations); however, it may trigger a negative reaction, so refer to the NIH reference for a complete list of all potential adverse reactions.
Central Nervous System Side Effects
Zyrtec may cause some drowsiness and sedation. The NIH reports that the degree of sedation is related to the dose of Zyrtec; headache and depressed mood are also possible. Other rare central nervous system side effects include lack of coordination, tremor, weakness or paralysis, leg cramps, twitching, visual field disturbances and vertigo.
Gastrointestinal Side Effects
The NIH reports the following rare gastrointestinal (GI) side effects caused by Zyrtec: increased appetite, increased problems with cavities, indigestion and burping, flatulence and constipation. Other rare yet more serious GI adverse reactions to Zyrtec are gastritis, blood in the stool, ulcerative stomatitis and rectal hemorrhage.
Dermatologic Side Effects
Zyrtec may cause multiple rare dermatologic side effects, including dry skin, itching, dermatitis, rash, photosensitivity, acne and hair loss. Angioedema (a rash condition), itching, and swelling of both external and internal areas of the body are all possible.
Side Effects to Special Senses
Although rare, Zyrtec may cause ototoxicity. Tinnitis (ringing in the ear), deafness, and earache may occur and should be reported to a health care provider. Altered taste and taste loss may be experienced by some people taking Zyrtec.
Visual disturbances reported by the NIH include dry eyes, conjunctivitis, eye pain, glaucoma, loss of accommodation, ocular hemorrhage and blindness.
Respiratory System Side Effects
The NIH reports multiple potential side effects caused by Zyrtec ranging from increased sputum production, increased occurrence of upper respiratory infections, rhinitis and bronchitis. Difficulty breathing may be experienced as well as hyperventilation.
Generalized Side Effects
Zyrtec has many, although rare, generalized side effects. The NIH reports that patients taking Zyrtec may experience any of the following symptoms: back pain; chest pain; generalized edema to include edema of the face, especially around the eyes, and of the legs and abdomen. Fever with rigors may occur, as well as hot flashes, increased weight, malaise, nasal polyp, pain and pallor.
As with all medications, allergic reactions to the active and inactive ingredients in Zyrtec is possible. Angioedema or closing of the throat may occur. Seek a doctor help if any of these symptoms occur.
References
- National Institute of Health
- Wilson, B. A., Shannon, T. M., & Shields, K. M. (2010). Pearson Nurse's Drug Guide 2010. New York: Pearson.
