Question: what are the side effects of long term use of zyrtec?
Answer: Nervous system. Very common (10% or more): Somnolence (up to 14.3%), headache (up to 14%) ... 
Gastrointestinal. ... 
Respiratory. ... 
Other. ... 
Psychiatric. ... 
Musculoskeletal. ... 
Dermatologic. ... 
Ocular.