Hello young man.
RHINIL contains the drug cetirizine
, which is usually safe with long term use also.
The most common side effect is sedation. Caution should be practiced while driving vehicles or performing risky tasks such as handling machinery, etc to avoid accidents.
Also you should avoid alcohol or other sedative drugs as they may have additive effect.
You may have an occasional headache due to cetirizine. Else there are no major side effects.
Hope this was helpful to you.
Wish you the best health.