Will there be a problem taking Zyrtec and grapefruit?

There is no direct interaction between Zyrtec (cetirizine) and grapefruit, so taking them together generally should not pose a problem. However, grapefruit can affect the metabolism of many medications, so it's always wise to consult with a healthcare professional before combining them. If you have specific concerns or are taking other medications, it's best to seek personalized advice.