Not nesecesarily. If you want, split the pills for a week. If there in capsules figure out a way to get half of the powder out and ingest it.
The thing you should be more worried about is getting off this horrendous drug. Easy to get on, very hard to get off. Possibly ask your doctor for an alternative to ssri drugs for you as they can be very physically addicting, though he may feel this is the drug you need. If you don't believe me type in
Lexapro or SSRI WITHDRAWL in googles search engine and do some research. Then ask yourself if this is the drug you need. There are several other anti-deps out there that are not ssri.