Tart cherry juice is good to drink but if you take certain medications such as blood thinners it can react with those medications so you should speak with your doctor if you take blood thinners or other medications to be sure that the tart cherry juice won't interfere with the medications you take.
Tart Cherry Juice contains a plant compound called quercetin that is what interacts and interferes with some medications.
If you are taking medications such as blood thinners drinking a cup of small glass of cherry juice at night or in the daytime should do no harm.
My mother takes medications and she drinks a cup of cherry juice at night to help her sleep and it's been a problem.