Yes, you can take Benadryl with Suboxone, but with caution.
Benadryl is an antihistamine medication often used for allergies which can also be sedating. It should be used cautiously in combination with Suboxone. Antihistamine medications like Benadryl turn off histamine receptors. One of their side effects is drowsiness.
If you are using Benadryl for allergies and are worried about becoming too sedated in combination with Suboxone, another option would be loratadine, sold under the brand name “Claritin”. Loratadine is also an antihistamine but is less sedating than Benadryl.
Talk to your doctor about combining multiple sedating medications at a time.