Benadryl isn’t safe
Benadryl causes significant sedation. One study in a driving simulator showed an ordinary adult dose of Benadryl caused worse driving than a blood alcohol level of 0.1 percent (that’s between buzzed-drunk and frat-party drunk). Ordinary doses of Benadryl can also cause urinary retention, dizziness, trouble with coordination, dry mouth, blurry vision, and constipation. Especially in older individuals, diphenhydramine can cause delirium and contribute to long term dementia.
You be the judge.