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When did you give him?
At this age with this body weight, we usually advise to give 3/4 tsp of benadryl about 3.75 ml.
When some has spilt out, you probably gave 3/4 tsp.
Weight needs to be considered too.
Though benadryl is available otc, but we usually advise to give it after examination by doctor.
That is normal dose but 3/4 tsp is the maximum safe dose.
A little overdose can make him sleepy.
Do not worry.
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