Is there any over-the-counter antibiotic for acne?

Not in the USA: And that's a good thing. If an antibiotic is used alone, the bacteria that are involved with causing the illness tend to become resistant. You might or might not be able to get a retinoic acid derivative without a prescription. A physician's office visit is in order anyway if your acne hasn't responded to the benzoyl peroxide regimen you've been using; there may be other choices as well.