Help with a round pill

[hh21]

My sister has a pill problem, and we have found some new pills in her room and want to know what this could be that she is taking. I have been searching everywhere and cannot find any info on this.

She has the pills in a bottle with someone elses name, from another state, from a Vets office, for Baytril (which is an antibiotic and do not look like the pills she has), so we know they are not Baytril.

These pills are round, but have the marks in them so they can be cut into quarters, A light brown/tannish color and have the markings B 23 on them.

Any info would be greatly appreciated, we are very worried.Thank you

[tunafizzle]

What does the B look like, is it uppercase or lower case. If it is lowercase does it look like

[hh21]

its a capital B.