medication safety

My 5 year old daughter has a skin infection and they put her on cephalexin yesterday. her medication was accidentally left out on the kitchen counter overnight. should i give it to her this morning, or has the medication been compromised by our not refrigerating it overnight?

[Sandra Y, RPh]

I would recommend that you contact your pharmacy and get another bottle. When this medication is left out of the refrigerator for a long period of time, it begins to clump and stick together (aggregate). Once aggregation occurs, it is hard to break it up, therefore the amount of drug you are giving your child may not be the proper dose. Also, when refrigerated, the medication expires after 14 days. If left out of the refrigerator, the expiration date decreases.