If you are being treated with any of the following medications, you should not use vitamin B5 supplements without first talking to your health care provider.
Antibiotics, Tetracycline -- Vitamin B5 interferes with the absorption and effectiveness of the antibiotic tetracycline. You should take B vitamins at different times from tetracycline. (All vitamin B complex supplements act in this way and should therefore be taken at different times from tetracycline.)
Drugs to treat Alzheimer's disease -- Vitamin B5 may increase the effects of a group of drugs called cholinesterase inhibitors, which are used to treat Alzheimer's, potentially leading to severe side effects. These drugs should not be taken with B5 unless under a doctor's supervision. Cholinesterase inhibitors include:
Pantothenic Acid; Vitamin B5 (Pantothenic Acid)