it's possible to have an adverse reaction to any medication. many people think over-the-counter medications are somehow "safer" than prescription drugs. this is not the case. all drugs can (and do) cause adverse reactions in some people. among the many possibilities any given person could have an adverse reaction to: dyes in the product; inert ingredients in the product (such as fillers and binders); or the active ingredient itself. you don't say what symptoms you're interpreting as an "adverse reaction " but in general if you take any kind of medication (prescription or over-the-counter) and experience a rash swelling of the lips/tongue/face or difficulty breathing you should seek medical treatment. a rash alone does not necessarily warrant a trip to the emergency room but the other symptoms do. also in general once you have experienced an adverse reaction to a drug you should never take it again. if you have questions about any medications you take even over-the-counter ones you can always consult your health care provider or a pharmacist. wishing you well!
why did i have an adverse reaction after taking gas x