Which adverse effect is commonly associated with the use of penicillins?

The adverse effect commonly associated with the use of penicillins is GI disturbances. This is due to the way penicillins can disrupt the normal gut flora, leading to symptoms such as diarrhea, nausea, and vomiting. The gastrointestinal tract is sensitive to changes in its microbial environment, and the introduction of antibiotics like penicillins can alter the balance of beneficial bacteria, resulting in these digestive issues.

Other options such as heart palpitations, severe headaches, and visual disturbances are less typical for penicillin treatment. While some individuals may experience various side effects, the likelihood of GI disturbances occurring is well-documented and represents a more common response to penicillin therapy. This makes understanding the gastrointestinal side effects particularly important for patient management and counseling.