What side effect is most commonly associated with penicillins?

Penicillins are a class of antibiotics commonly used to treat bacterial infections. Among their side effects, diarrhea is frequently observed, primarily because penicillins can disrupt the natural balance of bacteria in the gut. This disruption might lead to gastrointestinal disturbances, including diarrhea. This effect is particularly notable in patients as the antibiotic acts not only on pathogenic bacteria but can also affect the normal flora of the intestines.

It’s important to note that while diarrhea is a common side effect of penicillins, other side effects such as allergic reactions, which can manifest as rashes or anaphylaxis, are also significant considerations. However, the most prevalent gastrointestinal side effect remains diarrhea, making it a critical aspect to monitor in patients receiving penicillin therapy.