What are common side effects associated with antibiotics?

Antibiotics are widely used to treat bacterial infections, and various side effects can occur due to their effects on both harmful and beneficial microorganisms in the body. The choice highlighting nausea, diarrhea, and allergic reactions accurately reflects common side effects associated with antibiotic use.

Nausea and diarrhea are particularly prevalent because antibiotics can disrupt the normal gut microbiota, leading to gastrointestinal disturbances. This is why patients often experience these symptoms when taking antibiotics. In addition, some patients may experience allergic reactions, which can range from mild skin rashes to severe anaphylaxis. This broad spectrum of potential side effects aligns with the known pharmacological effects of antibiotics and the body's response to them.

The other options list side effects that are less commonly associated with antibiotics. Headaches and dizziness, while they can occur, are not among the most typical reactions. Insomnia and weight gain are not typical side effects associated with antibiotic use, and while fatigue and muscle cramps may occur in some instances, they are not recognized as standard reactions to antibiotics. Therefore, the second choice accurately represents the expected side effects of antibiotic therapy.