Do antibiotics have side effects?

John Manna, FNP

Lifestyle Medicine

Treating ear infections, strep throat and other common illnesses often involves being prescribed an antibiotic, combating the bacteria that caused the infection in the first place and helping you recover more quickly. Have you ever wondered exactly how they work? Do antibiotics have side effects?

John Manna, FNP, explained the potential side effects of antibiotics and whether it’s possible to have a severe reaction to common antibiotics.

How do antibiotics work?

“Basically, antibiotics work specifically on treating a bacterial infection,” said Manna. “They don’t have any benefit for a viral infection because they can’t target that illness. But if your sickness is bacterial, the antibiotic can kill the bacteria, or slow or suspend its growth, depending on which one you take and the cause of your illness.”

Antibiotics don’t do all the work themselves, of course. Once the bacterial growth has slowed or stopped, your immune system is able to step in and more effectively fight off the infection.

Do antibiotics have side effects?

“The answer to what side effects you might expect when taking an antibiotic is going to depend a lot on both which one you have been prescribed and also you as an individual,” said Manna. “Different people react differently to different medicines, and your current level of health and potential sensitivities can all affect your experience.”

Common side effects of antibiotics include:

• Raised, itchy skin rash (this is especially common if the antibiotic ampicillin is taken when you have mono)
• Dizziness
• Diarrhea
• Nausea
• Yeast infection
• Sensitivity to sunlight (if taking tetracyclines)
• Coughing

Most of these side effects are mild and cause little more than some irritation. If you experience more severe side effects (shortness of breath, tightness or pain in the chest, swelling) head to the nearest ER for immediate assistance.

Will changing what I eat or do lessen the chance of side effects?

“The term ‘antibiotic’ includes a huge variety of different medicines that have different potential side effects,” said Manna. “Ask your medical provider when they are prescribed if there is anything specific you need to avoid eating, drinking or doing while taking them.”

How can I lessen side effects while taking antibiotics?

Depending on which side effects you are dealing with, there may be options to help minimize your discomfort. With any side effect you experience, reach out to the provider who prescribed the medication and ask for advice on what to do. They may be able to offer some solutions, including potentially changing which medication you are taking.

Are there any long-term side effects to taking antibiotics?

“One downside to antibiotics is that they can’t differentiate very well between the good bacteria that helps our bodies function and the bad bacteria making us sick,” said Manna. “When you take antibiotics for a prolonged period of time, they may kill off beneficial bacteria in the gut, which can cause longer-term complications.”

Infections like Clostridium difficile, commonly called C. diff, can occur when the balance of good bacteria in the gut is disrupted thanks to taking antibiotics. In some cases, it can take months or even years for the gut to fully recover. These infections are more common when you take antibiotics for a long time, or if you have to take an exceptionally strong antibiotic.

“Another problem, which has become far more serious, is one you’ve probably seen in the news,” said Manna. “The possibility for your infection to become resistant to antibiotics, making them less effective and less able to fight off your infection.”

Antibiotic resistance has become more common over time, thanks to overprescription of antibiotics for viral infections simply due to the belief that they will help the patient to feel better, and also due to individuals who are prescribed antibiotics who don’t take the full course.

When you stop taking antibiotics early, you may not have fully fought off the infection yet. The bacteria left will be those that were able to resist the antibiotics, so when your infection comes roaring back, the same antibiotic might not be able to treat it effectively any longer. Make sure you ask your provider any questions you have during your appointment, and take the antibiotic for the full course prescribed.