Side Effects of Antibiotics: What You Should Know

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As with any medication, antibiotics can have side effects. Patients should consult with their prescribing physician and pharmacist regarding any side effects of antibiotics they may experience based upon the antibiotic(s) prescribed, other medications being taken and any other health conditions the patient may have.

Antibiotic Side Effects

Some of the most common side effects include upset stomach, nausea, vaginal yeast infections (women), sensitivity to sunlight, diarrhea, headache and rash. Some patients may experience an allergic reaction to certain antibiotics.

Antibiotics with Alcohol

The Mayo Clinic reports that while alcohol won’t typically dilute the effect of most antibiotics, when mixed, there can be side effects. Some of the most common side effects caused by mixing alcohol with antibiotics are enhanced stomach upset, dizziness and drowsiness. Some reactions can be more extreme, and can include a rapid heartbeat or vomiting.

Antibiotics with Birth Control Pills

Another antibiotic side effect is how it may affect other prescription medication, such as birth control pills. Research regarding the effectiveness of birth control pills while taking antibiotics has shown inconclusive results, except for the specific antibiotic rifampin. This antibiotic can cause birth control pills to become less effective.

In other cases, while the possibility is there that in some cases other antibiotics could cause a lessening of effectiveness, research has not shown this conclusively. Other forms of birth control, such as condoms, should be used by anyone concerned about lowered birth control effectiveness while taking an antibiotic.

Antibiotics Abuse

Another side effect of antibiotics is the overuse or misuse of them. This is also called antibiotic abuse. The abuse of antibiotics is not a matter of an addiction or an attempt to get high, but rather, the act of taking antibiotics for viral infections. Antibiotics can be helpful in treating bacterial infections, but not viral infections. When taken repeatedly, especially for viral infections, the patient can develop an ‘antibiotic resistance’, which makes it harder to combat the bacterial infection the antibiotic is supposed to treat.

Illnesses such as colds, bronchitis, and most sore throats are all caused by viruses. These are best not treated with antibiotics, but with fluids, over the counter products and rest.

According to the CDC, antibiotic resistance, caused by inappropriate widespread use of antibiotics, has created “an economic burden on the entire healthcare system. Resistant infections cost more to treat and can prolong healthcare use.” The estimates are that in the United States, $20 billion is wasted in healthcare costs alone due to antibiotic resistance, with societal costs and additional hospital stays adding more than $35 billion to the total.


Multiple things need to be considered when it comes to side effects of antibiotics. These include interactions with other medications, affects when taken with alcohol and the overuse or misuse that can create antibiotic resistance. It is best for the patient to be sure a bacterial infection is present before taking any antibiotic.


Merck. Manuals: Antibiotics.

Steckelberg, James, M., M.D. “What are the effects of drinking alcohol while taking antibiotics?”

Mayo Clinic Staff. “Antibiotics: Misuse puts you and others at risk”

CDC. “Get Smart: Know When Antibiotics Work”