What to Know About Prophylactic Antibiotics

Medically Reviewed by Dan Brennan, MD on April 30, 2021

Prophylactic antibiotics are antibiotics that you take to prevent infection. Normally, you take antibiotics when you have an infection. Your doctor may give you antibiotics ahead of time to prevent infection in some situations where your risk of infection is high.

Why Are Prophylactic Antibiotics Prescribed?

Prophylactic antibiotics are given for many different reasons. Here are the most common.

Dental procedures. Bacteria from your mouth can enter your bloodstream during some dental procedures. This is not normally a problem for people with healthy immune systems. They can easily fight off many infections. People with certain conditions are more likely to develop infections. Some of these include:

Surgeries. Some types of surgery have a high risk of infection. Your doctor will probably give you prophylactic antibiotics if you're having one of these types of surgeries. Some of these surgeries include:

Labor and delivery. There are some circumstances when you might need prophylactic antibiotics during labor and delivery. Some of these circumstances may include:

Chronic infections. Your doctor may give you antibiotics to prevent infections if you have recurrent chronic infections. The most common of these are urinary tract infections (UTI), recurrent skin infections, and frequent flare-ups of chronic obstructive pulmonary disease (COPD).

Weakened immune system. You may need prophylactic antibiotics before a procedure if you have a weakened immune system. Some reasons you might have a weak immune system can include:

What Are the Benefits of Prophylactic Antibiotics?

Prophylactic antibiotics decrease your risk of developing infections that can sometimes be life-threatening. Prophylactic antibiotics can also stop a chronic or recurrent infection from coming back.

What Are the Risks of Prophylactic Antibiotics?

Antibiotic resistance. The biggest concern with prophylactic antibiotics is antibiotic resistance. This is a problem that affects everyone, not just people taking prophylactic antibiotics. Antibiotic resistance happens when germs such as bacteria and fungi learn to defeat the antibiotics that previously killed them. They become very difficult to treat when this happens.

Research has shown that antibiotic resistance often happens through the following process:

  • There are a lot of germs, but only a few are resistant to antibiotics.
  • Antibiotics kill not only the germs causing your disease but also the beneficial bacteria that protect your body.
  • The antibiotic-resistant bacteria spread and take over.
  • The antibiotic-resistant bacteria then pass along their resistance to other bacteria.

Many modern medical treatments depend on antibiotics to be effective. These treatments include:

Side effects. Like all medicines, antibiotics can have side effects. Some side effects from antibiotics can include:

Show Sources


ACOG: "Use of Prophylactic Antibiotics in Labor and Delivery."

ASHP Therapeutic Guidelines: "Clinical Practice Guidelines for Antimicrobial Prophylaxis in Surgery."

CDC: “Antibiotic / Antimicrobial Resistance (AR / AMR),” "Antibiotic Prescribing and Use."


Journal of Antimicrobial Chemotherapy: "Opportunities to reduce antibiotic prescribing for patients with COPD in primary care: a cohort study using electronic health records from the Clinical Practice Research Datalink (CPRD)."

Mayo Clinic Proceedings: "Antimicrobial Prophylaxis in Adults."

Milken Institute School of Public Health: "What Is Antibiotic Resistance?"

The Reference Manual of Pediatric Dentistry: "Antibiotic Prophylaxis for Dental Patients at Risk for Infection."

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