Antibiotic Prophylaxis: Precautions, Side Effects and Interactions

Prophylaxis is a measure designed to maintain health and prevent the spread of the disease.

Antibiotic Prophylaxis is the focus of this article and refers to the use of antibiotics to prevent infections.

Antibiotics are well known for their ability to treat infections. However, some antibiotics are also prescribed to prevent infections.

This is usually done only in certain situations or for people with particular medical problems. For example, people with abnormal heart valves have a high risk of developing infections, even after minor surgery.

This happens because bacteria from other body parts enter the bloodstream during surgery and travel to the heart valves.

To prevent these infections, people often take antibiotics before undergoing surgery, including dental surgery.

Antibiotics may also be prescribed to prevent infections in people with weak immune systems, such as those with AIDS or who have chemotherapy treatments for cancer.


But, still, healthy people with robust immune systems can sometimes receive antibiotics if they are going to undergo certain types of surgery that carry a high risk of infection or if they travel to parts of the world where they are prone to have an infection. That causes diarrhea, for example.

In all these situations, a doctor should be the one to decide if antibiotics are necessary. Unless a doctor says you should take antibiotics, it is not a good idea to self-medicate to prevent common infections.

Because the excessive use of antibiotics can lead to their immunity, the drugs are taken to prevent the infection should be used only for a short period.

Among the medicines used for antibiotic Prophylaxis are amoxicillin (a type of penicillin) and fluoroquinolones, such as ciprofloxacin (Cipro) and trovafloxacin (Trovan). These medications are available only by prescription and come in tablets, capsules, liquid, or injectable.

For surgical Prophylaxis, cephalosporin antibiotics are generally preferred. This class includes cefazolin (cefazolin, Kefzol), cefamandole (Mandol), cefotaxime (Claforan), and others.

The choice of the drug depends on its spectrum and the type of bacteria that are most likely to be found during surgery. For example, surgery on the intestines, which have many anaerobic bacteria, may require cefoxitin (Mefoxin), while in heart surgery, there are no anaerobes, cefazolin may be preferred.

The recommended dose in Antibiotic Prophylaxis

The recommended dose depends on the antibiotic prescribed and its use. The patient is advised to consult with the doctor or dentist who prescribed the medication or the pharmacist who filled the prescription for the correct amount.

It is recommended that the patient be sure to take the medication exactly as prescribed, not take more or less than indicated and take the drug only when the doctor or dentist decides to take it.

The recommended dose of prophylactic antibiotics for surgery has varied with the studies. It was common to give a dose of antibiotics when the patient was called to the operating room and to continue with the drug for 48 hours after the surgery.

More recent studies indicate that a single dose of Antibiotic administered immediately before the start of surgery can effectively prevent infection while reducing the risk of side effects.

Precautions in Antibiotic Prophylaxis

The warnings listed below refer mainly to the effects of drugs when taken in multiple doses.

When prophylactic antibiotics are used as a single dose, adverse effects are implausible. The only exceptions are for people who are allergic to the Antibiotic used.

People who are allergic to penicillin should avoid cephalosporin antibiotics. If the medication causes nausea, vomiting, or diarrhea, the patient is advised to consult with the doctor or dentist who prescribed it as soon as possible.

Patients taking antibiotics before surgery should not wait until the day of surgery to report problems with the medication. The doctor or dentist needs to know immediately if side effects occur.

Side effects

Antibiotics can cause a series of side effects. For more details, the patient is recommended to read the indications written on certain types of antibiotics.

Anyone with unusual or worrisome symptoms should contact the prescribing doctor after taking antibiotics.


Antibiotics can interact with other medications, whether used to treat or prevent infection. When this happens, the effects of one or both drugs can change or increase the risk of side effects.

Anyone who takes antibiotics for any reason should inform the doctor about all the other medications they are taking and ask if taking them can interfere with the effects of the drugs.

For details on interactions between medications, it is advisable to read the instructions written on certain types of antibiotics.