Antibiotics are medications used to treat infectious diseases that result from bacteria. Antibiotics include well-known medications such as penicillin (one of the earliest antibiotics) and erythromycin. They are often given to patients with certain types of valvular heart disease prior to surgical or dental procedures to help prevent infection in and around the heart muscle. 

In the past, antibiotics have been routinely recommended to prevent bacterial infections of the heart before dental procedures. In 2007, however, the American Heart Association issued revised guidelines for the use of preventive antibiotics before dental procedures. According to the new guidelines, most people who were taking antibiotics no longer need them. The only people who are currently advised to get preventive antibiotic treatment before common dental procedures are those at risk for bad outcomes due to infective endocarditis, or a bacterial infection of the innermost layer of heart tissue.

Antibiotics, however, are still crucial in the treatment of bacterial infections of the heart that may cause endocarditis, myocarditis, pericarditis, all of which are inflammation of different layers of the heart and valves. If a patient suffers from one of these conditions, and the condition is caused by bacterial infection, they will be prescribed powerful antibiotics.

Antibiotics, which are commonly taken either orally or intravenously, only attack bacterial infection. They have no effect on viruses,fungal infections or parasites. Antibiotics are created completely or partially from certain microorganisms. In some cases, the antibiotics kill the bacteria directly. In other cases, they prevent the bacteria from reproducing, allowing the immune system to destroy any remaining bacteria.

Different antibiotics or combination of drugs may be used to treat various conditions. It is important for individuals to take all of their prescribed antibiotics, even if their symptoms improve after only a few days. Otherwise, the bacteria are only weakened instead of totally destroyed. The weakened bacteria can change (mutate) and re-attack the patient. Whenever the bacteria change form, the patient is at increased risk of being infected by a strain of bacteria that is resistant to the antibiotic they have been given. This antibiotic resistance has become a worldwide problem with the emergence of bacteria strains that are resistant to all but the strongest antibiotics.

In addition to taking all of one's prescribed antibiotics, the general public is urged to avoid “antibacterial” soaps and similar products, which have been shown to increase bacterial resistance. In hospitals, however, antibacterial gel has been shown to reduce in-hospital acquired infections, a major source of illness.

Although antibiotics can treat many diseases, they can occasionally cause side effects, including gastrointestinal problems. In addition, antibiotics can interact with other drugs and medications. They can reduce the effectiveness of certain medications (e.g. birth control pills, antacids) and increase the effect of others (e.g., anticoagulants, bronchodilators). Patients should tell their physician about all prescription medications, over-the-counter drugs, herbal remedies and vitamin supplements that they are taking when antibiotics are prescribed.

Antibiotics are medications used to fight bacterial infections; they will not harm viruses, fungal infections or parasites. Antibiotics are usually taken orally in pill form, but can be administered through intravenous injection (into a vein), intramuscular injection (into a muscle, to treat skin infections) or as a skin ointment. There are many types of antibiotics and some have proven to be more effective than others at treating specific types of infection. "Broad spectrum" antibiotics are medications that harm or kill a wide variety of infectious bacterial agents.

About 90 percent of the antibiotics used today are created by chemically isolating them from bacteria, although a few are completely manufactured.  Antibiotics are used both to treat bacterial infection of the heart, and in limited cases, to prevent bacterial infection. Some of the antibiotics that may be used for these purposes include:

Antibiotics harm microorganisms in a variety of ways. Most antibiotics fall into one of the following categories:

A number of researchers have studied possible links between bacteria and heart disease. For example, one theory speculates that low-level infection of the coronary arteries with chlamydia pneumoniae (a type of pneumonia) may accelerate atherosclerosis and increase risk for heart attack. Other researchers have looked at the role of periodontal bacteria, which can enter the bloodstream through tiny cuts in the gums and travel through the body. These periodontal bacteria have been discovered in the heart, although the newest studies show that the risk of contracting an acute infection from these bacteria is very low. Rather, some researchers believe that their chronic presence in the heart may hasten the development of atherosclerotic heart disease.

The underlying factor that might explain why bacterial infection raises the risk of atherosclerosis or hastens its development is inflammation. In response to the bacterial infection, the body mounts an immune system response that is characterized by the release of inflammatory chemicals. These chemicals are the same ones that cause inflammation of the artery wall in atherosclerosis. By increasing the inflammatory load throughout the body, it is possible that bacterial infection may directly contribute to atherosclerosis. While this is a tantalizing possibility, however, studies have not shown that therapy with antibiotics can reduce the risk of heart attack.

In fact, even the widespread use of preventive antibiotics in oral surgery and dental procedures has not been conclusively proven in a well-designed, double-blinded study to reduce the risk of endocarditis. As a result, the American Heart Association in 2007 revised its guidelines for the use of antibiotics before common dental procedures. Today, only patients at high risk of bad outcomes from infective endocarditis, an infection of the endocardium, are advised to take antibiotics.

Antibiotics may be used to treat a variety of bacterial infections, including heart infections such as bacterial endocarditis. Endocarditis is an infection in vulnerable areas of the endocardium, the innermost layer of the heart chambers and valves. It often affects individuals with existing valvular heart disease, congenital defects, artificial valves, or intravenous (I.V.) drug abusers.

Infections may be caused by bacteria released into the bloodstream as a result of surgical or dental procedures, I.V. drug abuse, or from infections in other parts of the body (e.g., pneumonia; urinary tract infections).

Previous guidelines advocated that individuals who were at a high risk for endocarditis take antibiotics before any dental or medical procedure. It was thought that this preventive action may help to protect patients from bacteria that could be introduced into the bloodstream.

However, in 2007, the American Heart Association issued revised guidelines suggesting that prophylactic antibiotics before medical or dental procedures were not necessary for most patients at risk for endocarditis. These new guidelines are based on several studies that have produced no conclusive evidence to show that prophylactic antibiotic use reduced the risk of bacterial endocarditis. Additionally, the extensive use of antibiotics among heart patients resulted in concerns that these patients may develop drug-resistant strains of bacteria.

As part of the revised guidelines, antibiotics may still be used before certain medical and dental procedures for the following groups:

• Patients with prosthetic heart valves
  
• Patients with a history of endocarditis
  
• Patients with certain congenital heart defects, including those who have repaired defects under certain conditions
  
• Heart transplant recipients

Patients who have mild or asymptomatic heart conditions, such as mitral valve prolapse, are no longer advised to take antibiotics before dental procedures. Additionally, patients who have suffered from rheumatic fever, or who have connective tissue disorders such as Marfan syndrome, are no longer advised to take antibiotics before dental procedures.

Antibiotics are generally safe but can produce reactions and even serious medical complications in some individuals. Patients should contact their physician immediately if they experience any of the following:

Other possible complications include kidney failure, liver abnormalities and pseudomembranous colitis. This is a condition caused by the killing of “good” bacteria by antibiotics, thus allowing for the growth of another bacterium, Clostridium difficile. This bacterium is responsible for watery and bloody diarrhea, fever and abdominal pain. Pseudomembranous colitis is treated with an antibacterial drug such as metronidazole or vancomycin.

Patients should consult their physician before taking any other medication (either prescription or over-the-counter), nutritional supplements or herbal remedies. Of particular concern to individuals taking antibiotics are:

Vaginal yeast infections are a common side effect of some antibiotics because they can cause an overgrowth of normal body organisms such as yeast. This can be avoided by daily consumption of “live culture” yogurt (available at any grocery store) while undergoing antibiotic therapy.

Symptoms usually lessen two to three days after starting oral antibiotic treatment. However, patients need to continue taking the remainder of their medication. Unless all of the bacteria are completely killed, the bacteria can change into another form and produce symptoms again. Furthermore, the change (mutation) of the bacteria increases the risk of being infected by bacteria that are more difficult to kill with antibiotics. This is known as antibiotic resistance, and it is a worldwide healthcare concern. Antibiotic-resistant strains of bacteria already exist and new ones are created daily. Patients can help to slow the creation of resistant strains by:

Preparing questions in advance can help patients to have more meaningful discussions with their physicians regarding their conditions. Patients may wish to ask their doctor or healthcare professional the following antibiotics-related questions:

1. For which procedures should I be taking antibiotics?
   
   
2. When should I start taking them and for how long?
   
   
3. Which antibiotics are best for my condition?
   
   
4. If one type does not work, will I be switched to a different one?
   
   
5. Is there an antibiotic that offers fewer side effects?
   
   
6. Are there any foods or beverages that will affect the function of this antibiotic?
   
   
7. Am I using any other drugs that will interfere with the antibiotic?
   
   
8. Will the antibiotic reduce the effectiveness of any of my current medications?
   
   
9. How will I know if I have an allergic reaction to the antibiotic?
   
   
10. What can I take if I am allergic to penicillin?
    
    
11. How long should I take the antibiotic after the procedure?
    
    
12. Should I keep some antibiotics on hand just in case I need them?