Common brand name: Cleocin

Description: Clindamycin is a broad-spectrum antibiotic. It works particularly well against certain types of bacteria.

Dental uses: This drug has three main uses in dentistry.

First, it is used in people who are allergic to penicillins and at risk to develop endocarditis. This is a serious heart infection. It can be fatal. People at risk for this bacterial infection take antibiotics before dental treatments that tend to cause bleeding. People at risk include those who have:

• Artificial heart valves
• A history of endocarditis
• Certain forms of congenital heart disease
• A heart transplant that has valve disease

Bleeding can occur in treatments that:

• Puncture or cut into mouth tissue
• Manipulate the gums or the area around a tooth root

Clindamycin is used in place of amoxicillin in at-risk patients who are allergic to penicillin and related drugs.

Second, clindamycin is used to help prevent joint infections in certain people with artificial joints of the hip, knee and elbow.

Third, it is prescribed for people with dental abscesses in bone and soft tissue that don't respond well to penicillin VK. Oral surgeons and endodontists often prescribe it for long-lasting infections in bone.

Dosages for dental purposes: To prevent endocarditis or joint infection, the dose is 600 milligrams (4 tablets of 150 milligrams each). It should be taken 30 to 60 minutes before a dental treatment likely to cause bleeding. Patients generally tolerate the one-dose regimen well. For oral infections or abscesses, the dose is 150 milligrams to 300 milligrams every 6 to 8 hours. It should be taken for at least 5 to 7 days.

Concerns and possible side effects: Diarrhea and abdominal pain are more common with clindamycin than with penicillin VK. Occasionally, people treated with clindamycin or other antibiotics develop a severe form of bloody, mucus-filled diarrhea. This is known as pseudomembranous colitis. It can occur during or after antibiotic treatment. It is caused by excess growth of Clostridium difficile bacteria in the intestines. These bacteria are resistant to clindamycin. People with this type of diarrhea must be treated with other antibiotics in a hospital.

This type of diarrhea is not common with the dental use of clindamycin. However, it occurs more often in people who are elderly, have a history of colitis, or take clindamycin for a long time.

The clindamycin label contains a "black box" warning. It says that this drug can cause severe and possibly fatal colitis. If you have diarrhea while taking clindamycin or up to several weeks afterward, contact your dentist or physician right away.