Clarithromycin (Biaxin)

What Is Clarithromycin?

Clarithromycin is an antibiotic drug. In the US, its brand name is Biaxin®. In other countries it is known as Klacid and Mavid. Antibiotics fight infections caused by bacteria. Clarithromycin is also used to fight opportunistic infections in people with HIV. Abbott manufactures it.

Why Do People With HIV Take Clarithromycin?

Clarithromycin is used for mild or moderate bacterial infections. It works against several different bacteria, especially chlamydia, hemophilus and streptococcus. These bacteria can infect the skin, nose, throat, lungs and ears.

Many germs live in our bodies or are common in our surroundings. A healthy immune system can fight them off or keep them under control. However, HIV infection can weaken the immune system. Infections that take advantage of weakened immune defenses are called "opportunistic infections." People with advanced HIV disease can get opportunistic infections. See Fact Sheet 500 for more information on Opportunistic Infections. Some people with very low CD4 cell counts (below 50) take clarithromycin to prevent infections. See Fact Sheet 124 for more information on CD4 cells.

One opportunistic infection in people with HIV is MAC. This stands for Mycobacterium avium complex. See Fact Sheet 514 for more information on MAC. People who have a CD4 cell count of less than 50 may develop MAC.

Clarithromycin is often used with other antibiotics to treat MAC. It can also be used to prevent MAC infection. If your CD4 cell count is below 50, talk to your health care provider about using clarithromycin.

Some people are allergic to clarithromycin and similar antibiotics. Be sure to tell your health care provider if you are allergic to erythromycin or other antibiotics.

What About Drug Resistance?

Whenever you take medication, be sure to take all of the prescribed doses. Many people stop if they feel better. This is not a good idea. If the drug doesn't kill all of the germs, they might change (mutate) so that they can survive even when you are taking medications. When this happens, the drug will stop working. This is called "developing resistance" to the drug.

For example, if you are taking clarithromycin to fight MAC and you miss too many doses, the MAC in your body could develop resistance to clarithromycin. Then you would have to take a different drug or combination of drugs to fight MAC.

How Is Clarithromycin Taken?

Clarithromycin is available in tablets of 250 or 500 milligrams (mg). It is also available in granules to prepare a liquid form. The dose and the length of time you will take it depend on the type of infection you have.

The dose used to prevent MAC infection is 500 mg every 12 hours. The treatment continues as long as your CD4 cell count is low enough for you to develop MAC. If your CD4 cell count goes above 100 for 3 to 6 months, your health care provider may recommend stopping clarithromycin.

Regular clarithromycin tablets can be taken with or without food. There is also "Biaxin XL" which is an extended release version. Biaxin XL should be taken with food. Taking Biaxin with food can reduce stomach upset.

Take clarithromycin with a full glass of water.

What Are the Side Effects?

The side effects of clarithromycin mostly affect the digestive system. They include diarrhea, nausea, heartburn and pain in the abdomen. Some people get headaches or rash. Very few people who take clarithromycin get these side effects. However, most anti-HIV medications also cause problems in the digestive system. Clarithromycin could make those problems worse.

Clarithromycin can be hard on the liver. Your health care provider will probably watch your lab results carefully for any sign of liver damage. Let your health care provider know if your urine gets dark or your bowel movements get light-colored.

Antibiotics kill some helpful bacteria that normally live in the digestive system. You can eat yogurt or take supplements of acidophilus to replace them.

How Does Clarithromycin React With Other Drugs?

Clarithromycin is broken down by the liver. It can interact with other drugs that also use the liver. Scientists have not yet studied all the possible interactions. Clarithromycin probably interacts with all of the non-nucleoside reverse transcriptase inhibitors (NNRTIs), some blood thinners, heart medications, seizure medications, and other antibiotics. Be sure your health care provider knows about all the medications and supplements you are taking.

The protease inhibitors ritonavir (Norvir), lopinavir (Kaletra) and darunavir (Prezista) can increase blood levels of clarithromycin.

Clarithromycin may change blood levels of zidovudine (AZT, Retrovir).