Synercid is a combination antibiotic that fights severe or life-threatening infection caused by bacteria.

Synercid is used to treat severe infections of the skin or other body systems.

Synercid may also be used for purposes not listed in this medication guide.

Follow all directions on your medicine label and package. Tell each of your healthcare providers about all your medical conditions, allergies, and all medicines you use.

Synercid is injected into a vein through an IV, sometimes with an infusion pump or through a central IV or "PICC" line.

This medicine is most often given in a hospital setting. However, you may be shown how to use an IV at home. Do not give yourself this medicine if you do not understand how to use the injection and properly dispose of needles, IV tubing, and other items used.

Synercid must be given slowly, and the infusion can take at least 1 hour to complete.

Call your doctor at once if you have problems with your IV, or if the medicine does not flow freely from the IV bag through the tubing.

Synercid is usually given for at least 7 days. Follow all directions on your prescription label. Do not use this medicine in larger or smaller amounts or for longer than recommended.

Use this medicine for the full prescribed length of time. Your symptoms may improve before the infection is completely cleared. Skipping doses may also increase your risk of further infection that is resistant to antibiotics. Synercid will not treat a viral infection such as the flu or a common cold.

If you keep this medicine at home, store the IV bag a refrigerator and use it before the expiration date on medicine label. Do not freeze.

You should not use Synercid if you are allergic to it.

To make sure Synercid is safe for you, tell your doctor if you have ever had:

• an allergic reaction to any antibiotic;

• liver disease; or

• kidney disease.

It is not known whether Synercid will harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant.

It is not known whether dalfopristin and quinupristin passes into breast milk or if it could affect the nursing baby. Tell your doctor if you are breast-feeding.

Call your doctor for instructions if you miss a dose of Synercid.

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

Overdose can cause vomiting, trouble breathing, tremors, and loss of balance or coordination.

Antibiotic medicines can cause diarrhea, which may be a sign of a new infection. If you have diarrhea that is watery or bloody, call your doctor. Do not use anti-diarrhea medicine unless your doctor tells you to.

Get emergency medical help if you have signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Synercid may cause serious side effects. Call your doctor at once if you have:

• severe stomach pain, diarrhea that is watery or bloody;

• pain, bruising, swelling, or severe irritation around the IV needle;

• jaundice (yellowing of the skin or eyes);

• a seizure (convulsions);

• irregular heart rate; or

• sudden numbness or weakness, severe headache, slurred speech, problems with balance.

Common side effects of Synercid may include:

• mild irritation around the IV needle;

• rash; or

• nausea.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Many drugs can interact with Synercid. Not all possible interactions are listed here. Tell your doctor about all your current medicines and any you start or stop using, especially:

• methylprednisolone;

• carbamazepine;

• antiviral medicine to treat HIV/AIDS--delavirdine, indinavir, nevirapine, ritonavir;

• cancer medicine--docetaxel, paclitaxel, vinblastine, vincristine;

• heart or blood pressure medication--diltiazem, nifedipine, verapamil;

• medicine to prevent organ transplant rejection--cyclosporine, tacrolimus;

• a sedative--diazepam (Valium), midazolam; or

• "statin" cholesterol medication--atorvastatin, lovastatin, simvastatin, Zocor, Vytorin, Crestor, and others.

This list is not complete and many other drugs can interact with Synercid. This includes prescription and over-the-counter medicines, vitamins, and herbal products. Give a list of all your medicines to any healthcare provider who treats you.