Piperacillin is a penicillin antibiotic that fights bacteria in the body.

Tazobactam is an antibiotic similar to a penicillin that fights bacteria in the body.

The combination of piperacillin and tazobactam is used to treat many different infections caused by bacteria, such as urinary tract infections, bone and joint infections, severe vaginal infections, stomach infections, skin infections, and pneumonia.

This medication is sometimes given together with other antibiotics.

Piperacillin and tazobactam may also be used for purposes not listed in this medication guide.

You should not use this medication if you are allergic to piperacillin and tazobactam or to any other penicillin antibiotic, such as amoxicillin (Amoxil, Augmentin, Dispermox, Moxatag), ampicillin (Principen, Unasyn), dicloxacillin (Dycill, Dynapen), oxacillin (Bactocill), ticarcillin (Timentin), or penicillin (Bicillin L-A, PC Pen VK, Pfizerpen), and others.

Before using piperacillin and tazobactam tell your doctor if you have kidney disease, a bleeding or blood clotting disorder, low levels of potassium in your blood, cystic fibrosis, a history of allergies, if you are on a low-salt diet, or if you are allergic to a cephalosporin antibiotic such as cefdinir (Omnicef), cefprozil (Cefzil), cefuroxime (Ceftin), cephalexin (Keflex), and others.

Use this medication 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. Piperacillin and tazobactam will not treat a viral infection such as the common cold or flu.

Piperacillin and tazobactam may cause bleeding, especially in people with kidney disease or using certain medicines. Tell your doctor if you are using any medication to prevent blood clots such as alteplase (Activase), bivalirudin (Angiomax), clopidogrel (Plavix), dabigatran (Pradaxa), dipyridamole (Persantine, Aggrenox), enoxaparin (Lovenox), fondaparinux (Arixtra), heparin, tenecteplase (TNKase), ticlopidine (Ticlid), tinzaparin (Innohep), warfarin (Coumadin, Jantoven), and others.

You should not use this medication if you are allergic to piperacillin and tazobactam or to any other penicillin antibiotic, such as:

• amoxicillin (Amoxil, Augmentin, Dispermox, Moxatag);

• ampicillin (Principen, Unasyn);

• dicloxacillin (Dycill, Dynapen);

• oxacillin (Bactocill);

• ticarcillin (Timentin); or

• penicillin (Bicillin L-A, PC Pen VK, Pfizerpen), and others.

To make sure you can safely use piperacillin and tazobactam, tell your doctor if you have any of these other conditions:

• kidney disease (or if you are on dialysis);

• a bleeding or blood clotting disorder;

• an electrolyte imbalance such as low levels of potassium in your blood;

• cystic fibrosis;

• a history of any type of allergy;

• if you are on a low-salt diet; or

• if you are allergic to a cephalosporin antibiotic such as cefdinir (Omnicef), cefprozil (Cefzil), cefuroxime (Ceftin), cephalexin (Keflex), and others.

FDA pregnancy category B. Piperacillin and tazobactam is not expected to be harmful to an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant during treatment.

Piperacillin and tazobactam may pass into breast milk and could harm a nursing baby. Do not use this medication without telling your doctor if you are breast-feeding a baby.