Ceftolozane and tazobactam is a combination antibiotic that is used to treat certain bacterial infections of the lungs, stomach, or urinary tract.

Ceftolozane and tazobactam is sometimes given in combination with another antibiotic medicine.

Ceftolozane and tazobactam 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.

Follow all directions on your prescription label and read all medication guides or instruction sheets. Use the medicine exactly as directed. This medicine is sometimes given for up to 14 days, depending on the type of infection being treated.

Ceftolozane and tazobactam is given as an infusion into a vein. A healthcare provider will give your first dose and may teach you how to properly use the medication by yourself.

Read and carefully follow any Instructions for Use provided with your medicine. Ask your doctor or pharmacist if you don't understand all instructions.

Prepare an injection only when you are ready to give it. Do not use if the medicine has changed colors or has particles in it. Call your pharmacist for new medicine.

Ceftolozane and tazobactam must be mixed with a liquid (diluent) and then further diluted with another liquid in an IV bag. When using injections by yourself, be sure you understand how to properly mix and store the medicine.

Use this medicine for the full prescribed length of time, even if your symptoms quickly improve. Skipping doses can increase your risk of infection that is resistant to medication. Ceftolozane and tazobactam will not treat a viral infection such as the flu or a common cold.

Store the unmixed ceftolozane and tazobactam powder in a refrigerator. Protect from light.

After you mix the powder with the first diluent, store this mixture at room temperature for up to 1 hour before further mixing it into the IV bag.

Medicine mixed in an IV bag must be used within 24 hours if you keep it at room temperature, or within 7 days if kept in a refrigerator. Throw away any unused mixture that has not been used within these times.

Do not freeze the mixed or unmixed medicine.

Each vial (bottle) is for one use only. Throw it away after one use, even if there is still medicine left inside.

Use a needle and syringe only once and then place them in a puncture-proof "sharps" container. Follow state or local laws about how to dispose of this container. Keep it out of the reach of children and pets.

You should not use ceftolozane and tazobactam if you are allergic to ceftolozane or tazobactam, or if you are allergic to similar antibiotics, such as:

• penicillin antibiotics--amoxicillin, ampicillin, dicloxacillin, oxacillin, penicillin, ticarcillin, Amoxil, Moxatag, Augmentin, Principen, and others; or

• cephalosporin antibiotics--cefdinir, cefprozil, cefuroxime, cephalexin, Ceftin, Cefzil, Keflex, Omnicef, and others.

Tell your doctor if you have ever had:

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

Tell your doctor if you are pregnant or breastfeeding.

Call your doctor for instructions if you miss a dose of ceftolozane and tazobactam.

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

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 before using anti-diarrhea medicine.

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

Ceftolozane and tazobactam may cause serious side effects. Call your doctor at once if you have:

• severe stomach pain;

• diarrhea that is watery or bloody (even if it occurs months after your last dose);

• kidney problems--little or no urination, swelling in your feet or ankles, feeling tired or short of breath; or

• symptoms of bleeding in the brain--sudden numbness or weakness, problems with vision or speech.

Side effects may be more likely in older adults.

Common side effects of ceftolozane and tazobactam may include:

• nausea, diarrhea;

• headache;

• fever;

• kidney problems; or

• abnormal liver function tests.

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.

Other drugs may affect ceftolozane and tazobactam, including prescription and over-the-counter medicines, vitamins, and herbal products. Tell your doctor about all your current medicines and any medicine you start or stop using.