This medication is a combination of 2 antibiotics. It is used to treat certain serious bacterial infections that have not responded to treatment with other antibiotics (resistant infections). This medication belongs to the class of antibiotics called streptogramins. Quinupristin/dalfopristin works by stopping the growth of bacteria.

This medication is given by injection into a vein as directed by your doctor, usually 2 to 3 times daily (every 8 to 12 hours). It should be injected slowly over 1 hour. The dosage is based on your medical condition, body weight, and response to treatment.

If you are giving this medication to yourself at home, learn all preparation and usage instructions from your health care professional. Before using, check this product for particles or discoloration. If either is present, do not use the liquid. Learn how to store and discard medical supplies safely.

For the best effect, use this antibiotic at evenly spaced times. To help you remember, use this medication at the same time(s) every day.

Continue to use this medication for the full time prescribed, even if symptoms disappear after a few days. Stopping the medication too early may result in a return of the infection.

Tell your doctor if your condition lasts or gets worse.

Nausea, vomiting, diarrhea, and headache may occur. If any of these effects last or get worse, tell your doctor or pharmacist promptly.

Remember that this medication has been prescribed because your doctor has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.

Tell your doctor right away if you develop redness/swelling/pain/warming of the skin at the injection site. Flushing the IV line after each dose of this medication with dextrose 5 percent in water solution as directed will reduce the risk of vein irritation.

Tell your doctor right away if you have any serious side effects, including:

• joint/muscle pain
• yellowing eyes/skin
• blood in the urine

Get medical help right away if you have any very serious side effects, including:

• chest pain

This medication may rarely cause a severe intestinal condition due to a bacteria called C. difficile. This condition may occur during treatment or weeks to months after treatment has stopped. Tell your doctor right away if you develop:

• diarrhea that doesn't stop
• abdominal or stomach pain/cramping
• blood/mucus in your stool

If you have these symptoms, do not use anti-diarrhea or opioid products because they may make symptoms worse.

Use of this medication for prolonged or repeated periods may result in oral thrush or a new vaginal yeast infection. Contact your doctor if you notice white patches in your mouth, a change in vaginal discharge, or other new symptoms.

A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including:

• rash
• itching/swelling (especially of the face/tongue/throat)
• severe dizziness
• trouble breathing

This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.

In the US - Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch.

In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

Before using quinupristin/dalfopristin, tell your doctor or pharmacist if you are allergic to it; or to other streptogramin antibiotics (such as pristinamycin, virginiamycin); or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.

Before using this medication, tell your doctor or pharmacist your medical history, especially of:

• liver problems
• high levels of bilirubin in the blood (hyperbilirubinemia)

This medication may cause live bacterial vaccines (such as typhoid vaccine) to not work well. Tell your health care professional that you are using this medication before having any immunizations/vaccinations.

Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).

During pregnancy, this medication should be used only when clearly needed. Discuss the risks and benefits with your doctor.

It is unknown if this drug passes into breast milk. Consult your doctor before breastfeeding.

See also How to Use.

Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval.

This medication can slow down the removal of other medications from your body, which may affect how they work. Examples of affected drugs include certain antiarrhythmic drugs (such as amiodarone, disopyramide, quinidine), cyclosporine, certain macrolide antibiotics (such as erythromycin, clarithromycin), certain antipsychotics (such as haloperidol, pimozide), among others.

If someone has overdosed and has serious symptoms such as passing out or trouble breathing, call 911. Otherwise, call a poison control center right away. US residents can call 1-800-222-1222. Canada residents can call 1-844-764-7669.

Lab and/or medical tests (such as liver function) should be done while you are using this medication. Keep all medical and lab appointments. Consult your doctor for more details.

It is important to get each dose of this medication as scheduled. If you miss a dose, ask your doctor or pharmacist right away for a new dosing schedule. Do not double the dose to catch up.

Consult the product instructions and your pharmacist for storage details. Keep all medications away from children and pets.

Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company.