Quinupristin and Dalfopristin (Intravenous)

Quinupristin and dalfopristin are more effective when paired together, and are used to treat serious infections which may not respond to other medication.


Quinupristin and dalfopristin are two separate antibiotics usually combined into one medicine in order to combat serious infections of the blood and the skin, especially those that are not affected by other kinds of antibiotics or medication. These infections may be life-threatening. The drugs work in synergy to produce an effect far better than when they are used alone.

Quinupristin and dalfopristin belong to a group of antibiotics known as streptogramins. Antibiotics primarily work by stopping the growth of bacteria. They do not work on infections of other kinds, such as viral infections like colds or the flu. When using antiobiotics, it is necessary that patients finish the entire course of treatment. Partial treatments or unnecessary prescriptions may end up with surviving bacteria that develop resistance against the medicine, and therefore lead to even more serious infections in the future.

The medicine usually comes in the form of a powder, which is then added to a liquid and then injected into a patient. Infusion is slow, taking about an hour, and must be administered twice to thrice daily, at evenly spaced intervals so that there is a constant presence of the drug in the body.

Treatment is usually given at a hospital or a clinic, by a qualified professional such as a doctor or nurse. However, the patient may also receive treatment at home, in which case the person administering the medicine must be familiar with the procedure, whether it is the patient themselves or a caregiver. Quinupristin and dalfopristin are prescription drugs, meaning that they are only available if a doctor has prescribed them.

Conditions Treated

  • Bacterial infections

Type of Medicine

  • Antibiotics

Side Effects

With any drug taken, there is a chance of side effects. Not all patients will definitely encounter side effects. However, if the patient notices any symptoms, they should tell their doctor. In more serious cases, they may need to seek immediate medical treatment. While there are considerable effects to using the medication, it is usually prescribed if the doctor has judged the benefits of the medicine to outweigh the negative effects that may happen during treatment.

More common side effects include:

  • Nausea
  • Vomiting
  • Diarrhea
  • Headaches
  • Irritation at site of injection which may show as skin redness, warmth, swelling or pain

If the patient experiences the following more serious side effects to the medication, they should call their doctor right away:

  • Yellowed eyes or skin
  • Blood in the urine
  • Pain in joints or muscles
  • Pain in chest

Prolonged or repeated use of quinupristin and dalfopristin may result in either oral thrush or a vaginal infection. The patient may notice:

  • White patches in the mouth
  • Unusual discharge from the vagina

Quinupristin and dalfopristin may also lead to a serious intestinal condition, which causes diarrhea. It may happen while the patient is undergoing treatment, or even up to weeks after the treatment has ended. The patient should avoid using anti-diarrhea or narcotic pain medication if they develop this side effect, as it may worsen their condition. The symptoms of this infection include:

  • Blood or mucus in stools
  • Persistent diarrhea
  • Pain or cramping in the stomach or abdominal area

An allergic reaction to quinupristin and dalfopristin is rare. However, the patient should be careful to take note of any of the following symptoms:

  • Swelling or itching, especially in the face, throat and tongue
  • Hives
  • Rashes
  • Dizziness
  • Trouble with breathing

The above is an incomplete list of side effects that may happen with using quinupristin and dalfopristin. If the patient encounters any side effects that are not listed above, they should inform their doctor as soon as possible.


Quinupristin and dalfopristin comes in a powder form that needs to be infused into a liquid before being injected. It is usually injected by a doctor, or a qualified healthcare giver, at a hospital or clinic, but it may also be administered at home. If treatment is carried out at home, the patient or caretaker must understand and follow the doctor's instructions clearly. They should make sure that any doubts or questions that they have are resolved before they begin treatment. The doctor or a nurse will show them how to infuse and inject the medicine beforehand.

Prior to injection, the patient or their caretaker should check the medicine visually to ensure that there is no discoloration, specks, or any other form of contamination. If contamination is visible, they should discard that particular dose and use another.

It is advisable for the patient to receive the medication at the same time every day, so that they do not miss a dose. In the event of a missed dose, they should take it as soon as possible. However, if the timing is too close to the next dose, they should skip the previous one and simply resume the second dosage. If they are unsure or if there is more than one missed dose, the patient should seek medical advice.

The dosage will vary based on the patient and their needs. One dose takes about an hour to be slowly injected, or infused, into the patient, and the timing varies from two to three times a day, spaced about 8 to 12 hours apart.

After a few days, the patient may begin to feel better. However, it is essential that the full course of treatment prescribed be finished. If the patient does not finish the course of antibiotics, it may lead to further bacterial growth, and they may increase their personal risk of contracting an even more serious case of infection in the future.

Quinupristin and dalfopristin should not be infused more quickly than has been prescribed. The patient should also not use more, or less, of the prescribed medicine. Misuse of the medicine may lead to an increased change of unwanted side effects or a decrease in the effectiveness of the medication.

A 5% dextrose solution in water may be used as a flush after injection to minimise irritation. Saline and heparin should not be used as they are incompatible with quinupristin and dalfopristin.

While the patient is undergoing treatment, the doctor will check on their progress regularly to ensure that the medicine is having the desired effects. If not, blood tests may be required to check for unwanted side effects.

In the case of an overdose, the patient or someone else should call for emergency treatment. They may call a local hospital or a local poison control center. Signs of an overdose may include:

  • Trouble breathing
  • Tremors, or uncontrolled shaking of a part of the body
  • Lack of coordination
  • Vomiting


Quinupristin and dalfopristin may interact with other drugs or supplements to produce unwanted effects. Certain medications should not be mixed, but they may be taken together if the doctor feels that it is necessary to do so. They may adjust the dosage of the medications or take other precautions in those cases.

Alcohol and tobacco generally should not be taken during or around the time of using a medication. The patient may want to ask their doctor about possible interactions with their medication. Certain foods and drink may also affect the use of their medicine.

Before starting a course of quinupristin and dalfopristin, the patient should note down any other drugs, supplements or herbal products they are using (or have recently used), and let their doctor know. They should also inform their doctor as to any allergies they may have. This includes allergies to drugs, food, dyes, preservatives, animal or herbal products. Patients should not start or stop the consumption of any medications or supplements without the knowledge or consent of their doctor, nor should they abruptly change the amount or dosage.

The following is a non-exhaustive list of possible drug interactions with quinupristin and dalfopristin:

  • Amiodarone
  • Disopyramide
  • Quinidine
  • Cyclosporine
  • Cisapride
  • Erythromycin
  • Clarithromycin
  • Haloperidol
  • Pimozide
  • Astemizole
  • Diazepam
  • Tacrolimus
  • Vinblastine
  • Vinorelbin

If the patient has certain existing medical problems, they may interfere with the effect of quinupristin and dalfopristin. The doctor should be informed about them prior to prescribing the medicine. These conditions include:

The use of quinupristin and dalfopristin may affect the rate of removal of other drugs from the body. These include certain macrolide antibiotics, anti-psychotic medication and anti-arrhythmnic medications. They may also decrease the effectiveness of certain forms of birth control, so if the patient has any plans regarding pregnancy and birth control, they should inquire further with their doctor or pharmacist.


Before starting treatment with quinupristin and dalfopristin, the patient is required to let their doctor know their medical history, especially if they have had liver problems or high levels of bilirubin in their blood. They should also disclose if they are allergic to anything, including an allergy to the medicine.

The patient should not start or stop any medication or supplements, whether they are prescription or over-the-counter, without discussing it with their doctor.

Use of quinupristin and dalfopristin may cause diarrhea. This may happen while taking quinupristin-dalfopristin, or even up to eight weeks after usage of the medicine has ended. Mild diarrhea should go away by itself. However, if it persists or becomes worse, the patient will need to seek medical advice. They should not take medication to stop the diarrhea as it may interact with the drugs.

There is currently insufficient information on the use of quinupristin and dalfopristin with children aged 16 years and younger. As such, it is unknown how safe or efficient the medicine may be with these inidividuals.

Elderly adults are not expected to have problems with quinupristin and dalfopristin. However, there have been, to date, little studies performed in regards to geriatric problems interacting with the drugs.

For pregnant or breastfeeding patients, there is little information on how quinupristin and dalfopristin interact with and affect infants and unborn babies. While it is unlikely that the medicine will affect unborn babies, pregnant or breastfeeding patients may wish to consult with their doctors on the benefits and risks of using quinupristin and dalfopristin. Patients intending to become pregnant should also discuss the plans with their doctor prior to starting treatment.


The doctor or primary healthcare provider will give instructions on how to store the medication properly. The patient or their caretaker should make sure that they understand the instructions thoroughly, and follow them closely. If they have any doubts, they should clarify them with the doctor.

If the medicine is expired or no longer needed, it should be disposed of through proper channels. It should not be flushed down the toilet bowl, nor should it be disposed of in a manner where children or animals may get to it. The doctor or local waste management will be able to advise on how to handle the unwanted medication.


Certain life-threatening skin or blood infections caused by bacteria may not respond to treatment with other drugs. Quinupristin and dalfopristin are usually prescribed in these cases to help combat these infections. Because they work better when paired together, they are used as a single medication, in the form of a powder that is then added to a liquid to be infused into the patient.

The patient is likely to receive treatment at a hospital or clinic, with injection performed by a doctor or a nurse. The process takes about an hour as the medicine needs to be fed intravenously in a continuous and slow manner. Doses are spread throughout the day at equal intervals. This is to ensure a constant presence of quinupristin and dalfopristin in the body, which will help to fight the infection. A faster drip rate or an increased dosage of the medicine will not help the condition and may even increase the risk of side effects.

Alternatively, the patient may choose to receive treatment at home. In this case, they, or a caregiver, are required to be familiar with the procedure in order to give the medicine safely.

Patients are required to give a list of their allergies and any pre-existing medical conditions to their doctor prior to starting treatment with quinupristin and dalfopristin in the case of any drug interactions. The use of this medication may interact badly with existing conditions like liver disease, and may also cause a new infection which leads to diarrhea.

However, as it is used to treat severe bacterial infections, quinupristin and dalfopristin are prescribed if the doctor feels that the treatment will be successful, and that the positive effects will outweigh the negatives.


Last Reviewed:
January 31, 2018
Last Updated:
April 05, 2018
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