In the U.S.—

• Antibacterial, systemic

Linezolid (li-NE-zoh-lid ) belongs to the family of medicines called antibiotics. Antibiotics are medicines used in the treatment of infections caused by bacteria. They work by killing bacteria or preventing their growth. Linezolid will not work for colds, flu, or other virus infections.

Linezolid is used to treat infections of the blood, lungs, and skin. It may also be used for other conditions as determined by your doctor. It is given by injection or orally. It is used mainly for serious infection for which other medicines may not work.

This medicine is available only with your doctor's prescription, in the following dosage forms:

Oral
• Oral Suspension (U.S.)
• Tablets (U.S.)

Parenteral
• Injection (U.S.)

In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For linezolid, the following should be considered:

Allergies—Tell your doctor if you have ever had any unusual or allergic reaction to linezolid. Also tell your health care professional if you are allergic to any other substances, such as foods, preservatives, or dyes.

Pregnancy—Linezolid has not been studied in pregnant women. Before taking this medicine, make sure your doctor knows if you are pregnant of if you may become pregnant.

Breast-feeding— It is not known whether linezolid passes into breast milk. Although most medicines pass into breast milk in small amounts, many of them may be used safely while breast-feeding. Mothers who are taking this medicine and who wish to breast-feed should discuss this with their doctor.

Children—Studies on this medicine have been done only in adult patients, and there is no specific information comparing use of linezolid in children with use in other age groups.

Older adults—This medicine has been tested and has not been shown to cause different side effects or problems in older people than it does in younger adults.

Other medicines— Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking linezolid, it is especially important that your health care professional know if you are taking any of the following:

• Citalopram (e.g., Celexa) or
• Clomipramine (e.g., Anafranil) or
• Fluvoxamine (e.g., Luvox) or
• Moclobemide (e.g., Manerix) or
• Monoamine oxidase (MAO) inhibitors (furazolidone [e.g., Furoxone], phenylzine [e.g., Nardil], procarbazine [e.g., Matulane], selegiline [e.g., Eldepryl], tranylcypromine [e.g., Parnate]) or
• Nefazodone (e.g., Serzone) or
• Paroxetine (e.g., Paxil) or
• Sertraline (e.g., Zoloft) or
• Sibutramine (e.g., Meridia) or
• Tryptophan (e.g., Alti-Tryptophan) or
• Venlafaxine (e.g., Effexor)—Using these medicines with linezolid may increase the chance of developing a rare, but very serious, unwanted effect known as the serotonin syndrome

• Pseudoephedrine (e.g., Rondex®, Sudafed®)—Using pseudoephedrine with linezolid may cause an increase in your blood pressure

• Phenylketonuria—The oral suspension contains phenylalanine, which may cause side effects; however, the other dosage forms do not contain phenylalanine

• The liquid form of linezolid should be gently mixed by turning the bottle upside down 3 to 5 times before each dose. Do not shake this product.
• Do not use after the expiration date on the label. The medicine may not work properly after that date. If you have any questions about this, check with your pharmacist.

To help clear up your infection completely, keep taking this medicine for the full time of treatment, even if you begin to feel better after a few days. Also, it works best when there is a constant amount in the blood. To help keep the amount constant, linezolid must be given on a regular schedule.

Dosing—

The dose of linezolid will be different for different patients. Follow your doctor's orders or the directions on the label. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are taking linezolid .

• For oral dosage forms:
  • Adults—400 or 600 mg every 12 hours.
  • Children—Dose must be determined by your doctor.
• For parenteral dosage form (injection):
  • Adults—600 mg every 12 hours.
  • Children—Dose must be determined by your doctor.

Missed dose—

If you miss a dose of this medicine, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not double doses.

Storage—

To store this medicine:

• Store at room temperature.
• Do not store in the bathroom, near the kitchen sink, or in other damp places. Heat or moisture may cause the medicine to break down.
• Do not keep outdated medicine or medicine no longer needed. Ask your health care professional how you should dispose of any medicine you do not use. Be sure that any discarded medicine is out of the reach of children.

If your symptoms do not improve within a few days or if they become worse, check with your doctor.

Linezolid can lower the number of white blood cells in your blood temporarily, increasing the chance of getting an infection. It can also lower the number of platelets, which are necessary for proper blood clotting. If this occurs, there are certain precautions your doctor may ask you to take, especially when your blood count is low, to reduce the risk of infection or bleeding:

• If you can, avoid people with infections. Check with your doctor immediately if you think you are getting an infection or if you get a fever or chills.
• Check with your doctor immediately if you notice any unusual bleeding or bruising.
• Do not touch your eyes or the inside of your nose unless you have just washed your hands and have not touched anything else in the meantime.
• Be careful not to cut yourself when you are using sharp objects such as a safety razor or fingernail or toenail cutters.
• Avoid contact sports or other situations where bruising or injury could occur.

When taken with certain foods or drinks, linezolid can cause an increase in blood pressure. To avoid this, do not eat large amounts of foods or drink beverages that have a high tyramine content (most common in foods that are aged, fermented, pickled, or smoked to increase their flavor, such as aged cheeses; air-dried, fermented, or smoked fish, meat, or poultry; sauerkraut; soy sauce; red wine; or tap beer. If a list of these foods and beverages is not given to you, ask your health care professional to provide one.

Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

• Diarrhea 

• Less common or rare
  • Abdominal or stomach cramps or pain (severe);  black, tarry stools;  blood in urine or stools;  chills;  cough ;  diarrhea (severe and watery, may also be bloody) ;  discharge from the vagina;  fever;  headache;  hoarseness ;  itching of the vagina;  lower back or side pain;  painful or difficult urination ;  pinpoint red spots on skin;  shortness of breath;  sore mouth or tongue;  unusual bleeding or bruising;  unusual tiredness or weakness;  white patches in mouth, tongue, or throat 
  
  

Other side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. However, check with your doctor if any of the following side effects continue or are bothersome.

• More common
  • Nausea  
  
  

• Less common or rare
  • Bad taste in the mouth;  change in sense of taste;  change in color of tongue;  dizziness;  loss of taste;  vomiting 
  
  

Other side effects not listed above may also occur in some patients. If you notice any other effects, check with your doctor.