• you are allergic to any ingredient in Zyvox
• you are taking an amphetamine (eg, dextroamphetamine), certain anorexiants (eg, phentermine), buspirone, a catechol-O-methyltransferase (COMT) inhibitor (eg, entacapone), levodopa, meperidine, a sympathomimetic (eg, albuterol, dopamine, epinephrine, pseudoephedrine), tetrabenazine, or triptans (eg, sumatriptan)
• you are taking or have taken certain anorexiants (eg, sibutramine), apraclonidine, bupropion, cyclobenzaprine, a monoamine oxidase inhibitor (MAOI) (eg, phenelzine), a norepinephrine reuptake inhibitor (eg, atomoxetine), a serotonin-norepinephrine reuptake inhibitor (SNRI) (eg, duloxetine), a serotonin reuptake inhibitor (eg, paroxetine), a tetracyclic antidepressant (eg, maprotiline), or a tricyclic antidepressant (eg, amitriptyline) within the past 14 days.

Contact your doctor or health care provider right away if any of these apply to you.

Some medical conditions may interact with Zyvox. Tell your doctor or pharmacist if you have any medical conditions, especially if any of the following apply to you:

• if you are pregnant, planning to become pregnant, or are breast-feeding
• if you are taking any prescription or nonprescription medicine, herbal preparation, or dietary supplement
• if you have allergies to medicines, foods, or other substances
• if you have a history of high blood pressure, kidney problems, eye or vision problems, bone marrow problems, low blood cell or platelet levels, an adrenal gland tumor (pheochromocytoma), carcinoid syndrome, severe liver problems, seizures, or an overactive thyroid
• if you have a prolonged infection that has been previously treated with another antibiotic medicine
• if you are taking any medicine for depression.

Some medicines may interact with Zyvox. Tell your health care provider if you are taking any other medicines, especially any of the following:

• Amphetamines (eg, dextroamphetamine), certain anorexiants (eg, phentermine, sibutramine), apraclonidine, ginseng, meperidine, sympathomimetics (eg, albuterol, dopamine, epinephrine, pseudoephedrine), or tryptophan because the risk of serious side effects, including severe headache, fever, or high blood pressure, may be increased
• Bupropion, buspirone, catechol-O-methyltransferase (COMT) inhibitors (eg, entacapone), levodopa, MAOIs (eg, phenelzine), norepinephrine reuptake inhibitors (eg, atomoxetine), propoxyphene, SNRIs (eg, duloxetine), tetrabenazine, tetracyclic antidepressants (eg, maprotiline), tricyclic antidepressants (eg, amitriptyline), or triptans (eg, sumatriptan) because the risk of serious side effects, including severe fever, mental or mood changes, or muscle problems, may be increased
• Carbamazepine, barbiturates (eg, phenobarbital), hydantoins (eg, phenytoin), or rifamycins (eg, rifampin) because they may decrease Zyvox's effectiveness.

This may not be a complete list of all interactions that may occur. Ask your health care provider if Zyvox may interact with other medicines that you take. Check with your health care provider before you start, stop, or change the dose of any medicine.

Important safety information:

• Zyvox may cause dizziness. This effect may be worse if you take it with alcohol or certain medicines. Use Zyvox with caution. Do not drive or perform other possible unsafe tasks until you know how you react to it.
• Be sure to use Zyvox for the full course of treatment. If you do not, the medicine may not clear up your infection completely. The bacteria could also become less sensitive to this or other medicines. This could make the infection harder to treat in the future.
• Long-term or repeated use of Zyvox may cause a second infection. Tell your doctor if signs of a second infection occur. Your medicine may need to be changed to treat this.
• Mild diarrhea is common with antibiotic use. However, a more serious form of diarrhea (pseudomembranous colitis) may rarely occur. This may develop while you use the antibiotic or within several months after you stop using it. Contact your doctor right away if stomach pain or cramps, severe diarrhea, or bloody stools occur. Do not treat diarrhea without first checking with your doctor.
• Eating foods high in tyramine (eg, aged cheeses, red wines, beer, certain meats and sausages, liver, sour cream, soy sauce, raisins, bananas, avocados) while you use an MAOI may cause severe high blood pressure. This could occur for up to 2 weeks after you stop taking an MAOI. Do not eat foods high in tyramine while you take Zyvox. Ask your health care provider for a complete list of foods you should avoid. Seek medical attention at once if symptoms of severe high blood pressure occur. These may include severe headache, fast or irregular heartbeat, sore or stiff neck, nausea, vomiting, sweating, enlarged pupils, or sensitivity to light.
• Zyvox may reduce the number of clot-forming cells (platelets) in your blood. Avoid activities that may cause bruising or injury. Tell your doctor if you have unusual bruising or bleeding. Tell your doctor if you have dark, tarry, or bloody stools.
• Zyvox only works against bacteria; it does not treat viral infections (eg, the common cold).
• Lactic acidosis has occurred with the use of Zyvox. Contact your doctor if you have severe, persistent nausea, vomiting, stomach pain, or unusual tiredness or weakness.
• Serious eye problems (eg, peripheral and optic neuropathy) have occurred with the use of Zyvox. Contact your doctor if you experience vision changes (eg, decreased or blurred vision, changes in color vision, loss of vision).
• Lab tests, including complete blood cell counts and eye exams, may be performed while you use Zyvox. These tests may be used to monitor your condition or check for side effects. Be sure to keep all doctor and lab appointments.
• Zyvox should be used with extreme caution in children; safety and effectiveness in children have not been confirmed.
• Pregnancy and breast-feeding: If you become pregnant, contact your doctor. You will need to discuss the benefits and risks of using Zyvox while you are pregnant. It is not known if Zyvox is found in breast milk. If you are or will be breast-feeding while you use Zyvox, check with your doctor. Discuss any possible risks to your baby.

Check with your doctor if any of these most common side effects persist or become bothersome:

Bad taste in mouth; constipation; diarrhea; dizziness; headache; nausea; trouble sleeping; vomiting.

Seek medical attention right away if any of these severe side effects occur:

Severe allergic reactions (rash; hives; itching; difficulty breathing; tightness in the chest; swelling of the mouth, face, lips, or tongue; unusual hoarseness); agitation; bloody stools; bloody vomit; chills, fever, or sore throat; confusion; exaggerated reflexes; excitation; fast heartbeat; loss of coordination; mental or mood changes; muscle spasms; prolonged or repeated nausea or vomiting; red, swollen, peeling, or blistered skin; seizures; severe or continuing diarrhea; stomach pain/cramps; sweating; swelling of the hands or feet; tingling or numbness of the hands or feet; unusual bleeding or bruising; unusual tiredness or weakness; vaginal irritation or unusual discharge; vision changes (including decreased or blurred vision, changes in color vision, loss of vision); white patches in the mouth.

This is not a complete list of all side effects that may occur. If you have questions about side effects, contact your health care provider.