Uses of Nafcillin:

• It is used to treat bacterial infections.

What do I need to tell my doctor BEFORE I take Nafcillin?

• If you have an allergy to nafcillin, any penicillin, or any other part of nafcillin.
• If you are allergic to nafcillin; any part of nafcillin; or any other drugs, foods, or substances. Tell your doctor about the allergy and what signs you had.
• If you are taking tetracycline.

This is not a list of all drugs or health problems that interact with nafcillin.

Tell your doctor and pharmacist about all of your drugs (prescription or OTC, natural products, vitamins) and health problems. You must check to make sure that it is safe for you to take nafcillin with all of your drugs and health problems. Do not start, stop, or change the dose of any drug without checking with your doctor.

What are some things I need to know or do while I take Nafcillin?

• Tell all of your health care providers that you take nafcillin. This includes your doctors, nurses, pharmacists, and dentists.
• Very bad and sometimes deadly allergic side effects have rarely happened. Talk with your doctor.
• If you have asthma, talk with your doctor. You may be more sensitive to nafcillin.
• Have your blood work checked if you are on nafcillin for a long time. Talk with your doctor.
• This medicine may affect certain lab tests. Tell all of your health care providers and lab workers that you take nafcillin.
• Do not use longer than you have been told. A second infection may happen.
• If you are on a low-sodium or sodium-free diet, talk with your doctor. Some of these products have sodium.
• Kidney problems have happened with nafcillin. Sometimes, people have needed dialysis. Kidney problems may be long-lasting. If you have questions, talk with the doctor.
• Use with care in children. Talk with the doctor.
• Tell your doctor if you are pregnant or plan on getting pregnant. You will need to talk about the benefits and risks of using nafcillin while you are pregnant.
• Tell your doctor if you are breast-feeding. You will need to talk about any risks to your baby.

How is this medicine (Nafcillin) best taken?

Use nafcillin as ordered by your doctor. Read all information given to you. Follow all instructions closely.

• It is given as a shot into a muscle or as an infusion into a vein over a period of time.

What do I do if I miss a dose?

• Call your doctor to find out what to do.

What are some side effects that I need to call my doctor about right away?

WARNING/CAUTION: Even though it may be rare, some people may have very bad and sometimes deadly side effects when taking a drug. Tell your doctor or get medical help right away if you have any of the following signs or symptoms that may be related to a very bad side effect:

• Signs of an allergic reaction, like rash; hives; itching; red, swollen, blistered, or peeling skin with or without fever; wheezing; tightness in the chest or throat; trouble breathing, swallowing, or talking; unusual hoarseness; or swelling of the mouth, face, lips, tongue, or throat.
• Signs of kidney problems like unable to pass urine, change in how much urine is passed, blood in the urine, or a big weight gain.
• Signs of liver problems like dark urine, feeling tired, not hungry, upset stomach or stomach pain, light-colored stools, throwing up, or yellow skin or eyes.
• Very bad dizziness or passing out.
• Twitching.
• Seizures.
• A burning, numbness, or tingling feeling that is not normal.
• Irritation has happened where nafcillin was given. Rarely, tissue damage has happened. Tell your nurse if you have any burning, color changes, pain, skin breakdown, or swelling where nafcillin was given.
• Diarrhea is common with antibiotics. Rarely, a severe form called C diff–associated diarrhea (CDAD) may happen. Sometimes, this has led to a deadly bowel problem (colitis). CDAD may happen during or a few months after taking antibiotics. Call your doctor right away if you have stomach pain, cramps, or very loose, watery, or bloody stools. Check with your doctor before treating diarrhea.
• Sometimes, allergic reactions may be delayed (as late as 2 to 4 weeks after starting nafcillin). Call your doctor if you have a weak feeling, fever, muscle or joint pain, or stomach pain.
• Low blood cell counts have happened with nafcillin. If blood cell counts get very low, this can lead to bleeding problems, infections, or anemia. Call your doctor right away if you have signs of infection like fever, chills, or sore throat; any unexplained bruising or bleeding; or if you feel very tired or weak.

What are some other side effects of Nafcillin?

All drugs may cause side effects. However, many people have no side effects or only have minor side effects. Call your doctor or get medical help if any of these side effects or any other side effects bother you or do not go away:

• Upset stomach or throwing up.
• Diarrhea.

These are not all of the side effects that may occur. If you have questions about side effects, call your doctor. Call your doctor for medical advice about side effects.

You may report side effects to the FDA at 1-800-332-1088. You may also report side effects at https://www.fda.gov/medwatch.

If OVERDOSE is suspected:

If you think there has been an overdose, call your poison control center or get medical care right away. Be ready to tell or show what was taken, how much, and when it happened.

How do I store and/or throw out Nafcillin?

• If you need to store nafcillin at home, talk with your doctor, nurse, or pharmacist about how to store it.

Consumer Information Use and Disclaimer

• If your symptoms or health problems do not get better or if they become worse, call your doctor.
• Do not share your drugs with others and do not take anyone else's drugs.
• Keep all drugs in a safe place. Keep all drugs out of the reach of children and pets.
• Throw away unused or expired drugs. Do not flush down a toilet or pour down a drain unless you are told to do so. Check with your pharmacist if you have questions about the best way to throw out drugs. There may be drug take-back programs in your area.
• Some drugs may have another patient information leaflet. Check with your pharmacist. If you have any questions about nafcillin, please talk with your doctor, nurse, pharmacist, or other health care provider.
• If you think there has been an overdose, call your poison control center or get medical care right away. Be ready to tell or show what was taken, how much, and when it happened.