Generic Name: Nafcillin Brand Name(s): Generics only. No brands available. Avability: Rx Pregnancy Category: B

Uses

What is Nafcillin used for?

Nafcillin is used to treat a wide variety of bacterial infections. This medication is known as a penicillin-type antibiotic. It works by stopping the growth of bacteria.

How should I take Nafcillin?

Nafcillin is injected into a muscle, or into a vein through an IV. You may be shown how to use injections at home. Do not give yourself this medicine if you do not fully understand how to give the injection and properly dispose of used needles, IV tubing, and other items used to inject the medicine.

This medicine must be given slowly, and the infusion can take 30 to 60 minutes to complete.

Nafcillin powder must be mixed with a liquid (diluent) before using it. If you are using the injections at home, be sure you understand how to properly mix and store the medicine.

Your medicine may also be supplied as a premixed solution that has been frozen in a plastic container.

After mixing nafcillin powder with a diluent, store in the refrigerator and use within 7 days.

Mixed medicine must be used within 24 hours if you keep it at room temperature.

Do not use nafcillin if it has changed colors or has particles in it. Call your pharmacist for new medication.

Tell your caregivers if you feel any burning, pain, or swelling around the IV needle when the medicine is injected.

How do I store Nafcillin?

Store unmixed nafcillin powder at room temperature away from moisture and heat.

Store frozen nafcillin in a deep freezer, at -4 degrees Fahrenheit (-20 degrees Celsius).

Take the medicine out of the freezer and allow it to reach room temperature before injecting your dose. Do not use heat to thaw frozen nafcillin.

There may be different brands of Nafcillin that may have different storage needs. It is important to always check the product package for instructions on storage, or ask your pharmacist. For safety, you should keep all medicines away from children and pets.

You should not flush Nafcillin down the toilet or pour them into a drain unless instructed to do so. It is important to properly discard this product when it is expired or no longer needed. Consult your pharmacist for more details about how to safely discard your product.

Precautions & warnings

What should I know before using Nafcillin?

Before using this medication, tell your doctor or pharmacist if you are allergic to it; or to penicillin or cephalosporin antibiotics; or if you have any other allergies. This product may contain inactive ingredients (such as corn for products containing dextrose), 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: asthma, kidney disease, liver disease.

This medication contains sodium. This could affect you if you are on a salt-restricted diet or if you have a condition which could be worsened with an increase in salt intake (e.g., congestive heart failure). Consult your doctor or pharmacist for more information.

Nafcillin may cause live bacterial vaccines (such as typhoid vaccine) to not work as well. Do not have any immunizations/vaccinations while using this medication unless your doctor tells you to.

Liver and kidney functions decline as you grow older. This medication is removed by the liver. Therefore, elderly people may be at greater risk for side effects while using this drug.

Liver and kidney functions are not fully developed in newborns and infants. This medication is removed by the liver. Therefore, newborns and infants may be a greater risk for side effects while using this drug.

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

This drug passes into breast milk. Consult your doctor before breast-feeding.

Is it safe during pregnancy or breast-feeding?

There are no adequate studies in women for determining risk when using this Nafcillin during pregnancy or while breastfeeding. Please always consult with your doctor to weigh the potential benefits and risks before taking Nafcillin. Nafcillin is pregnancy risk category B according to the US Food and Drug Administration (FDA).

FDA pregnancy risk category reference below:

  • A=No risk,
  • B=No risk in some studies,
  • C=There may be some risk,
  • D=Positive evidence of risk,
  • X=Contraindicated,
  • N=Unknown

Side effects

What side effects can occur from Nafcillin?

If this medication is injected into a muscle, pain at the injection site may occur. If this effect persists or worsens, notify your doctor or pharmacist promptly.

Tell your doctor right away if you have any serious side effects, including: pain/swelling/skin peeling at injection site (if this drug is injected into a vein), joint/muscle pain, signs of kidney problems (such as change in the amount of urine, dark/cloudy urine), extreme tiredness, easy bruising/bleeding, new signs of infection (e.g., fever, persistent sore throat), seizures, uncontrolled movements, confusion, irregular heartbeat, muscle cramps, weakness.

This medication may rarely cause a severe intestinal condition (Clostridium difficile-associated diarrhea) due to a type of resistant bacteria. This condition may occur during treatment or weeks to months after treatment has stopped. Do not use anti-diarrhea products or narcotic pain medications if you have any of the following symptoms because these products may make them worse. Tell your doctor right away if you develop: persistent diarrhea, abdominal or stomach pain/cramping, blood/mucus in your stool.

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.

Not everyone experiences these side effects. There may be some side effects not listed above. If you have any concerns about a side-effect, please consult your doctor or pharmacist.

Interactions

What drugs may interact with Nafcillin?

Some products that may interact with this drug include: “blood thinners” (e.g., warfarin), methotrexate, tetracyclines.

This medication can speed up the removal of other medications from your body, which may affect how they work. Examples of affected drugs include certain products used to treat chronic hepatitis C (asunaprevir, ombitasvir/paritaprevir/ritonavir), among others.

Although most antibiotics are unlikely to affect hormonal birth control such as pills, patch, or ring, a few antibiotics (such as rifampin, rifabutin) can decrease their effectiveness. This could result in pregnancy. If you use hormonal birth control, ask your doctor or pharmacist for more details.

This medication may interfere with certain laboratory tests (including certain urine protein tests), possibly causing false test results. Make sure laboratory personnel and all your doctors know you use this drug.

Nafcillin may interact with other drugs that you are currently taking, which can change how your drug works or increase your risk for serious side effects. To avoid any potential drug interactions, you should keep a list of all the drugs you are using (including prescription drugs, nonprescription drugs and herbal products) and share it with your doctor and pharmacist. For your safety, do not start, stop, or change the dosage of any drugs without your doctor’s approval.

Does food or alcohol interact with Nafcillin?

Nafcillin may interact with food or alcohol by altering the way the drug works or increase the risk for serious side effects. Please discuss with your doctor or pharmacist any potential food or alcohol interactions before using this drug.

What health conditions may interact with Nafcillin?

Nafcillin may interact with your health condition. This interaction may worsen your health condition or alter the way the drug works. It is important to always let your doctor and pharmacist know all the health conditions you currently have.

Dosage

The information provided is not a substitute for any medical advice. You should ALWAYS consult with your doctor or pharmacist before using this Nafcillin.

What is the dose of Nafcillin for an adult?

Usual Adult Dose for Bacteremia

2 g IV every 4 hours for 14 days depending on the nature and severity of the infection

Usual Adult Dose for Endocarditis

Native valve endocarditis due to staphylococci: Nafcillin 2 g IV every 4 hours or 3 g IV every 6 hours (total 12 g/day) with or without gentamicin 3 mg/kg/day in 2 or 3 divided doses

Duration: Nafcillin, 6 weeks; gentamicin 3 to 5 days

Prosthetic valve endocarditis due to staphylococci: Nafcillin 2 g IV every 4 hours or 3 g IV every 6 hours (total 12 g/day) plus rifampin 300 mg orally every 8 hours, with or without gentamicin 3 mg/kg/day in 2 or 3 divided doses

Duration: Nafcillin and rifampin, 6 weeks or more; gentamicin 2 weeks

Refer to current published guidelines for detailed recommendations.

Usual Adult Dose for Joint Infection

2 g IV every 4 hours for 3 to 4 weeks, depending on the nature and severity of the infection

Longer therapy, for 6 weeks or more, may be required for prosthetic joint infections.

Usual Adult Dose for Meningitis

2 g IV every 4 hours for 14 days

Usual Adult Dose for Osteomyelitis

2 g IV every 4 hours for 4 to 6 weeks, depending on the nature and severity of the infection

Chronic osteomyelitis may require additional oral antibiotic therapy, possibly for up to 6 months.

Usual Adult Dose for Pneumonia

2 g IV every 4 hours

Therapy should continue for up to 21 days depending on the nature and severity of the infection.

Usual Adult Dose for Skin or Soft Tissue Infection

1 to 2 g IV every 4 to 6 hours for 7 days, or for 3 days after acute inflammation resolves, depending on the nature and severity of the infection

More severe infections, such as diabetic soft tissue infections, may require 14 to 21 days of therapy.

Renal Dose Adjustments

For patients with both severe renal and hepatic impairment, the dose used should be the lower range of the usual dose or reduced by 33% to 50%, or the frequency may be reduced.

Liver Dose Adjustments

For patients with both severe renal and hepatic impairment, the dose used should be the lower range of the usual dose or reduced by 33% to 50%, or the frequency may be reduced.

Precautions

Serious and occasionally fatal hypersensitivity reactions have been reported with antibiotics. The drug should be discontinued immediately at the first appearance of a skin rash or other signs of hypersensitivity. Severe, acute hypersensitivity reactions may require treatment with epinephrine and other resuscitative measures including oxygen, intravenous fluids, antihistamines, corticosteroids, cardiovascular support and airway management as clinically indicated.

Clostridium difficile associated diarrhea (CDAD) has been reported with almost all antibiotics and may potentially be life-threatening. Therefore, it is important to consider this diagnosis in patients who present with diarrhea following nafcillin therapy. Mild cases generally improve with discontinuation of the drug, while severe cases may require supportive therapy and treatment with an antimicrobial agent effective against C difficile. Hypertoxin producing strains of C difficile cause increased morbidity and mortality; these infections can be resistant to antimicrobial treatment and may necessitate colectomy.

Solutions containing dextrose may be contraindicated with patients with known allergies to corn or corn products.

Caution is recommended in patients with asthma or history of allergies.

The IV route of administration should be used for relatively short term therapy (24 to 48 hours) because of the occasional occurrence of thrombophlebitis, particularly in elderly patients. Extravasation may result in tissue necrosis, ulceration, sloughing, and gangrene, and should be avoided. If the patient experiences pain during administration, the infusion should be stopped and the patient evaluated for thrombophlebitis and extravasation.

Nafcillin injection contains 3.33 mEq sodium per gram. This may be significant for elderly patients or in conditions such as congestive heart failure. Monitoring of cardiac, vascular, and electrolyte status is recommended.

Periodic monitoring of renal, hepatic, and hematologic function is recommended during prolonged therapy.

Nafcillin may cause false-positive results for urine protein by the sulfosalicylic acid test.

There are no approved dosing regimens for the IV route of administration in neonates and children.

Because of immature hepatic and renal function in newborns, nafcillin excretion may be decreased in neonates. Use with extreme caution in neonates less than 2 weeks old and consider monitoring serum levels.

Dialysis

Nafcillin is not dialyzable.

What is the dose of Nafcillin for a child?

Usual Pediatric Dose for Pharyngitis

The safety and efficacy of nafcillin when administered IV in neonates and children have not been established. However, the use of nafcillin IV may be appropriate in some situations.

0 to 4 weeks, birthweight 1199 g or less: 25 mg/kg IV or IM every 12 hours

7 days or less:

birthweight 1200 to 2000 g: 25 mg/kg IV or IM every 12 hours

birthweight 2001 g or more: 25 mg/kg IV or IM every 8 hours

8 days up to 1 month:

birthweight 1200 to 2000 g: 25 mg/kg IV or IM every 8 hours

birthweight 2001 g or more: 25 to 35 mg/kg IV or IM every 6 hours

1 month to 18 years:

Mild to moderate infections: 12.5 to 25 mg/kg IV or IM every 6 hours

Severe infections: 100 to 200 mg/kg/day IV in equally divided doses every 4 to 6 hours

Maximum dose: 12 g/day

Usual Pediatric Dose for Pneumonia

The safety and efficacy of nafcillin when administered IV in neonates and children have not been established. However, the use of nafcillin IV may be appropriate in some situations.

0 to 4 weeks, birthweight 1199 g or less: 25 mg/kg IV or IM every 12 hours

7 days or less:

birthweight 1200 to 2000 g: 25 mg/kg IV or IM every 12 hours

birthweight 2001 g or more: 25 mg/kg IV or IM every 8 hours

8 days up to 1 month:

birthweight 1200 to 2000 g: 25 mg/kg IV or IM every 8 hours

birthweight 2001 g or more: 25 to 35 mg/kg IV or IM every 6 hours

1 month to 18 years:

Mild to moderate infections: 12.5 to 25 mg/kg IV or IM every 6 hours

Severe infections: 100 to 200 mg/kg/day IV in equally divided doses every 4 to 6 hours

Maximum dose: 12 g/day

Usual Pediatric Dose for Bacterial Infection

The safety and efficacy of nafcillin when administered IV in neonates and children have not been established. However, the use of nafcillin IV may be appropriate in some situations.

0 to 4 weeks, birthweight 1199 g or less: 25 mg/kg IV or IM every 12 hours

7 days or less:

birthweight 1200 to 2000 g: 25 mg/kg IV or IM every 12 hours

birthweight 2001 g or more: 25 mg/kg IV or IM every 8 hours

8 days up to 1 month:

birthweight 1200 to 2000 g: 25 mg/kg IV or IM every 8 hours

birthweight 2001 g or more: 25 to 35 mg/kg IV or IM every 6 hours

1 month to 18 years:

Mild to moderate infections: 12.5 to 25 mg/kg IV or IM every 6 hours

Severe infections: 100 to 200 mg/kg/day IV in equally divided doses every 4 to 6 hours

Maximum dose: 12 g/day

Usual Pediatric Dose for Skin and Structure Infection

The safety and efficacy of nafcillin when administered IV in neonates and children have not been established. However, the use of nafcillin IV may be appropriate in some situations.

0 to 4 weeks, birthweight 1199 g or less: 25 mg/kg IV or IM every 12 hours

7 days or less:

birthweight 1200 to 2000 g: 25 mg/kg IV or IM every 12 hours

birthweight 2001 g or more: 25 mg/kg IV or IM every 8 hours

8 days up to 1 month:

birthweight 1200 to 2000 g: 25 mg/kg IV or IM every 8 hours

birthweight 2001 g or more: 25 to 35 mg/kg IV or IM every 6 hours

1 month to 18 years:

Mild to moderate infections: 12.5 to 25 mg/kg IV or IM every 6 hours

Severe infections: 100 to 200 mg/kg/day IV in equally divided doses every 4 to 6 hours

Maximum dose: 12 g/day

Usual Pediatric Dose for Endocarditis

Native valve endocarditis due to staphylococci: 200 mg/kg/day IV in equally divided doses every 4 to 6 hours for 6 weeks

Prosthetic valve endocarditis due to staphylococci: 200 mg/kg/day IV in equally divided doses every 4 to 6 hours for 6 weeks or longer with rifampin and gentamicin for the first 2 weeks of therapy

Maximum dose: 12 g/day

Refer to current published guidelines for detailed recommendations.

How is Nafcillin available?

Nafcillin is available in the following dosage forms and strengths:

  • Oral capsule,
  • Injectable powder for injection,
  • Intravenous solution.

What should I do in case of an emergency or overdose?

In case of an emergency or an overdose, call your local emergency services or go to your nearest emergency room.

What should I do if I miss a dose?

If you miss a dose of Nafcillin, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and take your regular dose as scheduled. Do not take a double dose.

 

Hello Health Group does not provide medical advice, diagnosis or treatment.

Sources

Review Date: August 10, 2018 | Last Modified: August 10, 2018

Want to live your best life?
Get the Hello Doktor Daily newsletter for health tips, wellness updates and more.