Nafcillin — uses, dosing, side effects & the brands that sell it · pharmaranks
Nafcillin: uses, dosing, side effects & brands
Nafcillin is a penicillin-class antibacterial sold in the U.S. under 4 brand and generic names, for cellulitis, bacterial endocarditis and osteomyelitis. Below: what the FDA label says, every product that contains it, what the pills look like, and its recall record.
By the pharmaranks editorial team·Reviewed against the FDA (openFDA label, NDC Directory & Enforcement) sources·How we research
Key facts
Drug class
Penicillin-Class Antibacterial
Treats
Cellulitis, Bacterial Endocarditis and Osteomyelitis
Available as
Injectable
Sold as
4 products — Nafcillin Sodium, Nallpen in Plastic Container and Unipen, and others
Prescription?
Prescription only
Generic available?
Yes
How nafcillin is dosed
From the FDA label for Nallpen in Plastic Container (application NDA050655). Other nafcillin products — different forms, different strengths — are dosed differently. Follow the label for the one you were prescribed.
Nafcillin Injection, USP supplied as a premixed frozen solution is to be administered as an intravenous infusion. The usual I.V. dosage for adults is 500 mg every 4 hours. For severe infections, 1 g every 4 hours is recommended. Administer slowly over at least 30 to 60 minutes to minimize the risk of vein irritation and extravasation. Bacteriologic studies to determine the causative organisms and their susceptibility to nafcillin should always be performed. Duration of therapy varies with the type and severity of infection as well as the overall condition of the patient; therefore, it should be determined by the clinical and bacteriological response of the patient. In severe staphylococcal infections, therapy with nafcillin should be continued for at least 14 days. The treatment of endocarditis and osteomyelitis may require a longer duration of therapy. No dosage alterations are necessary for patients with renal dysfunction, including those on hemodialysis. Hemodialysis does not accelerate nafcillin clearance from the blood. With intravenous administration, particularly in elderly patients, care should be taken because of the possibility of thrombophlebitis. Parenteral drug products should be inspected visually for particulate matter and discoloration prior to administration whenever solution and container permit. Do not add supplementary medication to Nafcillin Injection,…
Nafcillin side effects
Body as a Whole The reported incidence of allergic reactions to penicillin ranges from 0.7 to 10 percent (see WARNINGS ). Sensitization is usually the result of treatment, but some individuals have had immediate reactions to penicillin when first treated. In such cases, it is thought that the patients may have had prior exposure to the drug via trace amounts present in milk or vaccines. Two types of allergic reactions to penicillins are noted clinically, immediate and delayed. Immediate reactions usually occur within 20 minutes of administration and range in severity from urticaria and pruritus to angioedema, laryngospasm, bronchospasm, hypotension, vascular collapse, and death. Such immediate anaphylactic reactions are very rare (see WARNINGS ) and usually occur after parenteral therapy but have occurred in patients receiving oral therapy. Another type of immediate reaction, an accelerated reaction, may occur between 20 minutes and 48 hours after administration and may include urticaria, pruritus, and fever. Although laryngeal edema, laryngospasm, and hypotension occasionally occur, fatality is uncommon. Delayed allergic reactions to penicillin therapy usually occur after 48 hours and sometimes as late as 2 to 4 weeks after initiation of therapy. Manifestations of this type of reaction include serum sickness-like symptoms ( i.e., fever, malaise, urticaria, myalgia,…
Every nafcillin product we track (4)
Same active ingredient — different manufacturer, form, price and FDA recall record. That last one is what our independent score measures.
Nafcillin Injection, USP is a sterile injectable product containing nafcillin which is added as Nafcillin Sodium, USP, a semisynthetic penicillin derived from the penicillin nucleus, 6-aminopenicillanic acid. The chemical name of nafcillin sodium is Monosodium (2 S ,5 R ,6 R )-6-(2-ethoxy-1-naphthamido)-3,3-dimethyl-7-oxo-4-thia-1- azabicyclo[3.2.0]heptane-2-carboxylate monohydrate. It is resistant to inactivation by the enzyme penicillinase (beta-lactamase). The molecular formula of Nafcillin Sodium, USP is C 21 H 21 N 2 NaO 5 S·H 2 O. The molecular weight is 454.48. The structural formula of nafcillin sodium is as follows: Nafcillin Injection, USP is a frozen, iso-osmotic, sterile, nonpyrogenic premixed 100 mL solution containing 2 g of nafcillin, added as Nafcillin Sodium, USP. Dextrose, USP has been added to the above dosages to adjust osmolality (approximately 3.6 g as dextrose hydrous to the 2 g dosage. Sodium Citrate Hydrous, USP has been added as a buffer (approximately 180 mg to the 2 g dosage. The pH has been adjusted with hydrochloric acid and may have been adjusted with sodium hydroxide. The pH is 6.5 (6.0 to 8.5). The solution is intended for intravenous use after thawing to room temperature. This Galaxy container is fabricated from a specially designed multilayer plastic. Solutions are in contact with the polyethylene layer of this container and can leach out…
What kind of drug is nafcillin?
The FDA classifies nafcillin as a penicillin-class antibacterial. If you are checking whether it is safe to combine with something else, the class is what matters — two drugs from the same class usually should not be stacked.
Can you take nafcillin with other medicines?
It depends on the medicine. We check it against the FDA labels rather than guessing: our interaction checker searches each drug's own label for the other and quotes what it says, naming the section it came from. Run nafcillin against whatever else you take — and remember that a label not naming a drug is not the same as that combination being safe.
What brand names is nafcillin sold under?
We track 4 nafcillin-containing products in the U.S.: Nafcillin Sodium, Nallpen in Plastic Container, Unipen and Unipen in Plastic Container. They are the same active ingredient; they differ in form, manufacturer, price and FDA recall record.
Sources: FDA openFDA drug label, National Drug Code Directory, and Enforcement (recall) database. This page reproduces public FDA data and is not medical advice. Dosing is set by your prescriber.
Who shouldn’t take nafcillin
CONTRAINDICATION A history of a hypersensitivity (anaphylactic) reaction to any penicillin is a contraindication. Solutions containing dextrose may be contraindicated in patients with known allergy to corn or corn products.
Nafcillin drug interactions
Tetracycline, a bacteriostatic antibiotic, may antagonize the bactericidal effect of penicillin, and concurrent use of these drugs should be avoided. Nafcillin in high dosage regimens, i.e., 2 grams every 4 hours, has been reported to decrease the effects of warfarin. When nafcillin and warfarin are used concomitantly, the prothrombin time should be closely monitored and the dose of warfarin adjusted as necessary. This effect may persist for up to 30 days after nafcillin has been discontinued. Nafcillin when administered concomitantly with cyclosporine has been reported to result in subtherapeutic cyclosporine levels. The nafcillin-cyclosporine interaction was documented in a patient during two separate courses of therapy. When cyclosporine and nafcillin are used concomitantly in organ transplant patients, the cyclosporine levels should be monitored.
Across the brands we track, nafcillin is currently marketed as injectable, per the FDA's National Drug Code Directory. Each form is dosed differently — follow the label for the exact product you were prescribed.
Is there a generic nafcillin?
Yes. Our catalog lists 1 generic nafcillin product alongside the brand versions. A generic has the same active ingredient and must meet the FDA's bioequivalence standard; it usually costs less. Ask your pharmacist which one your plan covers.