Nafcillin 2 g/8mL Injection, Powder, Lyophilized, For Solution
🆔 Identity & classification
Where does this data come from?
🏷️ RxNorm drug class
This medicine belongs to the Penicillin-class Antibacterial class.
Where does this data come from?
🏭 Manufacturer & labeler
Where does this data come from?
🩺 Clinical
Nafcillin injection is used to treat infections caused by certain types of bacteria. Nafcillin injection is in a class of medications called penicillins. It works by killing bacteria. Antibiotics such as nafcillin injection will not work for colds, flu, or other viral infections. Taking antibiotics when they are not needed increases your risk of getting an infection later that resists antibiotic treatment.
Read the full MedlinePlus article ↗- Nafcillin is used specifically for infections caused by staphylococci — a type of bacteria — that have become resistant to regular penicillin. These 'penicillinase-producing' staph...
- What kind of infection is nafcillin used for?
- NAFCILLIN Injection is formulated to be given directly into a vein (IV) or into a muscle (IM). This route allows the medication to get into your bloodstream quickly and reach effec...
- Why is it given as an injection instead of a pill?
Patient education
Supplement & herbal interactions
Some supplements/herbs that may interact with Nafcillin Sodium — tap one for details:
Nafcillin Sodium may be associated with lower levels of 7 nutrients — worth a chat with your pharmacist, not a cause for alarm.
Where does this data come from?
Ask a licensed pharmacist directly — free, answered by our team.
🧪 Inactive Ingredients / Excipients
Inactive ingredients, also called excipients, are components of the drug product other than the active ingredient. They may include fillers, dyes, coatings, preservatives, flavors, or other formulation ingredients.
💡 Tap an ingredient (hover on desktop) to see what it is and why it’s used.
-
40 mg / 8 mL
UNII 1Q73Q2JULR
Sodium citrate is a salt derived from citric acid. It works as a buffer to maintain the medicine's pH level and may also help improve taste or act as a preservative in the formulation.
1 inactive ingredient listed in the exact product block matched to this NDC.
Where does this data come from?
ingredient classCode="IACT" elements from the exact product block matched by this NDC. Label-section narrative from DailyMed / the openFDA label index is shown separately when available.Inactive ingredient FAQ
Are inactive ingredients the same for every manufacturer?
Why might an inactive ingredient be missing?
Can inactive ingredients matter?
💲 Pricing
A drug doesn't have one price. Each row is a different public payment system, and none is what you'd pay at the counter — that depends on your insurance. The ⓘ on each row explains what it measures.
| Price system | Per mL | Per package |
|---|---|---|
| Retail pharmacies payNADAC · weekly | Not in the retail survey — common for institutional, discontinued, or low-volume packs. | |
| Medicaid paysCMS SDUD · 12 mo | No recent Medicaid claims on file for this NDC — rare and low-volume NDCs are suppressed in the public data. | |
| Medicare drug plans payPart D · Q2 2026 | $9.11 | $728.87 / 80 ml |
| Medicare Part B allowsASP · J2290 | $0.047 / J2290 unit | — |
Where does this data come from?
🧾 Billing & reimbursement
Where does this data come from?
🔁 Therapeutic equivalents
| Product | Labeler | Pack | NADAC/unit | TE | Status | Price vs. this |
|---|---|---|---|---|---|---|
| Nafcillin 2 g/100mL 00338-1019-48 | Baxter | 100 ml | — | — | FDA listed | — |
| Nafcillin 2 g/8mL 23155-0907-41 | Heritage | 10 vials | — | AP | FDA listed | — |
| Nafcillin 2 g 44567-0222-10 | WG | 10 vials | — | AP | FDA listed | — |
| Nafcillin 2 g/8mL 55150-0123-16 | Eugia | 10 vials | — | AP | FDA listed | — |
| Nafcillin 2 g/8mLthis 63323-0328-22 | Fresenius | 10 vials | — | AP | FDA listed | — |
| Nafcillin Sodium 2 g 72485-0406-10 | Armas | 10 vials | — | AP | FDA listed | — |
| Nafcillin 2 g/8mL 72603-0453-01 | NorthStar | 1 vial | — | AP | FDA listed | — |
| Nafcillin Sodium 2 g 83270-0310-10 | ONESOURCE | 10 vials | — | AP | FDA listed | — |
Where does this data come from?
⏳ Availability & generic status
This product is an FDA-approved generic. Other versions of the same drug are listed under Therapeutic equivalents, least expensive first.
Where does this data come from?
💊 Medicaid utilization by pack size
📊 Medicare Part D spend CMS · PART D · 2026 (Q1)
🔬 Reported adverse events (FAERS)
Top reported reactions
Age at onset
Reporter sex
Serious outcomes
Where does this data come from?
📦 Packaging — all sizes for this product
| Package NDC | Description | Marketing start | Status |
|---|---|---|---|
| 63323-0328-20 | 10 VIAL in 1 CARTON (63323-328-20) / 8 mL in 1 VIAL (63323-328-21) | 2011-06-30 | Active |
| 63323-0328-22 You're viewing this | 10 VIAL in 1 CARTON (63323-328-22) / 8 mL in 1 VIAL | 2011-06-30 | Active |
Pack size FAQ
What quantity is in NDC 63323-0328-22?
What NDC number is used to bill for this package of Nafcillin 2 g/8mL Injection, Powder, Lyophilized, For Solution?
🧭 About this NDC listing & data coverage
What data is (and isn’t) available for this NDC — tap to expand
| NDC identity (package / product / labeler codes) | ✓ Available |
| Labeler | ✓ Available |
| Product & package description | ✓ Available |
| Marketing category & status | ✓ Available |
| Active ingredient / dosage form / route | ✓ Available |
| FDA label (SPL via DailyMed) | ✓ Available |
| Package photos | ✓ Available |
| Inactive ingredients (structured) | ✓ Available |
| NADAC pharmacy acquisition price (CMS) | — Not published for this NDC CMS publishes NADAC only for NDCs reported in its retail-pharmacy survey. |
| Orange Book / therapeutic-equivalence data | ✓ Available |
| HCPCS J-code billing crosswalk | ✓ Available |
| Medicaid utilization (CMS SDUD) | — Not published for this NDC CMS reports utilization only for NDCs with Medicaid claims above its privacy threshold. |
Questions about this listing
Why is there no price listed?
Is the NDC printed on the package the same as the 11-digit billing NDC?
What do the three segments of this NDC mean?
Is this package still being marketed?
Does this product come in other package sizes?
Who lists this product with the FDA?
Do I need a prescription for this product?
Does this product have a billing J-code?
Where does this data come from?
📄 Full prescribing information FDA SPL
🎯 Indications and Usage ▾
INDICATIONS AND USAGE: Nafcillin is indicated in the treatment of infections caused by penicillinase-producing staphylococci which have demonstrated susceptibility to the drug. Culture and susceptibility tests should be performed initially to determine the causative organism and its susceptibility to the drug (see CLINICAL PHARMACOLOGY , Susceptibility Testing ). Nafcillin should not be used in infections caused by organisms susceptible to penicillin G.
If the susceptibility tests indicate that the infection is due to a methicillin-resistant Staphylococcus sp., therapy with Nafcillin for Injection should be discontinued and alternative therapy provided. To reduce the development of drug-resistant bacteria and maintain the effectiveness of Nafcillin for Injection and other antibacterial drugs, Nafcillin for Injection should be used only to treat or prevent infections that are proven or strongly suspected to be caused by susceptible bacteria. When culture and susceptibility information are available, they should be considered in selecting or modifying antibacterial therapy.
In the absence of such data, local epidemiology and susceptibility patterns may contribute to the empiric selection of therapy.
⏱️ Dosage and Administration ▾
DOSAGE AND ADMINISTRATION: Nafcillin for Injection is available for intramuscular and intravenous use. The usual IV dosage for adults is 500 mg every 4 hours. For severe infections, 1 gram every 4 hours is recommended.
Administer slowly over at least 30 to 60 minutes to minimize the risk of vein irritation and extravasation. Recommended Dosage for Nafcillin for Injection, USP Drug Adults Infants and Children <40 kg (88 lbs) Other Recommendations Nafcillin 500 mg IM every 4 to 6 hours. IV every 4 hours 25 mg/kg IM twice daily Neonates 10 mg/kg IM twice daily Nafcillin 1 gram IM or IV every 4 hours (severe infections) 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 for Injection, USP.
⛔ Contraindications ▾
CONTRAINDICATIONS: A history of a hypersensitivity (anaphylactic) reaction to any penicillin is a contraindication.
⚠️ Warnings ▾
WARNINGS: Serious and occasionally fatal hypersensitivity (anaphylactic) reactions have been reported in patients on penicillin therapy. These reactions are more likely to occur in individuals with a history of penicillin hypersensitivity and/or a history of sensitivity to multiple allergens. Before initiating therapy with nafcillin, careful inquiry should be made concerning previous hypersensitivity reactions to penicillins, cephalosporins, or other allergens.
If an allergic reaction occurs, nafcillin should be discontinued and appropriate therapy instituted. Clostridium difficile associated diarrhea (CDAD) has been reported with use of nearly all antibacterial agents, including Nafcillin for Injection, and may range in severity from mild diarrhea to fatal colitis. Treatment with antibacterial agents alters the normal flora of the colon leading to overgrowth of C. difficile .
C. difficile produces toxins A and B which contribute to the development of CDAD. Hypertoxin producing strains of C. difficile cause increased morbidity and mortality, as these infections can be refractory to antimicrobial therapy and may require colectomy. CDAD must be considered in all patients who present with diarrhea following antibiotic use.
Careful medical history is necessary since CDAD has been reported to occur over two months after the administration of antibacterial agents. If CDAD is suspected or confirmed, ongoing antibiotic use not directed against C. difficile may need to be discontinued. Appropriate fluid and electrolyte management, protein supplementation, antibiotic treatment of C. difficile , and surgical evaluation should be instituted as clinically indicated.
🤒 Adverse Reactions ▾
ADVERSE REACTIONS: 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, arthralgia, abdominal pain) and various skin rashes. Nausea, vomiting, diarrhea, stomatitis, black or hairy tongue, and other symptoms of gastrointestinal irritation may occur, especially during oral penicillin therapy. Local Reactions Pain, swelling, inflammation, phlebitis, thrombophlebitis, and occasional skin sloughing at the injection site have occurred with intravenous administration of nafcillin (see DOSAGE AND ADMINISTRATION ).
Severe tissue necrosis with sloughing secondary to subcutaneous extravasation of nafcillin has been reported. Nervous System Reactions Neurotoxic reactions similar to those observed with penicillin G could occur with large intravenous doses of nafcillin especially in patients with concomitant hepatic insufficiency and renal dysfunction (see PRECAUTIONS ). Nephrotoxicity Renal tubular damage and interstitial nephritis have been associated with the administration of nafcillin.
Manifestations of nephrotoxicity are hematuria, proteinuria, and acute kidney injury, and may be associated with rash, fever, and eosinophilia. The majority of cases resolve upon discontinuation of nafcillin. Some patients, however, may require dialysis treatment and may develop permanent renal damage.
Hepatic Reactions Elevation of liver transaminases and/or cholestasis may occur, especially with administration of high doses of nafcillin. Gastrointestinal Reactions Pseudomembranous colitis has been reported with the use of nafcillin. The onset of pseudomembranous colitis symptoms may occur during or after antibiotic treatment (see WARNINGS ).
Metabolic Reactions Agranulocytosis, neutropenia, and bone marrow depression have been associated with the use of nafcillin. To report SUSPECTED ADVERSE EVENTS, contact FDA at 1-800-FDA-1088 or www.fda.gov .
Nervous System Reactions Neurotoxic reactions similar to those observed with penicillin G could occur with large intravenous doses of nafcillin especially in patients with concomitant hepatic insufficiency and renal dysfunction (see PRECAUTIONS ).
Nephrotoxicity Renal tubular damage and interstitial nephritis have been associated with the administration of nafcillin. Manifestations of nephrotoxicity are hematuria, proteinuria, and acute kidney injury, and may be associated with rash, fever, and eosinophilia. The majority of cases resolve upon discontinuation of nafcillin. Some patients, however, may require dialysis treatment and may develop permanent renal damage.
Hepatic Reactions Elevation of liver transaminases and/or cholestasis may occur, especially with administration of high doses of nafcill…
🆘 Overdosage ▾
OVERDOSAGE Neurotoxic reactions similar to those observed with penicillin G may arise with intravenous doses of nafcillin especially in patients with concomitant hepatic insufficiency and renal dysfunction (see PRECAUTIONS ). In the case of overdosage, discontinue nafcillin, treat symptomatically and institute supportive measures as required. Hemodialysis does not increase the rate of clearance of nafcillin from the blood.
🧬 Clinical Pharmacology ▾
CLINICAL PHARMACOLOGY: In a study of five healthy adults administered a single 500 mg dose of nafcillin by intravenous injection over seven minutes, the mean plasma concentration of the drug was approximately 30 mcg/mL at 5 minutes after injection. The mean area under the plasma concentration-versus-time curve (AUC) for nafcillin in this study was 18.06 mcg • h/mL. The serum half-life of nafcillin administered by the intravenous route ranged from 33 to 61 minutes as measured in three separate studies.
In contrast to the other penicillinase-resistant penicillins, only about 30% of nafcillin is excreted as unchanged drug in the urine of normal volunteers, and most within the first six hours. Nafcillin is primarily eliminated by nonrenal routes, namely hepatic inactivation and excretion in the bile. Nafcillin binds to serum proteins, mainly albumin.
The degree of protein binding reported for nafcillin is 89.9 ± 1.5%. Reported values vary with the method of study and the investigator. The concurrent administration of probenecid with nafcillin increases and prolongs plasma concentrations of nafcillin.
Probenecid significantly reduces the total body clearance of nafcillin with renal clearance being decreased to a greater extent than nonrenal clearance. The penicillinase-resistant penicillins are widely distributed in various body fluids, including bile, pleural, amniotic and synovial fluids. With normal doses insignificant concentrations are found in the aqueous humor of the eye.
High nafcillin CSF levels have been obtained in the presence of inflamed meninges. Renal failure does not appreciably affect the serum half-life of nafcillin; therefore, no modification of the usual nafcillin dosage is necessary in renal failure with or without hemodialysis. Hemodialysis does not accelerate the rate of clearance of nafcillin from the blood.
A study which assessed the effects of cirrhosis and extrahepatic biliary obstruction in man demonstrated that the plasma clearance of nafcillin was significantly decreased in patients with hepatic dysfunction. In these patients with cirrhosis and extrahepatic obstruction, nafcillin excretion in the urine was significantly increased from about 30 to 50% of the administered dose, suggesting that renal disease superimposed on hepatic disease could further decrease nafcillin clearance. Pharmacokinetics Intramuscular injections of nafcillin sodium, USP 1 gram produced peak serum levels in 0.5 to 1 hour of 7.61 mcg/mL.
The degree of protein binding reported has been 89.9 +/-1.5%. With normal doses nafcillin is found in therapeutic concentrations in the pleural, bile, and amniotic fluids. Insignificant concentrations are found in the cerebrospinal fluid and aqueous humor.
Blood concentrations may be tripled by the concurrent use of probenecid. Clinical studies with nafcillin sodium in infants under three days of age and prematures have revealed higher blood levels and slower rates of urinary excretion than in older children and adults. A high concentration of nafcillin sodium is excreted via the bile.
About 30% of an intramuscular dose is excreted in the urine. Microbiology Penicillinase-resistant penicillins exert a bactericidal action against penicillin-susceptible microorganisms during the state of active multiplication. All penicillins inhibit the biosynthesis of the bacterial cell wall.
Nafcillin sodium has been shown to be active against most isolates of the following microorganism, both in vitro and in clinical infections as described in the INDICATIONS AND USAGE section. Gram-Positive Bacteria Staphylococcus aureus (Methicillin susceptible isolates only) Susceptibility Testing For specific information regarding susceptibility test interpretive criteria and associated test methods and quality control standards recognized by FDA for this drug, please see: https://www.fda.gov/STIC.
Pharmacokinetics Intramuscular injections of nafcillin sodium, USP 1 gram produced peak serum levels in 0.5 to 1 hour of 7.61…
📦 How Supplied / Storage and Handling ▾
HOW SUPPLIED: Nafcillin for Injection, USP contains nafcillin sodium equivalent to 1 gram or 2 grams of nafcillin and is supplied as follows: Product Code Unit of Sale Strength Each 302710 NDC 63323-327-10 Unit of 10 1 gram per vial NDC 63323-327-21 302820 NDC 63323-328-20 Unit of 10 2 grams per vial NDC 63323-328-21 The container closure is not made with natural rubber latex.
📦 Storage and Handling ▾
STORAGE: Before reconstitution store sterile powder at 20º to 25ºC (68º to 77ºF) [see USP Controlled Room Temperature].
📋 Description ▾
DESCRIPTION: Nafcillin for Injection, USP is a semisynthetic antibiotic penicillin derived from the penicillin nucleus, 6-aminopenicillanic acid. It is the sodium salt in a parenteral dosage form. The chemical name is 4-Thia-1-azabicyclo [3.2.0]heptane-2-carboxylic acid, 6-[[(2-ethoxy-1-naphthalenyl)carbonyl]amino]-3,3-dimethyl-7-oxo-monosodium salt, monohydrate [2S(2α,5α,6β)].
It is resistant to inactivation by the enzyme penicillinase (beta-lactamase). The structural formula of nafcillin sodium is as follows: C 21 H 21 N 2 NaO 5 S•H 2 O M.W. 454.47 Nafcillin for Injection, USP, for intramuscular or the intravenous route of administration, containing nafcillin sodium as a white crystalline powder for reconstitution.
It is soluble in water. The pH of the aqueous solution is 6.0 to 8.5. Nafcillin for Injection, USP contains nafcillin sodium as the monohydrate equivalent to 1 gram or 2 grams of nafcillin per vial.
The sodium content is 65.8 mg [2.9 mEq] per gram of nafcillin. The product is buffered with 40 mg sodium citrate per gram. structure