Dicloxacillin
Dicloxacillin is a penicillin-type antibiotic used to treat bacterial infections caused by penicillinase-producing staphylococci (staph bacteria that resist standard penicillin).
🧬 Where this information comes from Click to expand
The clinical label records used on this page are FDA-filed Structured Product Labeling (SPL) retrieved through openFDA. We identified 11 clinical label sets within the page’s selected clinical scope after exact ingredient or ingredient-combination matching and applicable route/form matching. Forms, routes, brands, labelers, strengths, and NDC product-record counts are built separately from matching FDA National Drug Code Directory records. The linked DailyMed document is a representative official source for verification, not the page’s only clinical source. View the linked label on DailyMed →
📖 Dicloxacillin: Patient Information Guide
A plain-language walkthrough of Dicloxacillin — what it treats, how it works, how it’s taken, side effects, warnings and interactions. Tap any section to expand it.
🎯What it's used for▾
Dicloxacillin is an antibiotic used specifically against staphylococcal (staph) infections caused by bacteria that produce penicillinase — an enzyme that destroys ordinary penicillin.
- Treatment of infections caused by penicillinase-producing staphylococci shown to be susceptible to the drug
- Initial (empiric) treatment of suspected resistant staph infections while lab results are pending
- Follow-up oral therapy after initial treatment with an injectable antibiotic, once the clinical condition allows
Dicloxacillin should not be used against organisms that are still susceptible to regular penicillin G, and should be stopped if lab results show the infection is not caused by a resistant staphylococcus. To protect antibiotic effectiveness for everyone, it should only be used for proven or strongly suspected susceptible bacterial infections.
⚙️How it works▾
Dicloxacillin kills bacteria by blocking the construction of their cell walls. All bacteria need a strong cell wall to hold their shape and survive. Dicloxacillin interferes with the enzymes responsible for building that wall, causing the bacteria to break apart and die. It's most effective when bacteria are actively growing and multiplying.
What makes dicloxacillin special is its resistance to penicillinase — the enzyme certain staph bacteria use to destroy regular penicillin. Because dicloxacillin isn't broken down by this enzyme, it stays active where ordinary penicillin would fail. However, staph bacteria that are resistant to oxacillin (methicillin-resistant strains, or MRSA) are also resistant to dicloxacillin.
💊How it's taken▾
Dicloxacillin Sodium capsules are taken by mouth. They should be taken on an empty stomach because food slows absorption. Always take capsules with a generous amount of water, and avoid lying down immediately after taking them to prevent irritation of the esophagus.
- The length of treatment depends on the type and severity of the infection — your prescriber will set the right duration
- Severe staph infections generally require at least 14 days of treatment; some infections like endocarditis or bone infections may need longer courses
- Do not stop early just because you feel better — finishing the full course matters for clearing the infection and preventing resistance
🤒Side effects — in detail▾
Most side effects from dicloxacillin are related to the stomach or allergic responses. Common ones include:
- Nausea, vomiting, or diarrhea
- Stomach irritation or upset
- Mouth sores or black/hairy tongue
- Skin rash or hives (mild allergic reaction)
- Esophageal burning or irritation (especially if not taken with enough water or if taken before bed)
- Mild, temporary increases in liver enzyme levels
Serious reactions — including severe allergic reactions (anaphylaxis), C. difficile-associated diarrhea (which can be severe or bloody), significant blood cell changes, or signs of liver or kidney problems — require immediate medical attention. Call your doctor or seek emergency care if any of these occur.
⚠️Warnings & precautions▾
- Severe allergic reactions (anaphylaxis): Rare but potentially fatal. Symptoms include throat swelling, difficulty breathing, hives, and a sudden drop in blood pressure. Tell your prescriber about any past penicillin or cephalosporin allergies before starting.
- C. difficile diarrhea: All antibiotics can disrupt normal gut bacteria and allow C. difficile (C. diff) to overgrow — causing diarrhea that can range from mild to life-threatening colitis. This can occur even up to 2 months after finishing the antibiotic.
- Esophageal injury: Taking capsules without enough water or lying down right after can cause esophageal burning or ulceration. Always take with a full glass of water and stay upright.
- Blood and liver effects: Rarely, dicloxacillin-class antibiotics have been linked to blood cell changes and liver enzyme elevations. Report unusual fatigue, bruising, or yellowing of the skin to your doctor.
🔀What it interacts with▾
Dicloxacillin can interact with several medications — let your prescriber and pharmacist know everything you take.
- Tetracycline antibiotics — can blunt dicloxacillin's bacteria-killing effect; avoid combining them
- Probenecid (a gout medication) — raises dicloxacillin levels in the blood by slowing its removal through the kidneys; sometimes used intentionally but requires medical oversight
- Aminoglycoside antibiotics (e.g., gentamicin, tobramycin) — dicloxacillin can chemically inactivate aminoglycosides if mixed together; they must always be given separately, and lab tests measuring aminoglycoside blood levels may be falsely low
- Warfarin or dicumarol (blood thinners) — dicloxacillin may reduce their anticoagulant (blood-thinning) effect; your doctor should monitor your clotting time (prothrombin time) and adjust doses if needed
This is not a complete list of interactions. Always talk with your doctor or pharmacist before starting, stopping, or changing any medication.
📋Before taking it▾
- Do not take dicloxacillin if you have ever had a serious allergic reaction to any penicillin antibiotic
- Tell your doctor if you have had allergic reactions to cephalosporin antibiotics — cross-reactions are possible
- Mention any kidney or liver problems, as these can affect how the drug is processed and cleared
- Tell your doctor all medications you take — especially tetracyclines, probenecid, aminoglycoside antibiotics, and blood thinners like warfarin
- Tell your prescriber if you are pregnant, planning to become pregnant, or breastfeeding
📡Pharmacodynamics — effects in the body▾
Dicloxacillin works by interfering with the synthesis (construction) of bacterial cell walls, which bacteria need to survive. This bactericidal (bacteria-killing) action happens during the phase when bacteria are actively multiplying. It is active against most isolates of Staphylococcus species — specifically those that produce penicillinase — both in lab testing and in clinical infections.
🔬Pharmacokinetics — how your body processes it▾
After taking dicloxacillin by mouth, it is absorbed fairly quickly but not completely — peak blood levels are reached in about 1 to 1.5 hours. Food delays this absorption, which is why it should be taken on an empty stomach. Dicloxacillin binds heavily to proteins in the blood (about 98%), and it does not reach meaningful levels in the brain or eyes at normal doses. It is cleared from the body quickly — the elimination half-life (the time it takes the body to clear half the drug) is about 0.7 hours — primarily through the kidneys, with some removal through the liver and bile.
📦How to store it▾
Store at 20° to 25°C (68° to 77°F); excursions permitted to 15° to 30°C (59° to 86°F) . Dispense in a tight, light-resistant container as defined in the USP, with a child-resistant closure (as required).
📄 Written from Dicloxacillin’s FDA-approved label information, summarized in plain language with AI, and reviewed by our pharmacy team before publication. Every point is grounded in that labeling — nothing is invented. How we use AI →
Supplements & herbs that interact with Dicloxacillin
56 supplements and herbal products have documented interactions with Dicloxacillin in the licensed clinical database we use. Most are manageable — but your pharmacist should know about everything you take, including vitamins and herbals.
- Major · 3
- Moderate · 42
- Minor · 11
Educational information from a licensed clinical database (Natural Medicines) — see our data sources & update cadence. Not medical advice: an interaction being documented does not mean it will happen to you; do not start or stop medications or supplements without professional guidance.
Nutrient depletion considerations
Dicloxacillin has been associated with lower levels of 8 nutrients in the clinical literature. This does not mean a deficiency will occur — it means these may be worth discussing with your pharmacist or healthcare provider, especially with long-term use.
- Higher significance · 6
- Moderate · 2
Educational information from a licensed clinical database (Natural Medicines) — not medical advice. Do not start or stop medications or supplements without professional guidance.
🩺 Pharmacist Counseling Corner
Quick, plain-English answers to the questions patients ask most about Dicloxacillin — the kind of thing our pharmacy team would talk through with you at the counter.
What kind of infections does dicloxacillin actually treat? ▾
Does it matter if I take it with food? ▾
Can I stop taking it once I feel better? ▾
What side effects should I actually worry about versus just put up with? ▾
I take warfarin for my heart. Is it safe to take dicloxacillin at the same time? ▾
I had a reaction to amoxicillin years ago — can I take dicloxacillin? ▾
Is Dicloxacillin available over the counter? ▾
When was Dicloxacillin first available? ▾
Who makes Dicloxacillin? ▾
💬 Answers drafted from Dicloxacillin’s FDA-approved label information, summarized in plain language with AI, and reviewed by our pharmacy team before publication. Grounded in that labeling — nothing is made up. How we use AI →
🧰 Keep exploring
💊 How Dicloxacillin comes
Dicloxacillin is available in 1 form. Different forms and brands can have different approved uses, doses, schedules, and directions. Follow the instructions for your exact product, and do not switch forms without guidance from your prescriber or pharmacist.
Capsule
How this form is used
- Dicloxacillin Sodium capsules are used to treat infections caused by penicillinase-producing staphylococci confirmed or strongly suspected to be susceptible to the drug
- Dicloxacillin Sodium capsules may be used to start treatment for suspected resistant staph infections while awaiting lab results
- Dicloxacillin Sodium capsules are not appropriate for serious, life-threatening infections as initial therapy — oral treatment may follow after initial treatment with an injectable antibiotic
- Dicloxacillin Sodium capsules should be taken on an empty stomach — food delays absorption
- Dicloxacillin Sodium capsules should be swallowed with a full glass of water; do not take them right before lying down to avoid esophageal irritation
- Complete the full prescribed course — duration depends on infection type and severity and is determined by your prescriber
- For severe staph infections, Dicloxacillin Sodium capsules are typically continued for at least 14 days and for at least 48 hours after symptoms and cultures clear
📊 Dicloxacillin across the U.S. market
How Dicloxacillin appears in the FDA’s National Drug Code Directory — including its dosage forms, strengths, brand names, manufacturers, and FDA-listed product records. These are directory records, not sales or prescription volume.
Also listed with the FDA, not a patient dose form: Powder (1) — bulk drug substance sold to compounders/manufacturers and multi-item kits. These aren’t counted in the dose-form total above.
Share of FDA-listed product records by manufacturer — FDA National Drug Code Directory. Record counts are not sales or prescription volume.
📈 How widely Dicloxacillin is used
A general measure of how commonly Dicloxacillin is prescribed, based on Medicaid — one of the largest public drug programs. The figure below is prescriptions filled in Q1–Q4 2025, summed across every form and brand of the drug.
Think of this as a proxy for how widely Dicloxacillin is used, drawn from freely available public data. Medicaid is just one program — these numbers don’t include Medicare, other government coverage, or commercial and cash-pay prescriptions, so real-world use is higher than what’s shown here.
How commonly is Dicloxacillin prescribed? Of the 1,597 medications we measure, Dicloxacillin ranks #718 by Medicaid prescriptions — more than 55% of them.
Utilization by Dicloxacillin product
Pick a product to see its own Medicaid numbers. Each chip is one clinical product — a specific strength & dosage form as defined by RxNorm — with brand-name and generic versions combined.
dicloxacillin 500 MG Oral Capsule Most dispensed
Summed across the 2 of 28 listed NDC products with Medicaid activity — every brand and generic of this exact strength & form. RxNorm 197596
dicloxacillin 250 MG Oral Capsule
Summed across the 2 of 27 listed NDC products with Medicaid activity — every brand and generic of this exact strength & form. RxNorm 197595
Shares are of the Medicaid prescriptions shown here. Product grouping follows RxNorm (the National Library of Medicine’s drug terminology), so “one product” means one strength & dosage form regardless of manufacturer. Dollar figures are gross Medicaid reimbursement before mandatory rebates — rebates (often large, especially for brand-name drugs) are confidential, so actual net cost to Medicaid is lower than shown.
Source: Medicaid State Drug Utilization Data (CMS), aggregated by generic ingredient — summed across every NDC (all brands, strengths, salt forms and dosage forms) of Dicloxacillin, and across all states and both fee-for-service and managed-care claims. A general popularity signal; it excludes Medicare, commercial insurance and cash prescriptions, so it is not total U.S. use. Based on the 4 of 55 listed Dicloxacillin NDCs with Medicaid activity.
🔍 Compare Dicloxacillin products
A representative set of FDA-listed product records for Dicloxacillin — across manufacturers, strengths, and dosage forms, grouped by form with each product’s manufacturer and how the FDA approved it. The same medicine may be made and packaged by different companies, so a single drug can have many directory entries. (It’s also why a refill can look different — a new shape, color, or box — even though it contains the same medication.)
| Strength | Route | Manufacturer / Labeler | Category ⓘ | Details |
|---|---|---|---|---|
| 💊Capsule | ||||
| 250 mg | Oral | A-S Medication Solutions × 2 listings | ANDA | View NDC → |
| 500 mg | Oral | A-S Medication Solutions | ANDA | View NDC → |
| 500 mg | Oral | Asclemed USA, Inc. | ANDA | View NDC → |
| 250 mg | Oral | Aurobindo Pharma Limited × 2 listings | ANDA | View NDC → |
| 500 mg | Oral | Aurobindo Pharma Limited × 2 listings | ANDA | View NDC → |
| 500 mg | Oral | Bryant Ranch Prepack × 2 listings | ANDA | View NDC → |
| 250 mg | Oral | Chartwell RX, LLC | ANDA | View NDC → |
| 500 mg | Oral | Chartwell RX, LLC | ANDA | View NDC → |
| 500 mg | Oral | NuCare Pharmaceticals, Inc. | ANDA | View NDC → |
| 250 mg | Oral | PD-Rx Pharmaceuticals, Inc. × 6 listings | ANDA | View NDC → |
| 500 mg | Oral | PD-Rx Pharmaceuticals, Inc. × 3 listings | ANDA | View NDC → |
| 500 mg | Oral | Redpharm Drug | ANDA | View NDC → |
| 500 mg | Oral | RedPharm Drug, Inc. | ANDA | View NDC → |
| 250 mg | Oral | Sandoz Inc | ANDA | View NDC → |
| 500 mg | Oral | Sandoz Inc | ANDA | View NDC → |
| 250 mg | Oral | Teva Pharmaceuticals USA, Inc. × 2 listings | ANDA | View NDC → |
| 500 mg | Oral | Teva Pharmaceuticals USA, Inc. × 2 listings | ANDA | View NDC → |
| 💊Bulk drug substance | ||||
| 50 kg/50 kg | — | Aurobindo Pharma Limited | BULK INGREDIENT | View NDC → |
Showing 31 of 31 products — FDA National Drug Code Directory. See every product, package size and price: browse all 31 Dicloxacillin NDCs →
📈 What people report — real-world data (FDA FAERS)
After a medicine reaches the market, patients, doctors and drugmakers can send the FDA reports of problems they think may be linked to it. Here’s what’s been reported for Dicloxacillin — a signal of what to watch for, not proof the drug caused it.
Source: openFDA, from the FDA Adverse Event Reporting System (FAERS). These are voluntary reports — they don’t prove the drug caused the effect, and counts reflect how often something was reported, not how often it actually happens. Reports also often name the very problem the medicine is taken for — a common reason to file one is that the drug didn’t help — so for a pain reliever you may see “pain” high on the list; that points to why the report was filed, not to the drug causing the symptom. This counts every report that lists Dicloxacillin in any role, so the total runs higher than the FDA’s official dashboard, which counts only cases where the drug is the suspect. For the authoritative figures, see the FDA FAERS Public Dashboard. Always talk to your pharmacist or doctor.
🏛️ The road to your pharmacy
How Dicloxacillin went from FDA review to the pharmacy shelf — the key milestones in its regulatory journey.
Source: Drugs@FDA.
🚨 Recall history
A recall is when a specific batch of a medicine is pulled from the market — usually a manufacturing issue, not a problem with the drug itself. Class I is most serious, Class III least.
Source: openFDA drug enforcement (recall) reports.
RxNorm Concept Web — From Ingredient to Every Form and Strength
This page starts with one ingredient concept (IN). The branches below show its dose-form concepts (SCDF), then the available clinical drug and strength concepts (SCD). Combination products remain separate concepts with their own pages.
RxCUI 3356 2 dose forms · 4 strengths
-
Dose form (SCDF) Oral Capsule RxCUI 371805In current FDA listings -
Dose form (SCDF) Oral Suspension RxCUI 371807No current FDA listingClinical drug / strength (SCD) 12.5 MG/MLRxCUI 313945
Look up RxCUI 3356 in the RxCUI Atlas →
RxNorm is the U.S. National Library of Medicine’s normalized drug vocabulary. Its concept hierarchy can include forms that are not currently marketed; the status on each branch compares that concept with current FDA listings. RxCUIs identify vocabulary concepts, not individual packages or manufacturers.
📦 Supply & shortage status
Whether Dicloxacillin is in short supply in the U.S. right now, plus any shortage history the FDA has on record. A shortage usually reflects a manufacturing or demand issue — not a safety problem with the drug.
Source: openFDA, from the FDA Drug Shortages database.
🏷️ Sold under these brand names
🏭 Manufacturers & labelers
RxNorm drug class
Dicloxacillin belongs to the Penicillin-class Antibacterial class.
Classified by RxNorm RxClass — the U.S. National Library of Medicine's standardized drug-classification service (Established Pharmacologic Class from the FDA, the ATC drug family from the WHO, and mechanism of action). Reference only, not medical advice.
🔬 Where this comes from
Core label, product, RxNorm, safety, and utilization data on this page come from the sources identified below. AI-written, editorial, and licensed sections are labeled separately.
How we combine label and product data
HelloPharmacist combines public FDA and NLM records; we don’t author the underlying clinical facts. We identified 11 FDA-filed SPL label sets within the page’s selected clinical scope after exact ingredient or ingredient-combination matching and applicable route/form matching. The representative label is the starting point for the displayed reference monograph; the 12 largest stored in-scope SPL records, which may include that representative, are compared section by section, and the longest available version of each section is retained. Forms, routes, brands, labelers, product-listed strengths, and product-record counts are aggregated separately from ingredient-matched FDA NDC Directory records; package records listed above are associated with the linked SPL; and the normalized concept hierarchy comes from NLM RxNorm.
For canonical ingredient pages, bounded product-attributed indication and administration excerpts may be added to the AI evidence, and the generator is instructed to preserve available product, brand, route, and form qualifiers instead of treating one label as universal. Where a section is identified as AI-written, its plain-language text is generated from bounded label evidence. New draft drug pages remain in the admin review queue before first publication. Aurobindo Pharma Limited is the representative DailyMed label linked for verification and dates; it is not the sole source used for the page.
This is general education, not medical advice — always consult your doctor or pharmacist about your medications and any medical condition. For the exact wording of the linked representative label, view that label on DailyMed; some displayed composite sections may come from other in-scope SPL labels. Learn how we use AI and our data sources & update cadence.