Comprehensive medication guide to Dicloxacillin including estimated pricing, availability information, side effects, and how to find it in stock at your local pharmacy.
Estimated Insurance Pricing
$0-$20 copay for generic dicloxacillin; Tier 1-2 on most commercial insurance, Medicare Part D, and Medicaid plans. Prior authorization is rarely required for short antibiotic courses.
Estimated Cash Pricing
$70-$115 retail for a standard 10-day course (40 capsules, 500 mg); as low as $21.87-$27.75 with a GoodRx coupon or $40.20 with SingleCare — approximately 62-71% off retail price.
Medfinder Findability Score
78/100
Summarize with AI
On this page
Dicloxacillin is a prescription antibiotic in the penicillin family, specifically classified as a penicillinase-resistant penicillin (also called an isoxazolyl penicillin). It was patented in 1961 and approved by the FDA for medical use in 1968. The brand name Dynapen has been discontinued; all Dicloxacillin available today is generic (dicloxacillin sodium).
Dicloxacillin is indicated for infections caused by penicillinase-producing staphylococci — primarily methicillin-susceptible Staphylococcus aureus (MSSA). It is commonly prescribed for skin and soft tissue infections including cellulitis, impetigo, folliculitis, boils, carbuncles, and mastitis, as well as bone infections caused by susceptible staphylococci.
Dicloxacillin is not effective against MRSA (methicillin-resistant Staphylococcus aureus), Gram-negative bacteria, or viral infections. It is available as oral capsules (250 mg and 500 mg) and as a powder for oral suspension.
We have a 99% success rate finding medications, even during nationwide shortages.
Need this medication?
Like all penicillin antibiotics, Dicloxacillin is bactericidal — it kills bacteria rather than just slowing their growth. It works by blocking an enzyme called penicillin-binding protein (PBP), which bacteria need to build and repair their cell walls. Without a functional cell wall, bacteria cannot maintain their structure and ultimately burst and die.
What makes Dicloxacillin special is its resistance to beta-lactamase (penicillinase) enzymes that many staph bacteria produce to destroy ordinary penicillin. The isoxazolyl group in Dicloxacillin's chemical structure creates steric hindrance that physically blocks the enzyme from breaking down the antibiotic — allowing it to pass through intact and reach its target.
Dicloxacillin is rapidly absorbed after oral dosing, reaching peak blood concentrations within 1-1.5 hours. It has a short half-life of approximately 0.7 hours and is about 98% protein-bound. It is excreted primarily by the kidneys and must be taken four times daily (every 6 hours) to maintain effective blood levels throughout the treatment course.
250 mg — capsule
Typically used for mild infections or pediatric dosing
500 mg — capsule
Standard adult dose for skin and soft tissue infections; most commonly prescribed strength
62.5 mg/5 mL — oral suspension
Liquid form for patients who cannot swallow capsules; primarily used in pediatric dosing
Dicloxacillin is not currently listed on the FDA's official Drug Shortages Database, and ASHP has not issued an active shortage bulletin. However, patients consistently report difficulty finding it at local pharmacies. Dicloxacillin's niche prescribing volume means most pharmacies maintain only minimal stock — one or two filled prescriptions can exhaust a location's supply.
The brand-name Dynapen has been discontinued, leaving only a small number of generic manufacturers supplying the market. Independent pharmacies and hospital-affiliated outpatient pharmacies tend to have better access through secondary wholesalers and institutional purchasing.
If your local pharmacy doesn't have Dicloxacillin in stock, medfinder can call nearby pharmacies on your behalf to find which ones have it available, and will text you the results — saving you from making calls while you're sick.
Dicloxacillin is not a controlled substance, so any licensed prescriber can order it without special DEA authority. It is widely prescribed across multiple specialty types.
Primary care physicians (family medicine, internal medicine)
Urgent care providers
Dermatologists
Pediatricians
Orthopedic surgeons (for bone infections)
Infectious disease specialists
Nurse practitioners (NPs) and physician assistants (PAs)
Dicloxacillin can be prescribed through telehealth for uncomplicated skin infections. Platforms including Teladoc, MDLive, and Amazon Clinic can issue same-day electronic prescriptions that are sent directly to your pharmacy, making access convenient for patients who cannot visit a clinic in person.
No. Dicloxacillin is not a controlled substance and is not scheduled by the Drug Enforcement Administration (DEA). It is a standard prescription antibiotic with no abuse potential.
Any licensed prescriber can prescribe Dicloxacillin without special DEA authorization — including primary care physicians, urgent care providers, nurse practitioners, physician assistants, and specialists. There are no quantity limits, mandatory monitoring requirements, or special refill restrictions tied to controlled substance scheduling. Prescriptions can be sent electronically, by phone, or in writing to any pharmacy.
Most patients tolerate Dicloxacillin well. Common side effects are primarily gastrointestinal:
Diarrhea
Nausea
Skin rash or hives
Yeast infections (oral or vaginal candidiasis)
Transient elevation of liver enzymes (usually asymptomatic)
Severe allergic reaction / anaphylaxis (difficulty breathing, facial swelling, hives) — call 911
Cholestatic hepatitis / jaundice (yellowing of skin or eyes, dark urine) — rare, ~1 in 15,000 exposures; can occur weeks after stopping the drug
Kidney damage (decreased urination, swelling, extreme fatigue)
Seizures (rare; more common with high doses or kidney disease)
C. diff colitis (severe watery diarrhea with fever or cramping)
Blood disorders (eosinophilia, hemolytic anemia, bone marrow depression — rare)
Know what you need? Skip the search.
Cephalexin (Keflex)
First-generation cephalosporin; clinically equivalent to Dicloxacillin for MSSA skin infections; universally available; twice-daily dosing; can be taken with food
Clindamycin
Covers MSSA and many MRSA strains; useful for penicillin-allergic patients; monitor for C. diff; three times daily dosing
TMP-SMX (Bactrim/Septra)
Covers both MSSA and MRSA; preferred for purulent infections in high-MRSA areas; twice daily; avoid in sulfa-allergic patients
Amoxicillin-Clavulanate (Augmentin)
Broader spectrum; useful for mixed infections (e.g., animal bites); more GI side effects; not MRSA-active
Prefer Dicloxacillin? We can find it.
Doxycycline / Tetracyclines
majorTetracyclines reduce Dicloxacillin's effectiveness by slowing bacterial growth (bacteriostatic vs bactericidal antagonism). Avoid concurrent use unless directed by specialist.
BCG Vaccine / Cholera Vaccine
majorDicloxacillin can kill the live bacteria in these vaccines, rendering them ineffective. Do not administer live bacterial vaccines during antibiotic therapy or within 14 days of completion.
Warfarin
moderateDicloxacillin may enhance warfarin's anticoagulant effect, increasing bleeding risk. Monitor INR closely and report any unusual bruising or bleeding.
Hormonal Contraceptives
moderateDicloxacillin may reduce effectiveness of birth control pills, patches, rings, and injections through CYP3A4 induction and gut flora changes. Use backup contraception during treatment and for one full cycle afterward.
Probenecid
moderateProbenecid slows renal excretion of Dicloxacillin, increasing blood levels. May be used intentionally to boost levels but requires dose adjustment monitoring.
Pacritinib
majorDicloxacillin induces CYP3A4 and can reduce pacritinib blood levels, potentially reducing its efficacy. Avoid concurrent use.
Colestipol
minorColestipol binds to Dicloxacillin in the gut and reduces absorption. Take Dicloxacillin 1-2 hours before or 4-6 hours after colestipol.
Dicloxacillin is a highly effective, narrow-spectrum antibiotic for MSSA skin and soft tissue infections. Its targeted mechanism makes it an appropriate first-line choice when staph is the suspected or confirmed pathogen and MRSA is unlikely. It is well-established, has a favorable safety profile for short courses, and is available as an affordable generic.
The main practical challenge for patients is finding it in stock. Because Dicloxacillin is a niche generic, many pharmacies keep minimal inventory. Patients may need to check multiple locations before finding one that can fill their prescription same-day.
If you're having trouble finding Dicloxacillin, medfinder can call local pharmacies on your behalf and text you which ones have your prescription available. For those who cannot find it at all, cephalexin is the most commonly recommended clinical equivalent — equally effective for MSSA skin infections and universally stocked at all pharmacies.
Medfinder Editorial Standards
Our medication guides are researched and written to help patients make informed decisions. All content is reviewed for accuracy and updated regularly. Learn more about our standards
ChatGPT
Claude
Perplexity
Grok
Gemini