In ATCC 25923 and E19977, the dicloxacillin EC50 values are 0.06 and 0.50 mg/L, respectively. At pH 7.4, the minimum inhibitory concentrations of dicloxacillin in ATCC 25923 and E19977 are 0.125 and 0.5 mg/L, respectively [2].

In a mouse model of peritonitis sepsis, dicloxacillin had therapeutic efficacy, and all of the mice made it through [3].

Animal/Disease Models: Female outbred Swiss Webster mice (murine peritonitis sepsis model) [3].
Doses: 125 mg/kg. Mode of
Route of Administration: intravenous (iv) (iv)injection, single dose.
Experimental Results: All mice survived.

Absorption, Distribution and Excretion
Absorption of the isoxazolyl penicillins after oral administration is rapid but incomplete: peak blood levels are achieved in 1-1.5 hours. Oral absorption of cloxacillin, dicloxacillin, oxacillin and nafcillin is delayed when the drugs are administered after meals.
Dicloxacillin sodium is rapidly excreted as unchanged drug in the urine by glomerular filtration and active tubular secretion.
Differences in the elimination, distribution, and absorption of dicloxacillin and cloxacillin were studied in a group of healthy individuals with the use of a 2-compartment model. In patients on chronic intermittent hemodialysis, only dicloxacillin was investigated and the results were compared with data obtained in earlier studies on cloxacillin and flucloxacillin. In healthy volunteers the bioavailability after oral administration of 2 g dicloxacillin or 2 g cloxacillin amounted to 48.8% and 36.9% of the dose, respectively, when calculated from the area under the serum concentration-time curve, and to 74.1% and 48.5%, respectively, when calculated from the urinary excretion. Individual variation in bioavailability after oral administration was slightly lower for docloxacillin than for cloxacillin. The higher serum concentrations of dicloxacillin, as compared with cloxacillin, are also attributable to slower (renal) elimination (T 1/2: 42 and 33 min, respectively). Analysis of serum concentrations after intravenous administration of 1 and 2 g dicloxacillin to healthy subjects revealed concentration-dependent kinetics with respect ot renal elimination. In hemodialysis patients the elimination rate of dicloxacillin (T 1/2: 129 min) corresponds with the extrarenal elimination rate in healthy subjects. The bioavailability after oral administration of 1 g in patients is good (75.9% of the dose).
Dicloxacillin, a semisynthetic isoxazolyl penicillin antibiotic, has antimicrobial activity against a wide variety of gram-positive bacteria including Staphylococcus aureus, Streptococcus pyogenes, Streptococcus pneumonia, Streptococcus epidermidis, Streptococcus viridans, Streptococcus agalactiae, and Neisseria meningitidis. The objective of this study was to evaluate the safety and pharmacokinetic profile of dicloxacillin after single and multiple oral dose in healthy Chinese volunteers. A single-center, open-label, randomized, two-phase study was conducted in 16 subjects. In the single-dose phase, subjects were randomly assigned to receive single doses of 0.25, 0.5, 1.0, and 2.0 g of dicloxacillin sodium capsule in a 4-way crossover design with a 5-day washout period between administrations. In the multiple-dose phase, subjects were assigned to receive 0.25 or 0.5 g every 6 hours for 3 days in a 2-way crossover design. Plasma and urine pharmacokinetic samples were assayed by a validated high-performance liquid chromatography-tandem mass spectrometry method. Pharmacokinetic parameters were calculated and analyzed statistically. Safety assessments were conducted throughout the study. Following a single oral dose of 0.25-2.0 g dicloxacillin sodium, the maximum plasma drug concentration (Cmax) and the corresponding values for the area under the concentration- time curve from 0 to 10 hours (AUC0-10 hr) increased in a dose-proportional manner. The mean elimination half-life (t1/2) was in the range of 1.38-1.71 hours. Dicloxacillin was excreted in its unchanged form via the kidney, with no tendency of accumulation, and varied from 38.65% to 50.10%. No appreciable accumulation of drug occurred with multiple oral doses of dicloxacillin. No serious adverse events were reported. Adverse events were generally mild. Dicloxacillin was safe and well tolerated in the volunteers and displayed linear increases in the Cmax and AUC0-10 hr values.
The purpose of antibiotic treatment in pregnant women is to treat the mother and/or the fetus since it is known that antibiotics administered to the mother cross the placenta and reach the fetus. A comparison of the drug concentration in maternal and fetal plasma gives an indication of the exposure of the fetus to the maternally administered antibiotics. The aim of this study was to review the literature pertaining to the placental transfer of antibiotics in man and to classify the antibiotics according to the type of transfer involved ... 3 types of placental transfers were identified. A few antibiotics cross the placenta rapidly and equilibrate in the maternal and cord plasma; this type of transfer is termed "complete" and include the antibiotics ampicillin, methicillin, cefmenoxime and cefotiam. Antibiotics which show incomplete transfer to the placenta where concentrations are lower in the cord than maternal plasma are said to have "incomplete" transfer and these include azlocillin, dicloxacillin, piperacillin, sulbenicillin, cefoxitin, amikacin, gentamicin, kanamycin, streptomycin, fosfomycin, thiamphenicol, griseofulvin, vancomycin and colistimethate. ... All examined antibiotics cross the human placenta including those with a molecular weight greater than 1000 kDa such as vancomycin and colistimethate but there are 3 distinct types of placental transfer: complete, incomplete and exceeding and most antibiotics exhibit incomplete transfer.
/The objective of the study was/ to determine whether upregulation of P-glycoprotein is responsible for the enhanced renal clearance of dicloxacillin in patients with cystic fibrosis ... Eleven patients with cystic fibrosis and 11 age-matched healthy volunteers /were used/. All subjects received a single oral dose of dicloxacillin 500 mg alone, dicloxacillin 500 mg plus probenecid (an organic anion transport inhibitor) 1 g, and dicloxacillin 500 mg plus cyclosporine (a P-glycoprotein inhibitor) 5 mg/kg; each treatment was separated by a washout period of 48 hours. A bolus dose of iothalamate meglumine 456 mg was administered on each study day as a marker of glomerular filtration. Blood and urine samples were taken serially up to 6 hours after each dose. Pharmacokinetics of dicloxacillin and iothalamate were determined by using compartmental and noncompartmental methods. Quantitative polymerase chain reaction was performed on peripheral blood mononuclear cells to measure expression of multidrug resistance 1 (MDR1) messenger RNA (mRNA). Genotyping for ABCB1 was performed to determine the presence of single nucleotide polymorphisms (exons 21 and 26). In both healthy subjects and patients with cystic fibrosis, compared with dicloxacillin alone, coadministration with probenecid produced a significantly lower renal clearance of dicloxacillin, whereas coadministration with cyclosporine resulted in no significant change; renal clearance was not significantly different between the two study groups. No correlation was found between MDR1 mRNA expression and renal clearance of dicloxacillin. The renal excretion of dicloxacillin was significantly greater in subjects with the ABCB1 exon 26 TT polymorphism when compared with subjects with the CT genotype. We found no significant difference in the pharmacokinetics of dicloxacillin between patients with cystic fibrosis and healthy volunteers. Renal clearance of dicloxacillin was significantly reduced in the presence of probenecid but not with cyclosporine, suggesting that the rate-limiting step in tubular secretion of dicloxacillin is uptake mediated by the organic anion transporter, and not P-glycoprotein inhibition.
For more Absorption, Distribution and Excretion (Complete) data for Dicloxacillin (22 total), please visit the HSDB record page.

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Metabolism / Metabolites
Dicloxacillin is partially metabolized to active and inactive metabolites. In one study following administration of a single 500-mg oral dose of dicloxacillin, 10% of the absorbed drug was hydrolyzed to penicilloic acids which are microbiologically inactive. Dicloxacillin is also hydroxylated to a small extent to a microbiologically active metabolite which appears to be slightly less active than dicloxacillin.

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Biological Half-Life
The elimination half-life for dicloxacillin is about 0.7 hour.
... In hemodialysis patients the elimination rate of dicloxacillin (T 1/2: 129 min) corresponds with the extrarenal elimination rate in healthy subjects ...
... Following a single oral dose of 0.25-2.0 g dicloxacillin sodium, the maximum plasma drug concentration (Cmax) and the corresponding values for the area under the concentration- time curve from 0 to 10 hours (AUC0-10 hr) increased in a dose-proportional manner. The mean elimination half-life (t1/2) was in the range of 1.38-1.71 hours ...
The serum half-life of dicloxacillin in adults with normal renal function is 0.6-0.8 hours. In one study in children 2-16 years of age, the serum half-life of the drug averaged 1.9 hours.
The serum half-life of dicloxacillin is slightly prolonged in patients with impaired renal function and has been reported to range from 1-2.2 hours in patients with severe renal impairment.

Hepatotoxicity
Dicloxacillin therapy has not been associated with serum enzyme elevations during treatment, but has been linked to rare instances of clinically apparent, cholestatic hepatitis. The typical time to onset is 1 to 6 weeks and the pattern of serum enzyme elevations is usually cholestatic, although cases with a mixed pattern have also been described (Case 1). The injury usually presents with jaundice and pruritus. Fever, rash and eosinophilia can occur, but are not prominent and autoantibodies are rarely detected. A similar pattern of injury occurs more frequently with flucloxacillin (also called floxacillin) and cloxacillin, two oral isoxazolyl penicillins similar in structure and activity to dicloxacillin, but never approved for use or available in the United States. Similar cholestatic hepatitis arising 1 to 6 weeks after starting therapy occurs with other penicillins.
Likelihood score: B (highly likely but rare cause of clinically apparent liver injury).

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Effects During Pregnancy and Lactation
◉ Summary of Use during Lactation
Limited information indicates that dicloxacillin levels in milk are very low and are not expected to cause adverse effects in breastfed infants. It is frequently used to treat mastitis in nursing mothers. Occasionally disruption of the infant's gastrointestinal flora, resulting in diarrhea or thrush have been reported with penicillins, but these effects have not been adequately evaluated. Dicloxacillin is acceptable in nursing mothers.
◉ Effects in Breastfed Infants
Relevant published information was not found as of the revision date.
◉ Effects on Lactation and Breastmilk
Relevant published information was not found as of the revision date.

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Protein Binding
Binds to serum protein, mainly albumin.

[1]. In vitro activity effects of combinations of cephalothin, dicloxacillin, imipenem, vancomycin and amikacin against methicillin-resistant Staphylococcus spp. strains. Ann Clin Microbiol Antimicrob. 2006 Oct 12;5:25.

[2]. Intra- and extracellular activities of dicloxacillin against Staphylococcus aureus in vivo and in vitro. Antimicrob Agents Chemother. 2010 Jun;54(6):2391-400.

[3]. Discovery of MRSA active antibiotics using primary sequence from the human microbiome. Nat Chem Biol. 2016 Dec;12(12):1004-1006.

Dicloxacillin is a penicillin that is 6-aminopenicillanic acid in which one of the amino hydrogens is replaced by a 3-(2,6-dichlorophenyl)-5-methyl-1,2-oxazol-4-yl]formyl group. It has a role as an antibacterial drug. It is a penicillin and a dichlorobenzene. It is a conjugate acid of a dicloxacillin(1-).
One of the penicillins which is resistant to penicillinase.
Dicloxacillin is a Penicillin-class Antibacterial.
Dicloxacillin is an oral, second generation penicillin antibiotic that is used to treat bacterial infections caused by penicillinase-resistant staphylococci. Dicloxacillin has been linked to rare instances of clinically apparent, idiosyncratic liver injury.
Dicloxacillin has been reported in Bos taurus with data available.
Dicloxacillin is a broad-spectrum, semi-synthetic, beta-lactam, penicillin antibiotic with bactericidal and beta-lactamase resistant activity. Dicloxacillin binds to penicillin binding proteins (PBP) located on the inner membrane of the bacterial cell wall. It also inhibits the cross-linkage of peptidoglycan, a critical component of bacterial cell walls. This leads to the inhibition of bacterial cell wall synthesis and eventually causes cell lysis.
One of the PENICILLINS which is resistant to PENICILLINASE.

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Drug Indication
Used to treat infections caused by penicillinase-producing staphylococci which have demonstrated susceptibility to the drug.

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Mechanism of Action
Dicloxacillin exerts a bactericidal action against penicillin-susceptible microorganisms during the state of active multiplication. All penicillins inhibit the biosynthesis of the bacterial cell wall. By binding to specific penicillin-binding proteins (PBPs) located inside the bacterial cell wall, dicloxacillin inhibits the third and last stage of bacterial cell wall synthesis. Cell lysis is then mediated by bacterial cell wall autolytic enzymes such as autolysins; it is possible that dicloxacillin interferes with an autolysin inhibitor.

C19H17CL2N3O5S

470.33

469.026

3116-76-5

Dicloxacillin Sodium hydrate;13412-64-1;Dicloxacillin-13C4

18381

Typically exists as solid at room temperature

1.6±0.1 g/cm3

692.4±55.0 °C at 760 mmHg

372.5±31.5 °C

0.0±2.3 mmHg at 25°C

1.691

3.02

2

7

4

30

746

3

CC1=C(C(N[C@@H]2C(N3[C@H](C(C)(S[C@H]23)C)C(O)=O)=O)=O)C(C4=C(Cl)C=CC=C4Cl)=NO1

YFAGHNZHGGCZAX-JKIFEVAISA-N

InChI=1S/C19H17Cl2N3O5S/c1-7-10(12(23-29-7)11-8(20)5-4-6-9(11)21)15(25)22-13-16(26)24-14(18(27)28)19(2,3)30-17(13)24/h4-6,13-14,17H,1-3H3,(H,22,25)(H,27,28)/t13-,14+,17-/m1/s1

(2S,5R,6R)-6-[[3-(2,6-dichlorophenyl)-5-methyl-1,2-oxazole-4-carbonyl]amino]-3,3-dimethyl-7-oxo-4-thia-1-azabicyclo[3.2.0]heptane-2-carboxylic acid

Dicloxacilline Dicloxacilina Dicloxacillin

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

May dissolve in DMSO (in most cases), if not, try other solvents such as H2O, Ethanol, or DMF with a minute amount of products to avoid loss of samples

Note: Listed below are some common formulations that may be used to formulate products with low water solubility (e.g. < 1 mg/mL), you may test these formulations using a minute amount of products to avoid loss of samples.

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Injection Formulation 1: DMSO : Tween 80： Saline = 10 : 5 : 85 (i.e. 100 μL DMSO stock solution → 50 μL Tween 80 → 850 μL Saline)
*Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH ₂ O to obtain a clear solution.
Injection Formulation 2: DMSO : PEG300 ：Tween 80 : Saline = 10 : 40 : 5 : 45 (i.e. 100 μL DMSO → 400 μLPEG300 → 50 μL Tween 80 → 450 μL Saline)
Injection Formulation 3: DMSO : Corn oil = 10 : 90 (i.e. 100 μL DMSO → 900 μL Corn oil)
Example: Take the Injection Formulation 3 (DMSO : Corn oil = 10 : 90) as an example, if 1 mL of 2.5 mg/mL working solution is to be prepared, you can take 100 μL 25 mg/mL DMSO stock solution and add to 900 μL corn oil, mix well to obtain a clear or suspension solution (2.5 mg/mL, ready for use in animals).

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Injection Formulation 4: DMSO : 20% SBE-β-CD in saline = 10 : 90 [i.e. 100 μL DMSO → 900 μL (20% SBE-β-CD in saline)]
*Preparation of 20% SBE-β-CD in Saline (4°C，1 week): Dissolve 2 g SBE-β-CD in 10 mL saline to obtain a clear solution.
Injection Formulation 5: 2-Hydroxypropyl-β-cyclodextrin : Saline = 50 : 50 (i.e. 500 μL 2-Hydroxypropyl-β-cyclodextrin → 500 μL Saline)
Injection Formulation 6: DMSO : PEG300 : castor oil : Saline = 5 : 10 : 20 : 65 (i.e. 50 μL DMSO → 100 μLPEG300 → 200 μL castor oil → 650 μL Saline)
Injection Formulation 7: Ethanol : Cremophor : Saline = 10： 10 : 80 (i.e. 100 μL Ethanol → 100 μL Cremophor → 800 μL Saline)
Injection Formulation 8: Dissolve in Cremophor/Ethanol (50 : 50), then diluted by Saline
Injection Formulation 9: EtOH : Corn oil = 10 : 90 (i.e. 100 μL EtOH → 900 μL Corn oil)
Injection Formulation 10: EtOH : PEG300：Tween 80 : Saline = 10 : 40 : 5 : 45 (i.e. 100 μL EtOH → 400 μLPEG300 → 50 μL Tween 80 → 450 μL Saline)

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Oral Formulation 1: Suspend in 0.5% CMC Na (carboxymethylcellulose sodium)
Oral Formulation 2: Suspend in 0.5% Carboxymethyl cellulose
Example: Take the Oral Formulation 1 (Suspend in 0.5% CMC Na) as an example, if 100 mL of 2.5 mg/mL working solution is to be prepared, you can first prepare 0.5% CMC Na solution by measuring 0.5 g CMC Na and dissolve it in 100 mL ddH2O to obtain a clear solution; then add 250 mg of the product to 100 mL 0.5% CMC Na solution, to make the suspension solution (2.5 mg/mL, ready for use in animals).

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Oral Formulation 3: Dissolved in PEG400
Oral Formulation 4: Suspend in 0.2% Carboxymethyl cellulose
Oral Formulation 5: Dissolve in 0.25% Tween 80 and 0.5% Carboxymethyl cellulose
Oral Formulation 6: Mixing with food powders

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Note: Please be aware that the above formulations are for reference only. InvivoChem strongly recommends customers to read literature methods/protocols carefully before determining which formulation you should use for in vivo studies, as different compounds have different solubility properties and have to be formulated differently.

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 (Please use freshly prepared in vivo formulations for optimal results.)