Staphylococcus aureus is inhibited by cefapirin at doses ranging from 0.09 to 12.5 mug/mL [2]. Cephapirin, also known as cefapirin, inhibits isolates of Staphylococcus epidermidis, viridans Streptococcus, Streptococcus pyogenes, and Diplococcus pneumoniae by less than 1 μg/ml [2].

Cefapirin (200 mg; intramuscular; dairy cows) is useful for treating Staphylococcus aureus infections in dairy cows [3].

Absorption, Distribution and Excretion
... PENETRATION OF CEPHALOSPORINS INTO /CEREBROSPINAL FLUID/ IS POOR. /CEPHALOSPORINS/
CLOSE TO 50% OF CEPHAPIRIN IS BOUND TO PLASMA PROTEIN. HALF-LIFE ... IN NORMAL INDIVIDUALS IS ABOUT 40 MIN & IS DEPENDENT ON RENAL FUNCTION. SIGNIFICANT AMT ... PRESENT IN BLOOD IS REMOVED BY HEMODIALYSIS. ... EXCRETED MAINLY BY KIDNEY; ONLY 1% PRESENT IN BILE.
... /CEPHAPIRIN/ NOT ABSORBED FROM GI TRACT. IM INJECTION OF 0.5 G OF CEPHAPIRIN PRODUCES MAX PLASMA CONCN OF ABOUT 10 UG/ML @ 45 MIN; 1 G ABOUT 16 UG/ML. PLASMA CONCN ... EFFECTIVE AGAINST MANY SENSITIVE MICROORGANISMS ARE STILL DETECTABLE 6 HR AFTER SINGLE IM DOSE OF 1 G.
ABOUT 30% OF IM DOSE OF CEPHAPIRIN IS EXCRETED IN URINE IN EACH OF 1ST 2 HR PERIODS AFTER INJECTION.
For more Absorption, Distribution and Excretion (Complete) data for CEPHAPIRIN (8 total), please visit the HSDB record page.

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Metabolism / Metabolites
Major metabolite detected is desacetylcephapirin.
MAJOR METABOLITE OF CEPHAPIRIN IS DEACETYLCEPHAPIRIN, WHICH IS ABOUT ONE HALF OF ANTIMICROBIAL ACTIVITY OF PARENT CMPD; 20% OF ANTIBIOTIC ACTIVITY IN PLASMA IS DUE TO DEACETYLATED CMPD.
Cephapirin is partially metabolized in the plasma, liver and kidneys to diacetyl cephapirin, which has about 50% of the antibacterial activity of the parent cmpd. ... Up to 20% of the antibiotic activity in serum is due to the desacetyl metabolite.

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Biological Half-Life
EIGHT HEALTHY ADULTS RECEIVED 1 G, IV AND IM. BIOLOGICAL HALF-LIFE OF CEPHAPIRIN WAS 43 MIN. ABSORPTION HALF-LIFE OF CEPHAPIRIN FROM IM ADMIN WAS 1.25 HR.
IV SODIUM CEPHAPIRIN SHOWED BIEXPONENTIAL DISPOSITION CHARACTERISTICS IN SERUM & SUBCHONDRAL BONE, REACHING DISTRIBUTION EQUIL WITHIN 20 MIN. RAPIDLY ELIMINATED, WITH BETA HALF-LIFE OF ABOUT 0.3 HR & BODY CLEARANCE OF 400 ML/MIN.
Serum half-life is 0.6 hr /From table/

Interactions
PROBENECID & SULFINPYRAZONE COMPETE WITH URIC ACID @ RENAL TUBULE TRANSPORT SITES. URINARY EXCRETION OF OTHER WEAK ACIDS ALSO CAN BE AFFECTED BY THESE URICOSURIC AGENTS. ... CEPHALOSPORINS ... MAY BE AFFECTED BY CONCURRENT USE OF PROBENECID OR SULFINPYRAZONE. /CEPHALOSPORINS/
The admixture of beta-lactam antibacterials (penicillins and cephalosporins) and aminoglycosides may result in substantial mutual inactivation. If they are administered concurrently, they should be administered in separate sites. Do not mix them in the same intravenous bag or bottle. /Cephalosporins/

[1]. Bran JL, et al. Clinical and in vitro evaluation of cephapirin, a new cephalosporin antibiotic. Antimicrob Agents Chemother. 1972 Jan;1(1):35-40.
[2]. Axelrod J, et, al. Cephapirin: in vitro antibacterial spectrum. Appl Microbiol. 1971 Nov;22(5):904-8.
[3]. Roy JP, et, al. Efficacy of a 5-day extended therapy program during lactation with cephapirin sodium in dairy cows chronically infected with Staphylococcus aureus. Can Vet J. 2009 Dec;50(12):1257-62.

Cephapirin is a cephalosporin with acetoxymethyl and 2(pyridin-4-ylsulfanyl)acetamido substituents at positions 3 and 7, respectively, of the cephem skeleton. It is used (as its sodium salt) as an antibiotic, being effective against gram-negative and gram-positive organisms. It has a role as an antibacterial drug. It is a conjugate acid of a cephapirin(1-).
Cefapirin (INN, also spelled cephapirin), commonly marketed under the trade name Cefadyl, is a first-generation cephalosporin antibiotic that is available in injectable formulations. Production for use in humans has been discontinued in the United States. Cefapirin is partly plasma-bound and is effective against gram-negative and gram-positive organisms.
Cephapirin has been reported in Apis cerana with data available.
Cephapirin is a semisynthetic, broad-spectrum, first-generation cephalosporin with antibacterial activity. Cephapirin binds to and inactivates penicillin-binding proteins (PBPs) located on the inner membrane of the bacterial cell wall. PBPs are enzymes involved in the terminal stages of assembling the bacterial cell wall and in reshaping the cell wall during growth and division. Inactivation of PBPs interferes with the cross-linkage of peptidoglycan chains necessary for bacterial cell wall strength and rigidity. This results in the weakening of the bacterial cell wall and causes cell lysis.
Cephalosporin antibiotic, partly plasma-bound, that is effective against gram-negative and gram-positive organisms.
See also: Cephapirin Sodium (has salt form); Cephapirin Benzathine (active moiety of).

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Drug Indication
For treatment of infections caused by susceptible bacteria.

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Mechanism of Action
The bactericidal activity of cephapirin results from the inhibition of cell wall synthesis via affinity for penicillin-binding proteins (PBPs).
... VERY RESISTANT TO ACTION OF PENICILLINASE, FOR WHICH IT IS BOTH COMPETITIVE & NONCOMPETITIVE INHIBITOR ... IT DOES NOT SUPPRESS BREAKDOWN OF PENICILLIN G BY STAPHYLOCOCCAL PENICILLINASE. CEPHALOSPORIN C & ITS SEMISYNTHETIC CONGENERS INDUCE SYNTH OF PENICILLINASE BY B CEREUS & STAPH AUREUS. /CEPHALOSPORIN C/
... ENZYME ACTING SPECIFICALLY ON CEPHALOSPORIN C TO DESTROY ITS ANTIBACTERIAL ACTIVITY. THIS SUBSTANCE, CEPHALOSPORINASE IS ALSO BETA-LACTAMASE. MOST PREPN OF ENZYME ALSO EXHIBIT PENICILLINASE ACTIVITY, & SOME MICROORGANISMS PRODUCE ONE BETA-LACTAMASE THAT ACTS ON BOTH PENICILLIN & CEPHALOSPORINS. /CEPHALOSPORIN C/
Bactericidal; action depends on ability to reach and bind pencillin-binding proteins located in bacterial cytoplasmic membranes; cephalosporins inhibit bacterial septum and cell wall synthesis, probably by acylation of membrane-bound transpeptidase enzymes. This prevents cross-linkage of peptidoglycan chains, which is necessary for bacterial cell wall strength and rigidity. Also, cell division and growth are inhibited, and lysis and elongation of susceptible bacteria frequently occur. Rapidly dividing bacteria are those most susceptible to the action of cephalosporins. /Cephalosporins/

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Therapeutic Uses
Cephalosporins
Cephalosporins are still useful as alternatives to penicillins for a variety of infections in patients who can't tolerate penicillins. These include streptococcal and staphylococcal infections.
BACTERIA SUSCEPTIBLE TO CEPHALOTHIN /BOTH GRAM POSITIVE & GRAM-NEGATIVE MICROORGANISMS/ ARE SENSITIVE OVER APPROX SAME RANGE OF CONCN TO ... CEPHAPIRIN. ... CEPHAPIRIN IS SOMEWHAT MORE INHIBITORY THAN CEPHALOTHIN FOR GROUP-A STREP PYOGENES & PNEUMOCOCCUS.
CEPHAPIRIN IS ONE OF NEWEST SEMISYNTHETIC CEPHALOSPORINS. ... LIKE OTHER CEPHALOSPORINS, CEPHAPIRIN SHOULD BE RESERVED FOR THOSE INSTANCES IN WHICH ORGANISM IS SENSITIVE TO IT & PATIENT IS HYPERSENSITIVE TO PENICILLIN.
For more Therapeutic Uses (Complete) data for CEPHAPIRIN (10 total), please visit the HSDB record page.

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Drug Warnings
SINCE ... CEPHAPIRIN ... ADMIN AS ... SODIUM SALTS, CARE SHOULD BE EXERCISED IN USE OF LARGE DOSES IN PERSONS WITH IMPAIRED CAPACITY TO EXCRETE THIS CATION. ... SUPRAINFECTIONS, USUALLY DUE TO GRAM NEGATIVE BACTERIA, MAY OCCUR WHEN THESE ANTIBIOTICS ARE EMPLOYED.
TYPICAL DOSAGE SCHEDULES ... FOR MOST OF CEPHALOSPORINS MUST BE MODIFIED FOR PATIENTS WITH IMPAIRED RENAL FUNCTION. /CEPHALOSPORINS/
... HYPERSENSITIVITY REACTIONS TO CEPHALOSPORINS IS HIGHER IN PATIENTS WHO HAVE SHOWN ALLERGIC MANIFESTATIONS FOLLOWING ADMIN OF PENICILLIN. THIS APPEARS TO BE RELATED TO SENSITIZATION TO BETA-LACTAM RING COMMON TO BOTH THESE DRUGS. /CEPHALOSPORINS/
... ENTEROCOCCAL ENDOCARDITIS CANNOT BE CURED WITH CEPHALOSPORIN EVEN WHEN ... GIVEN CONCURRENTLY WITH GENTAMICIN OR STREPTOMYCIN. ... ENTEROBACTER (AEROBACTER) INFECTIONS ARE, AS A RULE, RESISTANT TO THESE CMPD. /CEPHALOSPORINS/
For more Drug Warnings (Complete) data for CEPHAPIRIN (10 total), please visit the HSDB record page.

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Pharmacodynamics
Cephapirin is a first-generation cephalosporin that has a wide spectrum of activity against gram-positive and gram-negative organisms. Cephapirin is more resistant to beta-lactamases than are the penicillins and so is effective against staphylococci, with the exception of methicillin-resistant staphylococci.

C17H17N3O6S2

423.458

423.056

21593-23-7

Cephapirin sodium;24356-60-3

30699

Typically exists as solid at room temperature

6.98E-26mmHg at 25°C

1.253

2

9

8

28

707

2

CC(OCC1=C(N2C([C@@H](NC(CSC3=CC=NC=C3)=O)[C@H]2SC1)=O)C(O)=O)=O

UQLLWWBDSUHNEB-CZUORRHYSA-N

InChI=1S/C17H17N3O6S2/c1-9(21)26-6-10-7-28-16-13(15(23)20(16)14(10)17(24)25)19-12(22)8-27-11-2-4-18-5-3-11/h2-5,13,16H,6-8H2,1H3,(H,19,22)(H,24,25)/t13-,16-/m1/s1

(6R,7R)-3-(acetyloxymethyl)-8-oxo-7-[(2-pyridin-4-ylsulfanylacetyl)amino]-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid

Cefapirine; Cephapirin; Cefapirin

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.)