CEPHALEXIN

First approved in 1971

Details

Stereochemistry	ABSOLUTE
Molecular Formula	C16H17N3O4S.H2O
Molecular Weight	365.404
Optical Activity	UNSPECIFIED
Defined Stereocenters	3 / 3
E/Z Centers	0
Charge	0

SHOW SMILES / InChI

Structure Search

SMILES

O.CC1=C(N2[C@H](SC1)[C@H](NC(=O)[C@H](N)C3=CC=CC=C3)C2=O)C(O)=O

InChI

InChIKey=AVGYWQBCYZHHPN-CYJZLJNKSA-N

InChI=1S/C16H17N3O4S.H2O/c1-8-7-24-15-11(14(21)19(15)12(8)16(22)23)18-13(20)10(17)9-5-3-2-4-6-9;/h2-6,10-11,15H,7,17H2,1H3,(H,18,20)(H,22,23);1H2/t10-,11-,15-;/m1./s1

HIDE SMILES / InChI

Molecular Formula	H2O
Molecular Weight	18.0153
Charge	0
Count

Stereochemistry	ACHIRAL
Additional Stereochemistry	No
Defined Stereocenters	0 / 0
E/Z Centers	0
Optical Activity	NONE

Molecular Formula	C16H17N3O4S
Molecular Weight	347.389
Charge	0
Count

Stereochemistry	ABSOLUTE
Additional Stereochemistry	No
Defined Stereocenters	3 / 3
E/Z Centers	0
Optical Activity	UNSPECIFIED

Description
Sources: https://www.accessdata.fda.gov/drugsatfda_docs/label/2006/050405s097lbl.pdf

Cephalexin is a semisynthetic cephalosporin antibiotic intended for oral administration. In vitro tests demonstrate that the cephalosporins are bactericidal because of their inhibition of cell-wall synthesis. Cephalexin has been shown to be active against most strains of the following microorganisms both in vitro: Staphylococcus aureus (including penicillinase-producing strains), Streptococcus pneumoniae (penicillin-susceptible strains), Streptococcus pyogenes, Escherichia coli, Haemophilus influenzae, Klebsiella pneumoniae, Moraxella (Branhamella) catarrhalis, Proteus mirabilis. Cephalexin is indicated for the treatment of the respiratory tract, skin and skin structure, bone and genitourinary tract infections when caused by susceptible strains of the designated microorganisms.

CNS Activity

Originator

Approval Year

Targets

Primary Target	Pharmacology	Condition	Potency
Bacterial penicillin-binding protein 234 Target ID: CHEMBL2354204 Sources: https://www.ncbi.nlm.nih.gov/pubmed/7447421	Inhibitor 8504

Conditions

Condition	Modality	Targets	Highest Phase	Product
Bacterial Infections 63 Sources: https://www.accessdata.fda.gov/drugsatfda_docs/label/2006/050405s097lbl.pdf	Curative		Approved 8583	KEFLEX Approved Use Cephalexin capsules are indicated for the treatment of the following infections when caused by susceptible strains of the designated microorganisms: Respiratory tract infections caused by Streptococcus pneumoniae and Streptococcus pyogenes (Penicillin is the usual drug of choice in the treatment and prevention of streptococcal infections, including the prophylaxis of rheumatic fever. Cephalexin capsules are generally effective in the eradication of streptococci from the nasopharynx; however, substantial data establishing the efficacy of cephalexin capsules in the subsequent prevention of rheumatic fever are not available at present.) Otitis media due to Streptococcus pneumoniae, Haemophilus influenzae, Staphylococcus aureus, Streptococcus pyogenes , and Moraxella catarrhalis Skin and skin structure infections caused by Staphylococcus aureus and/or Streptococcus pyogenes Bone infections caused by Staphylococcus aureus and/or Proteus mirabilis Genitourinary tract infections, including acute prostatitis, caused by Escherichia coli, Proteus mirabilis, and Klebsiella pneumoniae Note — Culture and susceptibility tests should be initiated prior to and during therapy. Renal function studies should be performed when indicated. To reduce the development of drug-resistant bacteria and maintain the effectiveness of cephalexin and other antibacterial drugs, cephalexin 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. Launch Date 1971

C_max

Value	Dose	Co-administered	Analyte	Population
18.25 μg/mL EXPERIMENT https://pubmed.ncbi.nlm.nih.gov/23688276/	500 mg single, oral dose: 500 mg route of administration: Oral experiment type: SINGLE co-administered:		CEPHALEXIN plasma	Homo sapiens population: HEALTHY age: ADULT sex: MALE food status: FASTED
126 mg/L EXPERIMENT https://pubmed.ncbi.nlm.nih.gov/23811740	40 mg/kg 3 times / day multiple, oral dose: 40 mg/kg route of administration: Oral experiment type: MULTIPLE co-administered:		CEPHALEXIN plasma	Homo sapiens population: UNHEALTHY age: CHILD sex: UNKNOWN food status: UNKNOWN

AUC

Value	Dose	Co-administered	Analyte	Population
31.22 μg × h/mL EXPERIMENT https://pubmed.ncbi.nlm.nih.gov/23688276/	500 mg single, oral dose: 500 mg route of administration: Oral experiment type: SINGLE co-administered:		CEPHALEXIN plasma	Homo sapiens population: HEALTHY age: ADULT sex: MALE food status: FASTED
245 mg × h/L EXPERIMENT https://pubmed.ncbi.nlm.nih.gov/23811740	40 mg/kg 3 times / day multiple, oral dose: 40 mg/kg route of administration: Oral experiment type: MULTIPLE co-administered:		CEPHALEXIN plasma	Homo sapiens population: UNHEALTHY age: CHILD sex: UNKNOWN food status: UNKNOWN

T_1/2

Value	Dose	Co-administered	Analyte	Population
1.12 h EXPERIMENT https://pubmed.ncbi.nlm.nih.gov/23688276/	500 mg single, oral dose: 500 mg route of administration: Oral experiment type: SINGLE co-administered:		CEPHALEXIN plasma	Homo sapiens population: HEALTHY age: ADULT sex: MALE food status: FASTED

F_unbound

Value	Dose	Co-administered	Analyte	Population
85% EXPERIMENT https://pubmed.ncbi.nlm.nih.gov/23688276/	500 mg single, oral dose: 500 mg route of administration: Oral experiment type: SINGLE co-administered:		CEPHALEXIN plasma	Homo sapiens population: HEALTHY age: ADULT sex: MALE food status: FASTED

Doses

Dose	Population	Adverse events
40 mg/kg 3 times / day multiple, oral Dose: 40 mg/kg, 3 times / day Route: oral Route: multiple Dose: 40 mg/kg, 3 times / day Sources: https://pubmed.ncbi.nlm.nih.gov/23811740	unhealthy, 1-16 years Health Status: unhealthy Age Group: 1-16 years Sex: M+F Sources: https://pubmed.ncbi.nlm.nih.gov/23811740	Disc. AE: Neutropenia... AEs leading to discontinuation/dose reduction: Neutropenia (1 patient) Sources: https://pubmed.ncbi.nlm.nih.gov/23811740
500 mg 2 times / day multiple, oral Dose: 500 mg, 2 times / day Route: oral Route: multiple Dose: 500 mg, 2 times / day Sources: https://pubmed.ncbi.nlm.nih.gov/30915263	unhealthy, 90 years Health Status: unhealthy Age Group: 90 years Sex: F Sources: https://pubmed.ncbi.nlm.nih.gov/30915263	Disc. AE: Tendonitis... AEs leading to discontinuation/dose reduction: Tendonitis (1 patient) Sources: https://pubmed.ncbi.nlm.nih.gov/30915263

AEs

AE	Significance	Dose	Population
Neutropenia	1 patient Disc. AE	40 mg/kg 3 times / day multiple, oral Dose: 40 mg/kg, 3 times / day Route: oral Route: multiple Dose: 40 mg/kg, 3 times / day Sources: https://pubmed.ncbi.nlm.nih.gov/23811740	unhealthy, 1-16 years Health Status: unhealthy Age Group: 1-16 years Sex: M+F Sources: https://pubmed.ncbi.nlm.nih.gov/23811740
Tendonitis	1 patient Disc. AE	500 mg 2 times / day multiple, oral Dose: 500 mg, 2 times / day Route: oral Route: multiple Dose: 500 mg, 2 times / day Sources: https://pubmed.ncbi.nlm.nih.gov/30915263	unhealthy, 90 years Health Status: unhealthy Age Group: 90 years Sex: F Sources: https://pubmed.ncbi.nlm.nih.gov/30915263

Overview

CYP3A4	CYP2C9	CYP2D6	hERG

OverviewOther

Other Inhibitor	Other Substrate	Other Inducer
	CYP 303 PEPT1 60 PEPT2 37

Drug as victim

Target	Modality	Activity
CYP 303	substrate 4014 Sources: https://www.jstage.jst.go.jp/article/antibiotics1968/22/5/22_5_195/_article/-char/en	no
PEPT1 60	substrate 4014 Sources: https://www.jstage.jst.go.jp/article/bpb/29/1/29_1_90/_article/-char/ja/	yes
PEPT2 37	substrate 4014 Sources: https://link.springer.com/article/10.1007/s00228-008-0488-4	yes

Sourcing

Vendor/Aggregator	ID	URL
3B Scientific (Wuhan) Corp	3B1-01401	http://www.3bsc.com/index/pro_info.php?id=21613
3B Scientific (Wuhan) Corp	3B2-0058	http://www.3bsc.com/index/pro_info.php?id=19414
AA Blocks	AA0037NO	https://www.aablocks.com/goods/Goods/detail?id=AA0037NO
Aaron Chemicals	AR0038FG	http://www.aaronchem.com/15686-71-2
AbMole Bioscience	M4900	http://www.abmole.com/products/cephalexin.html
Achemtek	0104-058165	http://www.achemtek.com/15686-71-2
AHH Chemical co.,ltd	API-1053	http://www.ahhchemical.com/product/API-1053.html
AK Scientific, Inc. (AKSCI)	2312AH	http://www.aksci.com/item_detail.php?cat=2312AH
Alfa Chemistry	AP15686712	https://reagents.alfa-chemistry.com/product/cefalexin-cas-15686-71-2-5788.html
ApexBio Technology	B1692	http://www.apexbt.com/cephalexin.html
Aurora Fine Chemicals LLC	A17.908.211	http://online.aurorafinechemicals.com/info?ID=A17.908.211
Aurora Fine Chemicals LLC	K14.726.335	http://online.aurorafinechemicals.com/info?ID=K14.726.335
BioCrick	BCC4646	http://www.biocrick.com/Cephalexin-BCC4646.html
BioSynth	C-2660	https://www.biosynth.com/products/biochemistry/culture-media-additives/products/C-2660.html
BioSynth	Q-200819	https://www.biosynth.com/en/products/life-science/culture-media-additives/products/Q-200819.html
BLD Pharm	BD120242	http://www.bldpharm.com/products/15686-71-2.html
Chem Scene	CS-2137	http://www.chemscene.com/15686-71-2.html
ChemMol	49411600	http://www.chemmol.com/chemmol/49411600.html
Chemspace	CSSB00020617717	https://chem-space.com/CSSB00020617717
Clearsynth	CS-O-30876	https://www.clearsynth.com/en/CSO30876.html
CSNpharm	CSN10562	https://www.csnpharm.com/products/cephalexin.html
eNovation Chemicals	D673807	https://www.enovationchem.com/ProductDetails.asp?ProductID=D673807
Glentham Life Sciences	GA1648	http://www.glentham.com/products/product/GA1648/
iChemical	EBD56457	http://www.ichemical.com/products/15686-71-2.html?utm_source=PubChem&utm_medium=website&utm_campaign=product%20catalogs
Lab Network	LN00003630	https://labnetwork.com/frontend-app/p/#!/moleculedetails/LN00003630
MedChem Express	HY-B0200	https://www.medchemexpress.com/Cephalexin.html
MuseChem	A001152	https://www.musechem.com/product/A001152.html
Selleck Chemicals	S1502	http://www.selleckchem.com/products/Cephalexin-(Cefalexin).html
Sigma-Aldrich	33989_SIAL	https://www.sigmaaldrich.com/catalog/product/sial/33989?utm_source=pubchem&utm_campaign=pubchem_2017&utm_medium=referral
Sigma-Aldrich	BP061_SIAL	https://www.sigmaaldrich.com/catalog/product/sial/bp061?utm_source=pubchem&utm_campaign=pubchem_2017&utm_medium=referral
Sigma-Aldrich	PHR1848_SIAL	https://www.sigmaaldrich.com/catalog/product/sial/phr1848?utm_source=pubchem&utm_campaign=pubchem_2017&utm_medium=referral
Sinfoo Biotech	S061061	http://www.sinfoobiotech.com/product/1064464

PubMed

Title	Date	PubMed
Solid state 'adsorption' of fine antibiotic powders onto sorbitol: effects of particle size, state of sorbed water and surface free energy characteristics.	2002-12	12453612
Orbital abscess following uncomplicated phacoemulsification cataract surgery.	2002-12	12427235
Risk of serious skin disorders among users of oral antifungals: a population-based study.	2002-11-28	12456265
Modelling of the enzymatic kinetically controlled synthesis of cephalexin: influence of diffusion limitation.	2002-11-05	12226866
In vitro and in situ evidence for the contribution of Labrasol and Gelucire 44/14 on transport of cephalexin and cefoperazone by rat intestine.	2002-11	12445561
Influence of a new prophylactic antibiotic therapy on the incidence of liver abscesses after chemoembolization treatment of liver tumors.	2002-11	12427817
Integrated reactor concepts for the enzymatic kinetic synthesis of cephalexin.	2002-10-20	12209770
Enzyme reaction engineering: effect of methanol on the synthesis of antibiotics catalyzed by immobilized penicillin G acylase under isothermal and non-isothermal conditions.	2002-10-05	12363348
In vitro permeation of beta-lactam antibiotics across rat jejunum and its correlation with oral bioavailability in humans.	2002-10	12392595
Quantitative characterization of the nucleophile reactivity in penicillin acylase-catalyzed acyl transfer reactions.	2002-09-23	12479414
Frequency of isolation and antimicrobial susceptibility patterns of Staphylococcus intermedius and Pseudomonas aeruginosa isolates from canine skin and ear samples over a 6-year period (1992-1997).	2002-09-11	12220023
An indirect conductimetric screening method for the detection of antibiotic residues in bovine kidneys.	2002-09	12375852
Uptake of cyclic dipeptide by PEPT1 in Caco-2 cells: phenolic hydroxyl group of substrate enhances affinity for PEPT1.	2002-09	12356285
Selective antibiotic use to prevent postoperative wound infection after external dacryocystorhinostomy.	2002-09	12352818
Private pharmacies in Hanoi, Vietnam: a randomized trial of a 2-year multi-component intervention on knowledge and stated practice regarding ARI, STD and antibiotic/steroid requests.	2002-09	12225513
Shorter courses of parenteral antibiotic therapy do not appear to influence response rates for children with acute hematogenous osteomyelitis: a systematic review.	2002-08-14	12181082
[Use of antibiotics in general practice and at the Clinic for Infectious Diseases].	2002-08-13	12170869
[Bacteriologic examination of gallbladder contents].	2002-08-13	12170867
A two-step, one-pot enzymatic synthesis of cephalexin from D-phenylglycine nitrile.	2002-08-05	12115424
Advantages of using non-isothermal bioreactors for the enzymatic synthesis of antibiotics: the penicillin G acylase as enzyme model.	2002-08-05	12115422
Prophylactic antibiotics in cirrhotics with upper gastrointestinal hemorrhage: a prospective, controlled trial.	2002-08	12455806
Localized lymphatic sporotrichosis after fish-induced injury (Tilapia sp.).	2002-08	12230224
Infantile pertussis rediscovered in China.	2002-08	12141975
Immunoglobulin E binding determinants on beta-lactam drugs.	2002-08	12130943
Determination of transport in the Caco-2 cell assay of compounds varying in lipophilicity using LC-MS: enhanced transport of Leu-enkephalin analogues.	2002-08	12128164
Comparison of several methods used for the determination of cephalosporins. Analysis of cephalexin in pharmaceutical samples.	2002-07-01	12062642
Outcome of percutaneous nephrostomy for the management of pyonephrosis.	2002-07	12376218
Pharmacokinetics of cephalexin in the horse after intravenous and intramuscular administration of two formulations.	2002-07	12359489
Update on prosthetic joints, dental treatment, and antibiotic prophylaxis.	2002-07	12242835
Staphylococcus aureus: colonizing features and influence of an antibacterial treatment in adults with atopic dermatitis.	2002-07	12100185
Antibacterial activity of oral antibiotics against community-acquired respiratory pathogens from three European countries.	2002-07	12077154
Sensitivity and resistance of antibiotics in common infection of male and female.	2002-06-05	12043324
Susceptibility change to antibiotics of Staphylococcus aureus strains isolated from skin infections between July 1994 and November 2000.	2002-06	12111576
Typhoidal focal suppurative lymphatic abscess.	2002-06	12070955
Community-acquired methicillin-resistant Staphylococcus aureus, Finland.	2002-06	12023917
Bacterial colonization of intravenous catheters in young dogs suspected to have parvoviral enteritis.	2002-05-01	11991409
Evaluation of UV-radiation induced singlet oxygen generation potential of selected drugs.	2002-05	12024804
Cefdinir: an advanced-generation, broad-spectrum oral cephalosporin.	2002-04	12017394
Salmonella mastitis in a child.	2002-04	11999687
The effect of tablet formulation and hardness on in vitro release of cephalexin from Eudragit L100 based extended release tablets.	2002-04	11995942
The role of hydrophobic active-site residues in substrate specificity and acyl transfer activity of penicillin acylase.	2002-04	11985586
Febrile urinary tract infection: Escherichia coli susceptibility to oral antimicrobials.	2002-03	11956854
Antibiotic prophylaxis in infants and young children with cystic fibrosis: a randomized controlled trial.	2002-03	11953726
Emergence of new pathogens in CF: the devil we know or the devil we don't know?	2002-03	11953721
Enrofloxacin resistance in Escherichia coli isolated from dogs with urinary tract infections.	2002-01-15	12126128
Effect of cephalexin on the pharmacokinetics of metformin in healthy human volunteers.	2002	12222753
Determination of cephalexin in oral suspensions by micellar electrokinetic chromatography.	2002	12212913
[Effect of peptide antibacterial factor and changes in Staphylococcus susceptibility to antibiotics].	2002	12087717
Skin and soft tissue infection.	2001-07	11980459
Cephalexin-related nephropathy.	1975-11-10	1242194

Patents

Sample Use Guides

In Vivo Use Guide

Adults — The adult dosage ranges from 1 to 4 g daily in divided doses. The usual adult dose is 250 mg every 6 hours. For the following infections, a dosage of 500 mg may be administered every 12 hours: streptococcal pharyngitis, skin and skin structure infections, and uncomplicated cystitis in patients over 15 years of age. Cystitis therapy should be continued for 7 to 14 days. For more severe infections or those caused by less susceptible organisms, larger doses may be needed. If daily doses of Keflex greater than 4 g are required, parenteral cephalosporins, in appropriate doses, should be considered. Pediatric Patients — The usual recommended daily dosage for pediatric patients is 25 to 50 mg/kg in divided doses. For streptococcal pharyngitis in patients over 1 year of age and for skin and skin structure infections, the total daily dose may be divided and administered every 12 hours. In severe infections, the dosage may be doubled. In the therapy of otitis media, clinical studies have shown that a dosage of 75 to 100 mg/kg/day in 4 divided doses is required. In the treatment of β-hemolytic streptococcal infections, a therapeutic dosage of Keflex should be administered for at least 10 days.

Route of Administration: Oral

In Vitro Use Guide

All strains of group A beta-hemolytic streptococci and Diplococcus pneumoniae were inhibited by 3.1 mug/ml. Of the Staphylococcus aureus strains, 88% were inhibited by 6.3 mug/ml, and 12.5 mug/ml was inhibitory for all S. aureus, 80% of Escherichia coli, 72% of Klebsiella-Aerobacter, and 56% of Proteus mirabilis strains. About 90 to 96% of E. coli, Klebsiella Aerobacter, and P. mirabilis strains were inhibited by 25 mug of cephalexin per ml. Pseudomonas and indole-positive Proteus strains proved to be quite resistant to cephalexin.

Substance Class	Chemical Created by `admin` on `Mon Mar 31 17:53:45 GMT 2025` Edited by `admin` on `Mon Mar 31 17:53:45 GMT 2025`
Record UNII	OBN7UDS42Y
Record Status	`Validated (UNII)`
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Name

Type

Language

CEFALEXIN MONOHYDRATE

Preferred Name

English

CEPHALEXIN

Official Name

English

66873

Code

English

7-(D-.ALPHA.-AMINO-.ALPHA.-PHENYLACETAMIDO)-3-METHYL-3-CEPHEM-4-CARBOXYLIC ACID MONOHYDRATE

Common Name

English

KEFLEX

Brand Name

English

CEPHALEXIN MONOHYDRATE [MI]

Common Name

English

CEFANEX

Brand Name

English

CEPHALEXIN MONOHYDRATE

Common Name

English

CEPHALEXIN [USP-RS]

Common Name

English

(6R,7R)-7-[(R)-2-Amino-2-phenylacetamido]-3-methyl-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid monohydrate

Systematic Name

English

CEPHALEXIN [USAN]

Common Name

English

CEFALEXIN MONOHYDRATE [EP IMPURITY]

Common Name

English

CEPHALEXIN [VANDF]

Common Name

English

NovoLexin

Brand Name

English

Cefalexin monohydrate [WHO-DD]

Common Name

English

CEFALEXIN MONOHYDRATE [EP MONOGRAPH]

Common Name

English

Biocef

Brand Name

English

CEPHALEXIN MONOHYDRATE [VANDF]

Common Name

English

KEFLET

Brand Name

English

CEPHALEXIN [USP MONOGRAPH]

Common Name

English

CEPHALEXIN [ORANGE BOOK]

Common Name

English

PANIXINE DISPERDOSE

Brand Name

English

LY-66873

Code

English

Classification Tree Code System Code

LIVERTOX

NBK548358