| Stereochemistry | ABSOLUTE |
| Molecular Formula | C16H17N3O4S |
| Molecular Weight | 347.389 |
| Optical Activity | UNSPECIFIED |
| Defined Stereocenters | 3 / 3 |
| E/Z Centers | 0 |
| Charge | 0 |
SHOW SMILES / InChI
SMILES
[H][C@]12SCC(C)=C(N1C(=O)[C@H]2NC(=O)[C@H](N)C3=CC=CC=C3)C(O)=O
InChI
InChIKey=ZAIPMKNFIOOWCQ-UEKVPHQBSA-N
InChI=1S/C16H17N3O4S/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)/t10-,11-,15-/m1/s1
| Molecular Formula | C16H17N3O4S |
| Molecular Weight | 347.389 |
| Charge | 0 |
| Count |
MOL RATIO
1 MOL RATIO (average) |
| Stereochemistry | ABSOLUTE |
| Additional Stereochemistry | No |
| Defined Stereocenters | 3 / 3 |
| E/Z Centers | 0 |
| Optical Activity | UNSPECIFIED |
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
Doses
AEs
Sourcing
Sample Use Guides
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
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.
