Description
Cefadroxil has an amoxicillin-like side chain at C-7 and is orally active. There are some indications that
cefadroxil has some immunostimulant properties mediated through T-cell activation and that this is of
material assistance to patients in fighting infections. The prolonged biological half-life of cefadroxil allows
once-a-day dosage.
Chemical Properties
White Crystalline Solid. Soluble in chloroform, miscible with ethanol and ether, insoluble in water, and will change color when exposed to light or for a long time.
Uses
Cefadroxil Monohydrate is a semi-synthetic cephalosporin antibacterial. It has been used for various community-acquired infections for which oral cephalosporins are appropriate.
Definition
ChEBI: The hydrate that is the monohydrate of the cephalosporin cefadroxil.
brand name
Duricef (Bristol-Myers Squibb);
Ultracef (Bristol Labs).
Antimicrobial activity
Resembles closely that of cefalexin
General Description
Cefadroxil is a semisynthetic first-generation β-lactam cephalosporin antibiotic derived from cefalexin with antibacterial activity. It is used to treat urinary tract infections, skin and skin structure infections, pharyngitis, and tonsillitis caused by susceptible bacteria.
Application
Cefadroxil was found by Bristol-Myers Co. in 1976. A hydroxyl group was attached to the benzene ring of cephalexin. Like amoxicillin and ampicillin, cefadroxil shows almost the same antibacterial activity spectrum as cephalexin and superior oral absorption. Its in vivo activity is four to six times greater than that of cephalexin, and its half-life in serum is twice as long.
Pharmacokinetics
Oral absorption: >90%
C
max 250 mg oral: c. 9 mg/L after 1.2 h
500 mg oral: c. 18 mg/L after 1.2 h
Plasma half-life: 1–1.5 h
Plasma protein binding : 20%
Absorption is little affected by administration with food.
Distribution is similar to that of cefalexin. It is eliminated
unchanged by glomerular filtration and tubular secretion;
90% of the dose appears in the urine over 24 h, most in the
first 6 h, producing concentrations exceeding 500 mg/L.
Pharmacology
Cefadroxil has a broad spectrum of antimicrobial action; it is active with respect to Grampositive and Gram-negative microorganisms. Like all of the other drugs described above,
it acts as a bactericide by disrupting the process of restoring the membranes of bacteria.
Synonyms of this drug are bidocef, cefadril, duracef, ultracef, and others.
Clinical Use
Cefadroxil (Duricef) is an orally active semisyntheticderivative of 7-ADCA, in which the 7-acyl group is the Dhydroxylphenylglycylmoiety. This compound is absorbedwell after oral administration to give plasma levels that reach75% to 80% of those of an equal dose of its close structuralanalog cephalexin. The main advantage claimed for cefadroxilis its somewhat prolonged duration of action, whichpermits once-a-day dosing. The prolonged duration of actionof this compound is related to relatively slow urinary excretionof the drug compared with other cephalosporins, butthe basis for this remains to be explained completely. Theantibacterial spectrum of action and therapeutic indications ofcefadroxil are very similar to those of cephalexin and cephradine.The D-p-hydroxyphenylglycyl isomer is much moreactive than the L-isomer.
Side effects
Side effects described are those common to oral cephalosporins.
Synthesis
Cefadroxil, [6R-[6|á,7|?(R)]]-3-methyl-8-oxo-7-[[amino(4-hydroxyphenyl)
acetyl]amino]-5-thia-1-azabicyclo[4.2.0]oct-2-en-2-carboxylic acid (32.1.2.14), is an analog of cephalexin and differs only in the presence of a hydroxyl group in the fourth position of the phenyl ring of phenylglycine, and is synthesized by a scheme analogous to the
scheme of cephradin synthesis.
Veterinary Drugs and Treatments
Cefadroxil is approved for oral therapy in treating susceptible infections
of the skin, soft tissue, and genitourinary tract in dogs and cats.
The veterinary oral tablets have been discontinued (in the USA), but
human-labeled oral capsules and tablets are still available.
in vitro
the inhibitory activity of this compound was similar to that of cephalexin and cephradine when tested against 602 clinical isolates on mueller-hinton medium. in the oral treatment of experimental infections of mice, cefadroxil was more effective than cephalexin against streptococcus pyogenes, and comparably effective against streptococcus pneumoniae, staphylococcus aureus, and several gram-negative species [1].
in vivo
in mice, oral administration of cefadroxil at doses ranging from 25 to 100 mg/kg attained peak concentrations in the blood. higher peak levels were noted with cefadroxil than with cephalexin at a dose of 200 mg/kg [1].
Drug interactions
Potentially hazardous interactions with other drugs
Anticoagulants: effects of coumarins may be
enhanced.
Metabolism
More than 90% of a dose of cefadroxil may be excreted
unchanged in the urine within 24 hours by glomerular
filtration and tubular secretion.
References
[1] buck r e, price k e. cefadroxil, a new broad-spectrum cephalosporin[j]. antimicrobial agents and chemotherapy, 1977, 11(2): 324-330.
[2] gerber m a, randolph m f, chanatry j, et al. once daily therapy for streptococcal pharyngitis with cefadroxil[j]. the journal of pediatrics, 1986, 109(3): 531-537.
