Cephalexin dosing

Cephalexin 250-500 mg 4 times daily 25-50 mg/kg per day in 4 doses 10 days Consider in penicillin allergy (if non-type I reaction)... 

Didoxadllin 25-50 mg/kg in four divided doses Cephalexin 25-50 mg/kg in four divided doses Clindamycin 10-30 mg/kg/day in three to four divided doses0 Penicillin VK 25,000-90,000 units/kg in four divided doses Clindamycin 10-30 mg/kg in three to four doses0 Erythromycin 30-50 mg/kg in four divided doses0... 

If Keflex oral suspension contains 3 g of cephalexin in 120 mL, how many milligrams of cephalexin are contained in each teaspoonful dose ... 

Cephalosporins Have a nucleus that is similar to that of (3-lactams and similarly dismpt the synthesis of the peptidoglycan layer. This layer is important in maintaining cell wall integrity in gram-positive bacteria. Omnicef (Cefdinir) Cefzil (Cefprozil) Cephalexin (Keflex) Bioavailabihty is dose dependent is only about 16-21%. About 90% is excreted as the parent compound. It is well absorbed by the body and 90% of the dmg is excreted unchanged. 

Cephalexin (Keflex, Panixine DisperDose) [Antibiotic/ Cephalosporin-1st Generation] Uses Skin, bone, upper/lower resp tract, urinary tract Infxns Action lst-gen cephalosporin X- cell wall synth Dose Adults. 250-1000 mg PO qid Feds. 25—100 mg/kg/d PO - qid 4- in renal impair (on empty stomach) Caution [B, +] Contra Cephalosporin allergy Disp Caps, tabs, susp SE D, rash, eosinophilia, T LFTs Interactions T Nephrotox W/aminoglycosides, loop diuretics T effects W/probenecid EMS T Risk of adverse effects w/ loop diuretics monitor for signs of electrolyte disturbances and hypovolemia d/t D monitor pt for super Infxn OD May cause N/V/D, Szs, muscles spasms symptomatic and supportive... 

Both the dose normalized AUC of the plasma concentration for two hours after administration and the maximum plasma concentration exhibited nonlinearity, when cefadroxil, a (1-lactam antibiotic, was administered at different oral doses from 5 to 30 mg/kg orally (357). Coadministration of cephalexin (15 mg/kg) reduced both the AUC and C max of cephadroxil (357). Since cefadroxil and cephalexin are substrates of PEPT1 (358), this interaction may be accounted for by an interaction at the binding site of PEPT1(357). 

Cephalexin 250-500 mg orally four times dally 25-50 m kg/day divided in four doses todays... 

PeniciUinase-resistant penicillins (such as dicloxadllin) are the agents of first choice because of the increased isolation of S. aureus. First-generation cephalosporins (such as cephalexin) are also effective (see Table 47-3). Penicillin may be used for impetigo caused by S. pyogenes. It may be administered as either a single intramuscular dose of benzathine penicillin G (300,000 to 600,000 units in children, 1.2 million units in adults) or as oral penicillin VK given for 7 to 10 days. PenidUin-allergic patients can be treated with oral clindamycin. 

Dicloxacillin 25-50 m kg in tour divided doses Cephalexin 25-50 m kg in tour divided doses Clindamycin 10-30 m k day in three to tout divided doses"... 

It has been suggested that mitochondrial injury may mediate, at least in part, the nephrotoxicity of some p-lactams [67]. Mitochondrial respiration with and uptake of succinate after exposure to toxic doses of cephaloridine, cephaloglycin, or imipenem [98] showed significant reduction of both functions. Cephalexin did not affect either the mitochondrial uptake or respiration with succinate. Depressed mi-... 

The evaluation of FR 10612 (m-methanesulfonylamino cephalexin) indicated that it was comparable to cephalexin iia vitro, but more effective orally against experimental mouse infections, presumably due to entero-hepatic recirculation also leading to higher and longer blood levels.78 Although apparently dose related, human blood level curves for FR 10612 did show a longer half-life than did cephalexin. Oral cephalosporin candidate SCE-100 (tetrahydro cephalexin) has been examined extensively for in vitro and iin vivo properties.79 It is not as active as cephalexin. 

Hori R, Okumura K, Nihira H. A new dosing regimen in renal insufficiency Application to cephalexin. Clin Pharmacol Ther 1985 38 290-295. 

Although impetigo may resolve spontaneously, antimicrobial treatment is indicated to relieve symptoms, prevent formation of new lesions, and prevent complications, such as cellulitis. PeniciUinase-resistant penicillins (dicloxacUlin 12.5 mg/kg orally daily in fom divided doses for children) are preferred for treatment because of the increased incidence of infections caused by S. aureus. First-generation cephalosporins are also effective, although they are generally more expensive. Cephalexin (25-50 mg/kg orally daily in two divided doses for children) and cefadroxU (30 mg/kg oraUy daily in two divided doses for children) are used commonly. Penicillin, administered as either a single intramuscular dose of benzathine penicillin G (300,000-... 

However, none of these drugs has yet attained the star status of ampicillin, amoxycillin or cephalexin. It is also often forgotten that one of the best penicillins is the oldest one of all - penicillin G. It is unstable to acid, destroyed by beta-lactamases, but is nonetheless extremely effective (if given in large enough doses) against such rare conditions (at least in the developed world) as diphtheria, tetanus, anthrax, Lyme disease (a tick-borne disease) and venereal diseases. In addition, it usually produces few side-effects - and is thus a close approximation to a true magic bullet . 

Cefaclor is used orally. The concentration in plasma after oral administration is about 50% of that achieved after an equivalent oral dose of cephalexin. However, cefaclor is more active against H. influenzae and Moraxella catarrhalis, although some P-lactamase-producing strains of these organisms may be resistant. 

The rapid bactericidal effect of cefaclor against susceptible organisms at levels at or near the inhibitory concentrations is well documented (Sanders, 1977 Silver et al., 1977). The comparative efficacy of cefaclor, cephalexin, and ampicillin in protecting mice from lethal effects of bacterial infections intraperitoneally administered is shown in Table IX. Note a 10-fold advantage in median effective dose (ED50) for cefaclor over cephalexin against certain strains of S. pneumoniae and the activity of cefaclor against strains of H. influenzae resistant to ampicillin. 

These results closely parallel those obtained with cephalexin in similar studies. In dogs, cefaclor is more labile to metabolism. Only a minor fraction of the administered dose is eliminated unchanged by the kidney. Total radiocarbon levels in both blood and urine were at considerably higher levels than could be present in unchanged antibiotic. As in the other species, biliary excretion in the dog plays only a minor role in the elimination of parent antibiotic and its metabolites (Sullivan et al., 1976). Other studies in the dog also showed rapid absorption of cefaclor following oral and intramuscular administration. Most of the dose was renally excreted, about 50% as intact antibiotic and the other 50% as microbiologically inactive degradation products. In the dog, cefaclor was shown to concentrate in the kidney and liver and to penetrate at lower levels into hard bone and synovial fluid (Quay et al., 1976). 

A study in mice showed that orally dosed cefaclor was rapidly absorbed with an efficiency that approached 100% based on a comparison of urinary excretion after oral and parenteral dosage. Blood level curves following oral and parenteral administration supported this conclusion. In addition, cefaclor disappeared from the gastrointestinal tract and appeared in the urine at rates similar to those of cephalexin, a cephalosporin known to be well absorbed orally (W. E. Wright, private communication). 

Although only 60% of the administered dose was recovered in the urine of rats (compared to >77% with cephalexin), urinary recovery in dogs was equivalent for both FR10612 and cephalexin (—45-50%). Urinary recovery in monkeys was especially poor for both FR10612 (18%) and cephalexin (3.4%). The urinary recovery of FR10612 after oral administration to humans was 88.6%, whereas that of cephalexin was 87.1%. No evidence of any active metabolites in the urine of any of the species examined or in the bile from rats was found. 

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