Concentrations of cefpodoxime in plasma and tonsillar tissue after a single oral dose of cefpodoxime proxetil

Pharmacokinetics of anti-infective agents in paediatric patients

Various differences in drug disposition exist between children and adults. For example, the volume of distribution (Vd) for many drugs is larger in children than in adults. Other parameters, including excretion and elimination may be altered in children compared with adults. The penicillins and cephalosporins are used commonly for the treatment of infection in paediatric patients. The increased Vd in children contributes to the increased elimination half-life of these agents. Clearance of the acylureido-penicillins is increased in children with cystic fibrosis, a disease that decreases the elimination half-life for these drugs. Aminoglycosides distribute into extracellular fluid and their pharmacokinetic profile is affected by changes in Vd. The Vd for aminoglycosides is slightly higher in children than in adults. Children with cystic fibrosis, burns, or cancer have higher clearance rates and larger Vd values for aminoglycosides. Few data in the literature address the pharmacokinetics of other anti-infective agents, including vancomycin, teicoplanin, erythromycin, metronidazole, chloramphenicol, and cotrimoxazole (trimethoprim-sulfamethoxazole), in children. Similarly, there is little information regarding the pharmacokinetic profile of antivirals and antifungals in children. Dosage guidelines are available to enable the clinician to initiate anti-infective therapy in children. Subsequent dosage requirements may change based on the patient's current clinical condition. Although several studies have investigated the pharmacokinetics of anti-infectives in neonates and adults, data for children are limited. Therefore, further studies are required so that the ever growing arsenal of anti-infectives can be administered appropriately to children.

Five versus ten days treatment of streptococcal pharyngotonsillitis: a randomized controlled trial comparing cefpodoxime proxetil and phenoxymethyl penicillin

A total of 220 adults and children > 10 years old (mean 29.5 +/- 11.7 years) with pharyngitis/tonsillitis were randomized to receive either cefpodoxime proxetil 100 mg bid for 5 days (n = 113) or phenoxymethyl penicillin, 600 mg tid for 10 days (n = 107). At the end of treatment of the 166 evaluable patients, a satisfactory clinical response was obtained in 85/88 (96.6%) patients treated with cefpodoxime proxetil and in 75/78 (96.1%) treated with phenoxymethyl penicillin. Group A beta-hemolytic streptococci (GABHS) eradication was similar in both groups: 79/82 (96.3%) patients in the cefpodoxime proxetil group and 64/68 (94.1%) patients in the phenoxymethyl penicillin group. At follow-up (20-30 days after the end of treatment) the GABHS eradication persisted in 67/72 (93.1%) patients treated with cefpodoxime proxetil and in 56/61 (91.8%) patients treated with phenoxymethyl penicillin. Significantly better compliance (p < 0.01) was noticed with the cefpodoxime proxetil regimen compared with the phenoxymethyl penicillin regimen, with only 2/110 (2%) poorly compliant patients in the cefpodoxime proxetil group vs 17/104 (16%) in the phenoxymethyl penicillin group. Thus, the shorter duration of therapy, in conjunction with demonstrated clinical and bacteriological efficacy that is equivalent to standard therapy, makes cefpodoxime proxetil an acceptable alternative for the treatment of GABHS pharyngitis/tonsillitis.

Cefpodoxime proxetil: a new, broad-spectrum, oral cephalosporin

OBJECTIVE

To discuss the chemistry, pharmacokinetics, spectrum of activity, clinical trials, adverse effects, drug interactions, and dosage guidelines of cefpodoxime proxetil.

DATA SOURCES

Literature was identified through a MEDLINE search from 1988 to the present and from review of bibliographies in that literature.

STUDY SELECTION

Data were limited to comparative trials published in the English literature. Although many studies were conducted in Japan, the results often were available only in Japanese or partly in English. As these studies could not be completely evaluated, they are not included in this review.

DATA SYNTHESIS

Cefpodoxime exhibits good activity against many gram-positive and gram-negative organisms. In clinical trials, cefpodoxime was similar in both clinical and bacteriologic efficacy to amoxicillin, cefaclor, amoxicillin/clavulanate, and penicillin in the treatment of respiratory and urinary tract infections. It also appeared effective in the treatment of skin and soft tissue infections, although no comparative trials have been performed. Cefpodoxime is well tolerated by children and is effective in the treatment of otitis media and pharyngitis. It has a similar adverse effect profile to that of other penicillins and cephalosporins, with gastrointestinal effects being most common.

CONCLUSIONS

Cefpodoxime demonstrates good in vitro activity against pathogens frequently associated with respiratory tract, urinary tract, and skin and tissue infections. It has not demonstrated greater efficacy than the other antibiotics to which it has been compared. The available published clinical trials are fraught with methodologic, statistical, and evaluative flaws. Thus, further trials comparing cefpodoxime with established treatments, as well as the newer cephalosporins, are needed before its place in therapy can be established.

Penetration of cefprozil into tonsillar and adenoidal tissues

Penetration of cefprozil into tonsillar and/or adenoidal tissues was investigated for patients undergoing tonsillectomy and/or adenoidectomy. A total of 29 patients ranging in age from 2 to 14 years participated in the study. The tonsils and/or the adenoids were removed at times ranging from 0.33 to 3.17 h after oral administration of a dose of either 7.5 or 20 mg/kg of body weight. A blood sample was also collected as soon as the tissue sample was removed. Plasma, tonsil, and adenoid samples were analyzed for cis and trans isomers of cefprozil by high-performance liquid chromatographic assays. The concentrations of the cis isomer of cefprozil in plasma ranged from 0.60 to 9.87 micrograms/ml at the 7.5-mg/kg dose level and from 1.04 to 20.40 micrograms/ml at the 20-mg/kg dose level. The corresponding concentrations of the cis isomer in tonsil tissue ranged from 0.48 to 2.42 micrograms/g and from 1.00 to 4.29 micrograms/g, respectively. The corresponding concentrations of the cis isomer in adenoid tissue ranged from 0.40 to 4.20 micrograms/g and from 1.74 to 4.94 micrograms/g, respectively. The concentrations of the trans isomer were about 1/10 of those observed for the cis isomer. The median ratios of the cefprozil concentration in tonsillar tissue to that in plasma were 0.37 and 0.47 for patients receiving a 7.5- or a 20-mg/kg oral dose of cefprozil, respectively. The corresponding median ratios for the adenoidal tissue were 0.46 and 0.82, respectively. The cefprozil concentrations in either the tonsillar or the adenoidal tissue at both dose levels over 3.17 h after dosing are much higher than the MICs for common pathogens which cause pharyngitis or tonsillitis.

Future directions in antimicrobial chemotherapy

New developments in the treatment of bacterial infections are discussed. The most important developments include oral broad-spectrum cephalosporin derivatives and extended-spectrum injectable cephalosporins with improved activity against Gram-positive bacteria. Meropenem is a new carbapenem agent with markedly improved activity against Gram-negative bacteria. Many fluoroquinolones are in various phases of development. The most interesting new compound is sparfloxacin. Azithromycin is a new macrolide which, because of its very long half-life, attains very high levels in most tissues. Potential uses of the newer agents are discussed.