Empirical treatment of fever in neutropenic children: the role of the carbapenems. International Antimicrobial Therapy Cooperative Group of the European Organisation for Research and Treatment of Cancer and the Gimema Infection Program

Commonly used antibacterial and antifungal agents for hospitalised paediatric patients: implications for therapy with an emphasis on clinical pharmacokinetics

Due to normal growth and development, hospitalised paediatric patients with infection require unique consideration of immune function and drug disposition. Specifically, antibacterial and antifungal pharmacokinetics are influenced by volume of distribution, drug binding and elimination, which are a reflection of changing extracellular fluid volume, quantity and quality of plasma proteins, and renal and hepatic function. However, there is a paucity of data in paediatric patients addressing these issues and many empiric treatment practices are based on adult data. The penicillins and cephalosporins continue to be a mainstay of therapy because of their broad spectrum of activity, clinical efficacy and favourable tolerability profile. These antibacterials rapidly reach peak serum concentrations and readily diffuse into body tissues. Good penetration into the cerebrospinal fluid (CSF) has made the third-generation cephalosporins the agents of choice for the treatment of bacterial meningitis. These drugs are excreted primarily by the kidney. The carbapenems are broad-spectrum beta-lactam antibacterials which can potentially replace combination regimens. Vancomycin is a glycopeptide antibacterial with gram-positive activity useful for the treatment of resistant infections, or for those patients allergic to penicillins and cephalosporins. Volume of distribution is affected by age, gender, and bodyweight. It diffuses well across serous membranes and inflamed meninges. Vancomycin is excreted by the kidneys and is not removed by dialysis. The aminoglycosides continue to serve a useful role in the treatment of gram-negative, enterococcal and mycobacterial infections. Their volume of distribution approximates extracellular space. These drugs are also excreted renally and are removed by haemodialysis. Passage across the blood-brain barrier is poor, even in the face of meningeal inflammation. Low pH found in abscess conditions impairs function. Toxicity needs to be considered. Macrolide antibacterials are frequently used in the treatment of respiratory infections. Parenteral erythromycin can cause phlebitis, which limits its use. Parenteral azithromycin is better tolerated but paediatric pharmacokinetic data are lacking. Clindamycin is frequently used when anaerobic infections are suspected. Good oral absorption makes it a good choice for step-down therapy in intra-abdominal and skeletal infections. The use of quinolones in paediatrics has been restricted and most information available is in cystic fibrosis patients. High oral bioavailability is also important for step-down therapy. Amphotericin B has been the cornerstone of antifungal treatment in hospitalised patients. Its metabolism is poorly understood. The half-life increases with time and can be as long as 15 days after prolonged therapy. Oral absorption is poor. The azole antifungals are being used increasingly. Fluconazole is well tolerated, with high bioavailability and good penetration into the CSF. Itraconazole has greater activity against aspergillus, blastomycosis, histoplasmosis and sporotrichosis, although it's pharmacological and toxicity profiles are not as favourable.

Antimicrobial therapy for infants and children: guidelines for the inpatient and outpatient practice of pediatriac infectious diseases

In this article, we discuss antimicrobial regimens for both outpatient and inpatient use in infants and children. A substantial number of pediatric patient visits annually result in the prescribing of antimicrobial drugs. The emergence of bacteria resistant to commonly used antimicrobial agents is a growing concern. Information on newer drugs such as meropenem, which is active against penicillin-resistant Streptococcus pneumoniae and gram-negative bacilli, and cefepime, which has activity against gram-negative bacilli including Pseudomonas aeruginosa and against gram-positive cocci is also presented. Management of patients with congenital or acquired immunodeficiencies continues to be challenging in regard to the use of antimicrobial drugs to treat various fungal and viral infections. New formulations of older drugs such as aerosolized tobramycin and amphotericin B lipid complex are available. New antiviral agents have been approved, most of which are antiretroviral agents. Childhood tuberculosis is an ongoing concern, and regimens to treat Mycobacterium tuberculosis in children are discussed.

Meropenem compared with ceftazidime in the empiric treatment of acute severe infections in hospitalized children. Italian Pediatric Meropenem Study Group

In a multicenter, randomized, open comparison of meropenem to ceftazidime as empiric treatment of severe acute infections, 185 children (1 mo-15 years old, mean 65.4 mo) were enrolled. Meropenem (20 mg/kg t.i.d. i.v.) was given to 98 and ceftazidime (10-30 mg/kg t.i.d. i.v.) to 87 children, generally for 5 to 10 days (mean: 6.9 for meropenem and 7.5 for ceftazidime). Clinical response was evaluated at the beginning and at the end of therapy and 4 weeks later (follow-up). Clinical response was deemed satisfactory at the end of therapy in 96.7% of the patients treated with meropenem and in 95.3% of those who received ceftazidime without any statistically significant difference. One relapse occurred in a meropenem-treated patient at the follow-up clinical assessment. The baseline infecting organism was eradicated or presumed eradicated at the end of therapy in 14/16 patients treated with meropenem and in 14/15 treated with ceftazidime. The incidence of drug-related adverse events (mostly a slight increase in liver enzymes) was 9.2% in the meropenem group and 4.6% in the ceftazidime group. Our data show that meropenem is as effective as ceftazidime in the empiric treatment of severe infections in infants and children.