Dosing and monitoring of low-molecular-weight heparins in special populations.

As a result of numerous clinical trials and meta-analyses supporting the superior efficacy and relative safety of low-molecular-weight heparins (LMWHs) compared with unfractionated heparin (UFH), LMWHs are emerging as the antithrombotic agents of choice for the prevention and treatment of deep vein thrombosis and pulmonary embolism. In addition, data indicate that enoxaparin given with low-dosage aspirin is more effective than UFH in treating acute coronary syndromes. Anti-Xa activity can be used as a biologic marker of LMWH activity. Because of the more predictable anticoagulant response to subcutaneous administration of LMWHs compared with UFH, routine monitoring of anti-Xa activity in clinically stable adults with uncomplicated disease is not recommended. Because the optimal dosage of LMWHs has not been established for patients with renal insufficiency or extremes of body weight, during pregnancy, or for children, anti-Xa activity monitoring may be warranted in these subsets.

Treatment of childhood hypercholesterolemia with HMG-CoA reductase inhibitors.

OBJECTIVE: To describe the development of coronary artery disease in childhood and review the available literature regarding the safety and efficacy of hydroxymethylglutaryl coenzyme A (HMG-CoA) reductase inhibitors (statins) when used during childhood and adolescence. DATA SOURCES: A MEDLINE search was performed for the period of January 1966 through January 1999 using the key terms hypercholesterolemia, hyperlipidemia, and hydroxymethylglutaryl CoA reductase inhibitors. The search was further limited to English language, human study group, and all-child (0-18 y) age group. STUDY SELECTION AND DATA EXTRACTION: All clinical studies involving the use of HMG-CoA reductase inhibitors exclusively during childhood or adolescence were evaluated. DATA SYNTHESIS: A mean low-density lipoprotein cholesterol (LDL-C) concentration reduction of 25% can be obtained in children and adolescents treated with lovastatin, pravastatin, or simvastatin along with a lipid-lowering diet. The statins are generally well-tolerated in children and adolescents. Transient, asymptomatic elevations in creatine phosphokinase and hepatic transaminase concentrations have been reported in a small number of the children evaluated. Current data do not suggest any adverse effects on normal growth and sexual development in male adolescents, but formal evaluations have not been performed in female adolescents. CONCLUSIONS: The addition of the HMG-CoA reductase inhibitors lovastatin, pravastatin, or simvastatin to diet therapy in children > or =10 years of age may be effective when diet therapy alone has failed to obtain the recommended maximum LDL-C concentration of 130 mg/dL. The use of statins during childhood and adolescence is generally safe, but large, long-term studies should be performed before statins are routinely prescribed to children with elevated cholesterol or lipoprotein concentrations.