acenocoumarol and Obesity--Morbid

Numerous factors are well documented to affect the response to vitamin K antagonists (VKA), including dietary vitamin K, other drugs, age, pharmacogenetics, and disease states. Body weight is perhaps not as well known as a variable affecting VKA dose. Our aim was to review the literature regarding body weight and VKA dose requirements.. We reviewed the English-language literature via PubMed and Scopus using the search terms VKA, warfarin, acenocoumarol, phenprocoumon, fluindione, AND body weight.. Among 32 studies conducted since the widespread use of the international normalized ratio, 29 found a correlation with body weight or body surface area and VKA dose requirement. Warfarin was evaluated in 27 studies and acenocoumarol, phenprocoumon, or fluindione were assessed in 5 investigations.. Because of varying study methodologies, further study is warranted. Based on current evidence, clinicians should include body weight, along with other established variables when dosing VKA. Most important, obese and morbidly obese patients may require a 30% to 50% increase with the initial dosing of VKA.

Topics: Acenocoumarol; Anticoagulants; Body Weight; Comorbidity; Drug Dosage Calculations; Humans; Obesity; Obesity, Morbid; Phenindione; Phenprocoumon; Vitamin K; Warfarin

Low-molecular-weight heparins are effective as initial therapy for pulmonary embolism (PE) in a weight-based dosing regimen up to known body weights of 160 kg. The present case reports an extremely obese man of 252 kg (body mass index (BMI) 74 kg/m2) with PE who was treated with tinzaparin, dosed on a body weight of 160 kg. Morbid obesity defined as a BMI higher than 40 kg/m2 is becoming more common in general practice, but there are no evidence-based drug dosing strategies for these patients. This case demonstrates the successful use of a maximum dose of 28,000 anti-Xa international units of tinzaparin for an extremely obese patient with proven PE, instead of the accepted doses of 175 IU/kg, as bridge therapy to a coumarin.

Topics: Acenocoumarol; Anticoagulants; Drug Dosage Calculations; Drug Monitoring; Factor Xa; Factor Xa Inhibitors; Fibrinolytic Agents; Heparin, Low-Molecular-Weight; Humans; Male; Middle Aged; Obesity, Morbid; Prothrombin Time; Pulmonary Embolism; Tinzaparin