warfarin and Muscular-Diseases

Possible procoagulant effects can occur when lipid-lowering fibric acid derivatives, such as gemfibrozil and fenofibrate, are taken concomitantly with warfarin. Although there are several detailed reports of fenofibrate potentiating the anticoagulant effects of warfarin, few case reports have been published regarding an interaction between gemfibrozil and warfarin. We describe a 62-year-old man who was taking warfarin for paroxysmal atrial fibrillation and came to the anticoagulation clinic for a routine follow-up. For 9 months, the patient's international normalized ratio (INR) had been stable (target range 2.0-3.0) with warfarin 45 mg/week. At this clinic visit, however, his INR was supratherapeutic at 5.8; the only identified change in his drug therapy was the addition of gemfibrozil 600 mg twice/day, started 3 weeks earlier. The patient denied any changes in his dietary intake of vitamin K, alcohol use, or addition of nonprescription or herbal agents. Recent laboratory tests revealed no signs of thyroid abnormalities and only an insignificant elevation in his alanine aminotransferase level. His warfarin dose was decreased to 35-37.5 mg/week (a 22% reduction), and a therapeutic INR was maintained until gemfibrozil was later discontinued because of myalgia. After consecutive subtherapeutic INRs, his warfarin dose was increased to 45 mg/week and a therapeutic INR was maintained. Use of the Drug Interaction Probability Scale indicated that the likelihood of the gemfibrozil-warfarin interaction was probable. The exact mechanism of the proposed interactions between fibric acid derivatives and warfarin remains unknown but may be multifactorial through inhibition of cytochrome P450 isoenzymes, displacement from protein binding sites, or changes in coagulation factor synthesis. Regardless of the fibric acid derivative chosen, an empiric dosage reduction of 20% and close INR monitoring are warranted in patients receiving warfarin.

Topics: Anticoagulants; Atrial Fibrillation; Drug Interactions; Follow-Up Studies; Gemfibrozil; Humans; Hypolipidemic Agents; International Normalized Ratio; Male; Middle Aged; Muscular Diseases; Time Factors; Treatment Outcome; Warfarin

The article is based upon two adverse drug reaction reports after switch from atorvastatin to simvastatin. Simvastatin interactions with warfarin and the cytochrome P450-3A4 inhibitor diltiazem were suspected as possible causes of the events (fatal intracranial haemorrhage with INR > 8 and myopathy). Relevant literature was examined to evaluate potential differences in atorvastatin and simvastatin interaction profiles.. Relevant interaction studies were identified through searches in the databases PubMed and ISI Web of Knowledge. Interaction databases referring to primary sources and product monographs were also examined.. One interaction study was found for the warfarin-atorvastatin combination, but this showed no relevant changes in prothrombin time. Three interaction studies were identified for the combination warfarin-simvastatin and these showed consistently increased INR and/or reduced dose requirements for warfarin (10-30%) after starting treatment with simvastatin. Three studies had investigated the degree to which simvastatin and atorvastatin interact with a CYP3A4 inhibitor in the same population. In these studies, plasma concentrations of both statins increased, but the increases were several times greater for simvastatin than for atorvastatin.. Interaction studies show that atorvastatin and simvastatin display differences in interaction potential toward warfarin and drugs inhibiting CYP3A4 metabolism. It is important to consider the risk of interactions when switching to or starting simvastatin treatment.

Topics: Anticholesteremic Agents; Anticoagulants; Antihypertensive Agents; Aryl Hydrocarbon Hydroxylases; Atorvastatin; Diltiazem; Drug Interactions; Drug Therapy, Combination; Heptanoic Acids; Humans; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Intracranial Hemorrhages; Muscular Diseases; Pyrroles; Risk Factors; Simvastatin; Warfarin

Topics: Abdominal Pain; Aged; Anemia; Anticoagulants; Erythrocyte Transfusion; Female; Hematoma; Humans; International Normalized Ratio; Muscular Diseases; Rectus Abdominis; Tomography, X-Ray Computed; Treatment Outcome; Warfarin

A patient started anticoagulation for secondary prevention of stroke, achieving a prothrombin time-international normalized ratio within the optimal therapeutic range. The patient subsequently complained of pain in the left thigh on hospital day 25, and ultrasonography showed a large intramuscular hematoma in the left hamstring. The intramuscular hematoma gradually reduced without surgical intervention. Ultrasound examination plays an important role in precisely diagnosing intramuscular hematoma and monitoring changes in hematoma size.

Topics: Aged; Anticoagulants; Biomechanical Phenomena; Hematoma; Humans; Male; Muscle, Skeletal; Muscular Diseases; Stress, Mechanical; Thigh; Ultrasonography; Warfarin

Topics: Aged, 80 and over; Anemia; Antibiotics, Antitubercular; Anticoagulants; Drug Interactions; Hematoma; Humans; Male; Muscular Diseases; Polypharmacy; Rifampin; Risk; Warfarin

Although needle electromyography (EMG) appears to be a relatively safe procedure based primarily on clinical experience, no evidence-based guidelines exist for EMG procedures in patients taking anticoagulant or antiplatelet medications. We sought to determine whether there is an increased risk of hematoma formation after EMG of potentially high-risk muscles in patients taking anticoagulant or antiplatelet agents.. After undergoing routine EMG, if any of seven predetermined high-risk muscles were tested, study subjects then underwent ultrasound to evaluate for hematoma formation.. Patients were divided into three groups based on medication (warfarin, aspirin/clopidogrel, no blood-thinning medication), with at least 100 muscles examined per group. Two small, subclinical hematomas were seen on ultrasound; there was no difference in hematoma risk between groups (P = 0.43).. Our findings suggest that hematoma formation from standard needle EMG is rare even in high-risk muscles, which have been avoided historically in anticoagulated patients.

Topics: Adult; Aged; Aged, 80 and over; Anticoagulants; Case-Control Studies; Clopidogrel; Electromyography; Female; Hematoma; Humans; Male; Middle Aged; Muscular Diseases; Needles; Platelet Aggregation Inhibitors; Prospective Studies; Risk Factors; Ticlopidine; Ultrasonography, Doppler; Warfarin; Young Adult

Topics: Abdominal Pain; Adult; Anticoagulants; Aortic Valve; Heart Valve Prosthesis; Hematoma; Hemophilia A; Humans; Male; Muscular Diseases; Psoas Muscles; Tomography, X-Ray Computed; Warfarin

Topics: Abdominal Pain; Acute Disease; Aged, 80 and over; Anticoagulants; Female; Hematoma; Humans; Male; Muscular Diseases; Rectus Abdominis; Treatment Outcome; Warfarin

The haematoma in the sheath of musculus rectus abdominis is a rare clinical entity. Its diagnosis is often difficult. Authors observed it in three patients who were on anticoagulant therapy. All subjects were female; two of them had decreased renal function. All three patients received thrombocyte aggregation inhibitor therapy as well. The anticoagulant treatment (low molecular weight heparin in two cases, warfarin in one case) caused excessive anticoagulant effect. The diagnosis, which could be suspected after the physical examination, was established in two cases by ultrasonography and in one case by computed tomography. Two patients were surgically treated while the third patient was healed with conservative treatment. To prevent the rectus sheath haematoma, authors suggest a particularly careful control of anticoagulant treatment in older females and in subjects with decreased renal function, especially if the patient takes thrombocyte aggregation inhibitors, too.

Topics: Aged; Anticoagulants; Female; Hematoma; Heparin, Low-Molecular-Weight; Humans; Muscular Diseases; Platelet Aggregation Inhibitors; Rectus Abdominis; Tomography, X-Ray Computed; Ultrasonography; Warfarin

Rectus sheath haematoma (RSH) is an uncommon condition with a propensity for difficult and mistaken diagnosis. We describe a case where management was complicated by the patient's requirement for anticoagulation.

Topics: Abdominal Pain; Aged, 80 and over; Anticoagulants; Disease Progression; Emergency Service, Hospital; Fatal Outcome; Hematoma; Heparin; Humans; Male; Muscular Diseases; Pulmonary Embolism; Rectus Abdominis; Risk Assessment; Tomography, X-Ray Computed; Warfarin

Topics: Administration, Oral; Anticoagulants; Hematoma; Hemorrhage; Humans; Male; Middle Aged; Muscular Diseases; Shock, Hemorrhagic; Tomography, X-Ray Computed; Treatment Outcome; Warfarin

Topics: Anticoagulants; Choline Kinase; Fluorobenzenes; Humans; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Male; Middle Aged; Muscular Diseases; Pleurodynia, Epidemic; Pyrimidines; Rosuvastatin Calcium; Sulfonamides; Warfarin

Portal vein thrombosis (PVT) is a complication of hepatic disease and a potentially lethal complication of splenectomy. The reported incidence of this complication is low (approximately 1%). However, its true incidence may have been underestimated due to difficulty in making the diagnosis. Herein we report the case of a 19 year-old woman who presented with a 2-year history of idiopathic thrombocytopenic purpura (ITP). Because she had become refractory to medical therapy, she underwent laparoscopic splenectomy. She was discharged on postoperative day 2 after an uncomplicated procedure. She did well, complaining only of mild backache, until postoperative day 21, when she presented with nausea, vomiting, and leukocytosis. CT showed PVT and superior mesenteric vein thrombosis. Despite heparin and fluid administration, her condition worsened. At laparotomy, she had diffuse small bowel edema and congestion. At a second-look procedure 24 h later, nearly all her jejunum and ileum were necrotic. After three procedures, she was left with 45 cm of proximal and 10 cm of distal small bowel. Bowel continuity was restored 8 weeks later. She continued on warfarin anticoagulation therapy for 1 year. Postsplenectomy PVT is most often seen following splenectomy for myeloproliferative disorders and almost never after trauma. The large splenic vein stump and the hypercoagulable state in patients with splenomegaly are thought to be contributory. The presentation of PVT is vague, without defining signs or symptoms. Color-flow Doppler and contrast-enhanced CT scans are the best methods for the nonoperative diagnosis of PVT. Aggressive thrombolysis offers the best hope for clot lysis and maintenance of bowel viability. Even vague symptoms must be considered seriously following splenectomy.

Topics: Adult; Anastomosis, Surgical; Anticoagulants; Back Pain; Combined Modality Therapy; Crystalloid Solutions; Diagnostic Errors; Female; Fluid Therapy; Heparin; Humans; Ileum; Immunosuppressive Agents; Ischemia; Isotonic Solutions; Jejunum; Laparoscopy; Mesenteric Veins; Muscular Diseases; Necrosis; Parenteral Nutrition; Plasma Substitutes; Plasmapheresis; Platelet Transfusion; Portal Vein; Postoperative Complications; Purpura, Thrombocytopenic, Idiopathic; Splenectomy; Splenomegaly; Venous Thrombosis; Warfarin

Abdominal wall haematomas are uncommon, difficult to diagnose clinically and often associated with systemic anti-coagulation. Seven cases together with the imaging results are presented and the characteristic features and potential pitfalls are discussed. Ultrasound is the first line investigation but the results can be misleading and computed tomography (CT) is often required to confirm the diagnosis.

Topics: Abdominal Muscles; Aged; Anticoagulants; Female; Hematoma; Heparin; Humans; Male; Middle Aged; Muscular Diseases; Tomography, X-Ray Computed; Ultrasonography; Warfarin

An unusual case of bilateral femoral nerve compression caused by iliacus hematomas in a patient on anticoagulant therapy is herein reported with special reference to the comparative diagnostic value of ultrasonography, computerized tomorgraphy, and magnetic resonance imaging. The importance of early surgical decompression is also emphasized.

Topics: Adult; Female; Femoral Nerve; Hematoma; Humans; Magnetic Resonance Imaging; Muscular Diseases; Nerve Compression Syndromes; Retroperitoneal Space; Warfarin

We present the case of a 28-year-old man on chronic warfarin therapy who sustained a minor muscle tear and developed increasing pain and a flexure contracture of the right hip. Surgical exploration revealed an iliopsoas hematoma and femoral nerve entrapment, resulting in a femoral nerve palsy and partial loss of quadriceps functions. Anticoagulant-induced femoral nerve palsy represents the most common form of warfarin-induced peripheral neuropathy; it is characterized by severe pain in the inguinal region, varying degrees of motor and sensory impairment, and flexure contracture of the involved extremity.

Topics: Adult; Femoral Nerve; Hematoma; Humans; Male; Muscular Diseases; Nerve Compression Syndromes; Paralysis; Thigh; Warfarin

A case of femoral neuropathy secondary to psoas muscle hematoma in a patient on warfarin sodium anticoagulation therapy is presented. Computed tomography was used to establish the diagnosis. The literature is reviewed with regard to the pathophysiology, clinical presentation, and therapy of this case. Surgical decompression is suggested to shorten the recovery period and minimize residual neurological deficit.

Topics: Femoral Nerve; Hematoma; Humans; Male; Middle Aged; Muscular Diseases; Nerve Compression Syndromes; Peritoneum; Radiography; Warfarin

Topics: Acenocoumarol; Adult; Anticoagulants; Femoral Nerve; Hematoma; Humans; Ilium; Male; Middle Aged; Muscular Diseases; Nerve Compression Syndromes; Tomography, X-Ray Computed; Warfarin

Of five patients in who sciatic paresis developed as the result of hemorrhage and hematoma following hip surgery, four were receiving prophylactic or therapeutic anticoagulants. The patient who was managed expectantly still had disabling motor and sensory deficity at follow-up. Three patients who had early operative decompression showed more complete return of nerve function. The fifth patient died three weeks after onset with the neuropathy still present. Severe low-back and buttock pain, ecchymosis over these regions, marked swelling in the thigh, sciatic-nerve tenderness, and a distal sciatic neural deficit in the ipsilateral lower limb of a patient who has had hip surgery are evidence of hemorrhage in the vicinity of the sciatic nerve. Early recognition and prompt surgical decompression can prevent irreversible nerve damage.

Topics: Adolescent; Adult; Aged; Arthroplasty; Female; Hematoma; Hemorrhage; Heparin; Hip Joint; Humans; Leg; Male; Middle Aged; Muscles; Muscular Diseases; Nerve Compression Syndromes; Paralysis; Postoperative Care; Sciatic Nerve; Warfarin

Topics: Adult; Anticoagulants; Dyspnea; Female; Hemorrhage; Heparin; Humans; Male; Middle Aged; Muscular Diseases; Peripheral Nervous System Diseases; Pregnancy; Warfarin; Wounds and Injuries

Topics: Abdominal Muscles; Aged; Hematoma; Heparin; Humans; Male; Muscular Diseases; Warfarin