scholarly journals Absence of Interactions between Denosumab and Warfarin in Women with Osteoporosis

Reports ◽  
2018 ◽  
Vol 1 (3) ◽  
pp. 20
Author(s):  
Vincenzo Polimeni ◽  
Gianluca Sottilotta ◽  
Fabiola Branca ◽  
Nadia Mammone ◽  
Antonio Panuccio
Keyword(s):  
Monoclonal Antibody ◽  
Bone Resorption ◽  
Prothrombin Time ◽  
Therapeutic Range ◽  
Oral Anticoagulant ◽  
International Normalized Ratio ◽  
Prevention And Treatment ◽  
Anticoagulated Patients

The monoclonal antibody denosumab reduces bone resorption. Warfarin is an oral anticoagulant used in the prevention and treatment of thrombosis. To date, there have been no studies on the interaction between warfarin and denosumab. The aim of the present study was to assess the maintenance of the Prothrombin Time International Normalized Ratio (INR) in the therapeutic range (TTR) in women under treatment with warfarin and denosumab, in order to evaluate the pharmacological interference of denosumab. No variations of the median TTR were found after undergoing treatment with denosumab: this shows that the intake of denosumab does not require additional checks in anticoagulated patients.

scholarly journals Effectivity of a joint didactic intervention by School for Patients on inappropriate control prothrombin time anticoagulated patients. Protocol for developing a randomized and controlled clinical trial.

2020 ◽  
Author(s):  
Leovigildo Ginel-Mendoza ◽  
Alfonso Hidalgo Hidalgo-Natera ◽  
Rocio Reina-Gonzalez ◽  
Rafael Poyato-Ramos ◽  
Inmaculada Lupianez-Perez ◽  
...  
Keyword(s):  
Social Support ◽  
Clinical Trial ◽  
Prothrombin Time ◽  
Vitamin K ◽  
Oral Anticoagulant ◽  
Vitamin K Antagonists ◽  
International Normalized Ratio ◽  
Control Group ◽  
Therapeutic Level ◽  
Anticoagulated Patients

Abstract Background Oral anticoagulant drugs represent an essential tool in thrombo-embolic events prevention. Most used are vitamin K antagonists, whose plasma level is monitored by measuring prothrombin time using the International Normalized Ratio. If it takes values out of the recommended range, the patient will have a higher risk of suffering from thromboembolic or hemorrhagic complications. Previous research has shown that about 33% of total patients keep values on inappropriate level. The purpose of the study is to improve International Normalized Ratio control figures by a joint didactic intervention based on the Junta de Andalucía School for Patients method that will be implemented by anticoagulated patients themselves. Methods A randomized clinical trial was carried out at primary care centers from one healthcare area in Málaga (Andalusia, Spain). Study population: patients included in an oral anticoagulant therapy program consisting in using vitamin K antagonists. First step detection of patients on oral anticoagulation program with International Normalized Ratio control on therapeutic level during 65% or less over total time. Second step: patients with inappropriate International Normalized Ratio control were included in two groups: Group 1 or Joint Intervention Group: patients were instructed a joint didactic intervention “from peer to peer”, by a previously trained and expert anticoagulated patient. Group 2 or Control Group: Control group performed usual clinical practice: people were schedule by nurses about one time per month, except cases in which controls were inappropriate; in those circumstances patients were schedule before that period expired. In order to built the study group and the control group, 312 individuals were required (156 in each group) to detect differences in INR figures equal or higher than 15% between both groups. Study variables time on therapeutic levels before and after intervention, sociodemographic variables, vital signs, existence of cardiovascular risk factors or accompanying diseases in the clinical records, laboratory test including complete blood count, bleeding time, and prothrombin time or partial thromboplastin time and blood chemistry, other prescribed drugs, and social support. Almost-experimental analytic study with before-after statistical analysis of the intervention were made. Lineal regression models were applied on main variables results (International Normalized Ratio value, time on therapeutic level) inputting sociodemographic variables, accompanying diseases and social support.

Relationship Between Total Prothrombin, Native Prothrombin and the International Normalized Ratio (INR)

1992 ◽  
Vol 68 (02) ◽  
pp. 160-164 ◽  
Author(s):  
P J Braun ◽  
K M Szewczyk
Keyword(s):  
Anticoagulant Therapy ◽  
Oral Anticoagulant ◽  
Inverse Relationship ◽  
Low Dose ◽  
Oral Anticoagulant Therapy ◽  
International Normalized Ratio ◽  
Antigen Assay ◽  
Dose Oral ◽  
Anticoagulated Patients ◽  
Sensitive Method

SummaryPlasma levels of total prothrombin and fully-carboxylated (native) prothrombin were compared with results of prothrombin time (PT) assays for patients undergoing oral anticoagulant therapy. Mean concentrations of total and native prothrombin in non-anticoagulated patients were 119 ± 13 µg/ml and 118 ± 22 µg/ml, respectively. In anticoagulated patients, INR values ranged as high as 9, and levels of total prothrombin and native prothrombin decreased with increasing INR to minimum values of 40 µg/ml and 5 µg/ml, respectively. Des-carboxy-prothrombin increased with INR, to a maximum of 60 µg/ml. The strongest correlation was observed between native prothrombin and the reciprocal of the INR (1/INR) (r = 0.89, slope = 122 µg/ml, n = 200). These results indicated that native prothrombin varied over a wider range and was more closely related to INR values than either total or des-carboxy-prothrombin. Levels of native prothrombin were decreased 2-fold from normal levels at INR = 2, indicating that the native prothrombin antigen assay may be a sensitive method for monitoring low-dose oral anticoagulant therapy. The inverse relationship between concentration of native prothrombin and INR may help in identification of appropriate therapeutic ranges for oral anticoagulant therapy.

scholarly journals Preanalytical Variables and Off-Site Blood Collection: Influences on the Results of the Prothrombin Time/International Normalized Ratio Test and Implications for Monitoring of Oral Anticoagulant Therapy

2005 ◽  
Vol 51 (3) ◽  
pp. 561-568 ◽  
Author(s):  
Johanna HH van Geest-Daalderop ◽  
André B Mulder ◽  
Leandra JM Boonman-de Winter ◽  
Martha MCL Hoekstra ◽  
Anton MHP van den Besselaar
Keyword(s):  
Prothrombin Time ◽  
Anticoagulant Therapy ◽  
Oral Anticoagulant ◽  
Room Temperature ◽  
Oral Anticoagulant Therapy ◽  
International Normalized Ratio ◽  
Blood Collection ◽  
Ratio Test ◽  
Mechanical Agitation ◽  
The Impact

Abstract Background: The quality of oral anticoagulant therapy management with coumarin derivatives requires reliable results for the prothrombin time/International Normalized Ratio (PT/INR). We assessed the effect on PT/INR of preanalytical variables, including ones related to off-site blood collection and transportation to a laboratory. Methods: Four laboratories with different combinations of blood collection systems, thromboplastin reagents, and coagulation meters participated. The simulated preanalytical variables included time between blood collection and PT/INR determinations on samples stored at room temperature, at 4–6 °C, and at 37 °C; mechanical agitation at room temperature, at 4–6 °C, and at 37 °C; time between centrifugation and PT/INR determination; and times and temperatures of centrifugation. For variables that affected results, the effect of the variable was classified as moderate when <25% of samples showed a change >10% or as large if >25% of samples showed such a change. Results: During the first 6 h after blood collection, INR changed by >10% in <25% of samples (moderate effect) when blood samples were stored at room temperature, 4–6 °C, or 37 °C with or without mechanical agitation and independent of the time of centrifugation after blood collection. With one combination of materials and preanalytical conditions, a 24-h delay at room temperature or 4–6 °C had a large effect, i.e., changes >10% in >25% of samples. In all laboratories, a 24-h delay at 37 °C or with mechanical agitation had a large effect. We observed no clinically or statistically relevant INR differences among studied centrifugation conditions (centrifugation temperature, 20 °C or no temperature control; centrifugation time, 5 or 10 min). Conclusions: We recommend a maximum of 6 h between blood collection and PT/INR determination. The impact of a 24-h delay should be investigated for each combination of materials and conditions.

MC-SAT: A Telemedicine Management System Utilized to Monitor Oral Vitamin K Antagonists Treatment

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 4742-4742
Author(s):  
Diana Irina Iosub ◽  
Barone Marisa ◽  
Chiara Beltrametti ◽  
Stefano Barco ◽  
Picchi Chiara ◽  
...  
Keyword(s):  
Prothrombin Time ◽  
General Practitioners ◽  
Therapeutic Range ◽  
Oral Anticoagulant ◽  
Anticoagulation Clinic ◽  
Anticoagulant Treatment ◽  
Oral Anticoagulant Treatment ◽  
Telemedicine System ◽  
Portable Monitor ◽  
Do So

Abstract Abstract 4742 The MC-SAT program is a telemedicine system developed for the management of patients under oral anticoagulant treatment (OAT). The program constitutes the natural evolution of an original research project, which assessed the capability of a telematic system in managing different chronic patients access flow to health care services. In particular, for patients on oral anticoagulation we planned a direct access to a call center server and a pre-process of the INR data obtained through self-testing with portable prothrombin time (PT) monitor. The original project performed the technology assessment of all the devices and procedures able to automatically drive international normalization ratio (INR) data from patients to specialists in a hospital anticoagulation clinic and to get patients able to read the medical answer. The ability of patients and/or general practitioners to self-determine INR without specific training and the integration of a portable PT monitor for home use into routine patient care in anticoagulation clinics was subsequently successfully evaluated. After a pilot phase of the project, during which the feasibility of the MC-SAT telemedicine service was assessed, we started the enrollment of consecutive patients. Controls matched by age (+/− 5 years), sex and therapeutic range with the cases, were selected among those who attended our anticoagulation clinic (whose population reaches 3,557 individuals) and were managed by usual care. At the beginning of the program, which is still ongoing, a portable monitor (Coagucheck®, Roche Diagnostics, Germany) has been given to 40 patients and to 10 general practitioners (GPs) provided with portable monitors and Internet access. Each GP had the task to follow 5 patients on chronic OAT. Subsequently, additional 40 patients joined, referring to the preferred community laboratory to perform the prothrombin time and subsequently send the INR results through MC-SAT. To date, the system works like this: the INR data, obtained through the portable monitor or through a local laboratory, is sent by GPRS cellular phone or by Internet computer. When an alert output is detected, an automatic message is sent to the specialist. GPRS services are implemented in order to connect the specialist to the database containing the clinical history of the patient. The specialist is able to monitor, from any location, by means of smartphone or tablet PC, all INR values recorded by the system, all the previous patient accesses to the hospital and the last weekly OAT dose. On these basis, if necessary, a change of the weekly OAT doses is made and transferred to the GP's or patients' computer. Since the start of this project in its definitive shape in june 2009, we enrolled 130 patients allocated to prolonged oral anticoagulant treatment. Of these, 80 were directly assisted by our clinic. The remaining 50 patients were assigned to the GPs. Of the 130 patients originally enrolled, 39 never provided any data. These 39 patients were among those assigned to the GPs. Even if periodically urged to do so, GPs sent data on 11 patiens only. Of the 80 patients directly assisted by our clinic, who utilized either the given portable monitor or referred to a community laboratory, 69 showed great interest to the program, did send their results and continue to do so, utilizing the system 1104 times during the period july 2010-june 2011, with a mean of 16 prescription/year/patient. No significant differences were recorded in the TTR (time in therapeutic range) between the patients enrolled and the controls. More than 80% of the answers were given before 9 hours from the request. After two years, we confirm that the use of the system represents an improvement in the management of patients under oral anticoagulant treatment, by favouring communications and, potentially, clinical outcomes. The program showed to work better when it involves the individual patient rather than GPs. Disclosures: No relevant conflicts of interest to declare.

Interpretation of serial measurements of international normalized ratio for prothrombin times in monitoring oral anticoagulant therapy

1995 ◽  
Vol 41 (8) ◽  
pp. 1171-1176 ◽  
Author(s):  
J F Lassen ◽  
J Kjeldsen ◽  
S Antonsen ◽  
P Hyltoft Petersen ◽  
I Brandslund
Keyword(s):  
Opposite Direction ◽  
Therapeutic Range ◽  
Oral Anticoagulant ◽  
Oral Anticoagulant Therapy ◽  
International Normalized Ratio ◽  
Random Fluctuation ◽  
Objective Criterion ◽  
Oral Anticoagulant Treatment ◽  
Increased Risk ◽  
Serial Measurements

Abstract Despite careful monitoring of oral anticoagulant treatment (OAT), some international normalized ratio (INR) for prothrombin time values will fall outside the therapeutic range. Considerable changes in serial INR results from OAT patients may be caused by random fluctuation alone, and, for statistical reasons, a fraction of the INR values will fall outside therapeutic range and interfere with dose adjustments. On the basis of therapeutic intervals and statistical evaluation of reference changes, we suggest and discuss an alternative method for interpretation of serial INR measurements. Retrospective evaluation of serial measurements of INR from OAT patients revealed an "overshooting" phenomenon. When a dose was adjusted on the basis of insignificant change in INR value, the subsequent INR value generally fell in the opposite direction. If a further change of dose was initiated because of the new INR value, a similar course in the opposite direction was observed. This "ping-pong" effect renders patients in a fluctuating state of anticoagulation and may introduce increased risk of complications. The suggested method provides an objective criterion for dose adjustments in OAT, which should reduce patients' risk.

scholarly journals Anti-Xa and Anti-IIa Drugs Alter International Normalized Ratio Measurements: Potential Problems in the Monitoring of Oral Anticoagulants

2004 ◽  
Vol 10 (4) ◽  
pp. 301-309 ◽  
Author(s):  
Mahmut Tobu ◽  
Omer Iqbal ◽  
Debra Hoppensteadt ◽  
Brian Neville ◽  
Harry L. Messmore ◽  
...  
Keyword(s):  
Prothrombin Time ◽  
Oral Anticoagulant ◽  
Warfarin Therapy ◽  
Oral Anticoagulants ◽  
International Normalized Ratio ◽  
Therapeutic Monitoring ◽  
Recombinant Hirudin ◽  
Therapeutic Implications ◽  
Anticoagulant Drugs ◽  
Dosage Errors

Several of the newly developed anti-Xa and anti-IIa agents have been shown to influence the International Normalized Ratio (INR) values. During phase I trials with normal healthy volunters and phase II study patients who were given warfarin and concomitant anti-IIa or anti-Xa agents, it has been reported that INR values were falsely elevated. It is of critical importance to know of the effects of these agents on INR to avoid dosage errors. To study the influence of these agents on INR, we used several anti-IIa agents (argatroban, recombinant hirudin, efegatran, and PEG-hirudin) and anti-Xa drugs (pentasaccharides such as fondaparinux and idraparinux, DX-9065a and JTV-803). The anti-IIa drugs were supplemented in citrated plasma at a concentration of 0 to 1 μg/mL level and anti-Xa drugs in the range of 0 to 25 μg/mL. The IC50 values for each of these agents were calculated. Four different commercially available prothrombin time (PT) reagents were used to perform the PT assays and to calculate the relative INR values. Direct synthetic factor IIa and Xa inhibitors exhibited a concentration-dependent increase in the INR values. Hirudin, efegatran, and PEG-hirudin showed a weaker effect, whereas argatroban showed a much higher elevation of the INR values. Synthetic indirect anti-Xa agents such as the pentasaccharide did not show any effect on the INR values. Furthermore, prothrombin time reagents with high ISI values exhibited disproportionally higher INR values for both the direct anti-Xa and anti-IIa agents. Elevation of INR values has therapeutic implications when non-oral anticoagulant drugs are used in combination with drugs such as warfarin. Because of the false elevation of INR values with some of the non-oral anticoagulant drugs, patients who are on concomitant warfarin therapy should be carefully evaluated for their corresponding INR values for proper dosing. To avoid dosing errors it is best not to use the INR values in the therapeutic monitoring of anti-Xa and anti-IIa agents either in the monotherapeutic or polytherapeutic modalities. These data also warrant the development clinically relevant methods for the monitoring of the concomitant use of newly developed anti-Xa and anti-IIa drugs with oral anticoagulants.

Sign in / Sign up

Export Citation Format

Share Document