OBJECTIVES: The objective was to assess whether the concurrent use of tramadol and vitamin K antagonists (VKAs) leads to an increased risk of excessive anticoagulation. DESIGN: The study was designed as a case-control study, nested within users of VKA and with tramadol use as our main exposure. We used conditional logistic regression to control for potential confounders. SETTING: Prescription data from primary care were obtained from Odense Pharmacoepidemiological Database (OPED). Information about hospital admissions was obtained from the patient administrative system of Funen County (FPAS). SUBJECTS: Both cases and controls were selected from users of VKA. Cases were defined by being hospitalised with a main diagnosis indicating excessive anticoagulation. For each case, we selected 15 controls among VKA users, matched by age and sex. MAIN OUTCOME MEASURE: Odds ratio for experiencing excessive anticoagulation attributable to the use of tramadol. RESULTS: A total of 178 patients were included, 30 of which were exposed to tramadol, along with 2643 controls, 114 of which were exposed to tramadol. The adjusted odds-ratio for experiencing excessive anticoagulation during use of tramadol was 3.1 (1.9-5.2). This corresponds to, on average, one excess case per 250 treatment years (CI 125-584). The result is potentially confounded by concomitant paracetamol use and the presence of acute illness. CONCLUSION: Caution is advised when using tramadol in patients using VKA, and if possible, an alternative pain-medication should be used.
OBJECTIVES: The objective was to assess whether the concurrent use of tramadol and vitamin K antagonists (VKAs) leads to an increased risk of excessive anticoagulation. DESIGN: The study was designed as a case-control study, nested within users of VKA and with tramadol use as our main exposure. We used conditional logistic regression to control for potential confounders. SETTING: Prescription data from primary care were obtained from Odense Pharmacoepidemiological Database (OPED). Information about hospital admissions was obtained from the patient administrative system of Funen County (FPAS). SUBJECTS: Both cases and controls were selected from users of VKA. Cases were defined by being hospitalised with a main diagnosis indicating excessive anticoagulation. For each case, we selected 15 controls among VKA users, matched by age and sex. MAIN OUTCOME MEASURE: Odds ratio for experiencing excessive anticoagulation attributable to the use of tramadol. RESULTS: A total of 178 patients were included, 30 of which were exposed to tramadol, along with 2643 controls, 114 of which were exposed to tramadol. The adjusted odds-ratio for experiencing excessive anticoagulation during use of tramadol was 3.1 (1.9-5.2). This corresponds to, on average, one excess case per 250 treatment years (CI 125-584). The result is potentially confounded by concomitant paracetamol use and the presence of acute illness. CONCLUSION: Caution is advised when using tramadol in patients using VKA, and if possible, an alternative pain-medication should be used.
Authors: G Palareti; N Leali; S Coccheri; M Poggi; C Manotti; A D'Angelo; V Pengo; N Erba; M Moia; N Ciavarella; G Devoto; M Berrettini; S Musolesi Journal: Lancet Date: 1996-08-17 Impact factor: 79.321
Authors: Jenni Ilomäki; Arja Helin-Salmivaara; Risto Huupponen; Maria Rikala; Carl M Kirkpatrick; Maarit Jaana Korhonen Journal: Eur J Clin Pharmacol Date: 2015-04-26 Impact factor: 2.953
Authors: Samuli Jaakkola; Ilpo Nuotio; Tuomas O Kiviniemi; Raine Virtanen; Melina Issakoff; K E Juhani Airaksinen Journal: PLoS One Date: 2017-04-20 Impact factor: 3.240