Risk-based management of dental procedures in patients with inherited bleeding disorders: Development of a Dental Bleeding Risk Assessment and Treatment Tool (DeBRATT).

INTRODUCTION: Successful outcomes in dental management for patients with inherited bleeding disorders require close collaboration between haematology teams and dentists. AIM: To review outcomes of an interdisciplinary pathway for dental procedures by assessing adequacy and appropriateness of haemostatic management. METHODS: Two hundred dental procedures in 30 patients with inherited bleeding disorders were included. A Dental Bleeding Risk Assessment and Treatment Tool (DeBRATT) was developed to identify four categories of bleeding risk (no risk, low, moderate and high risk of bleeding) in relation to the severity of the bleeding disorder and the invasiveness of dental procedure. The adequacy and appropriateness of haemostatic therapy provided in relation to the bleeding risk was assessed with reference to the published literature. Treatment was classified as appropriate, over or under-treatment. Bleeding complication was the primary outcome. RESULTS: A high level of dental disease was noted, with 83% of patients having at least one decayed tooth and 46.7% having chronic gum disease. A total of 59.1% of the dental procedures in patients with mild bleeding disorders were over-treated (n = 65/110) and 8.9% in patients with severe disorders had an extended duration of treatment (n = 7/79). One bleeding complication was observed in a patient with Von Willebrand's disease and severe thrombocytopenia. All other procedures (99.5%) were uneventful. CONCLUSION: DeBRATT enables a risk-based approach for the management of dental procedures in patients with inherited bleeding disorders. The tool facilitates a comprehensive evaluation of bleeding risk with the potential to minimize unnecessary treatment and aid interdisciplinary communication among different clinical teams.

Safety and efficacy of factor XI (FXI) concentrate use in patients with FXI deficiency: a single-centre experience of 19 years.

AIM: Factor XI (FXI) concentrate is a pooled human plasma-derived factor concentrate used as replacement therapy for patients with FXI deficiency, which provides a predictable response and consistent haemostatic cover in emergency or elective situations. It has previously been implicated in adverse events such as thrombosis and inhibitor formation, with rare case reports of fatal incidents. We sought to establish the incidence of such complications in a retrospective case series between 1994 and 2012 at the Haemophilia Comprehensive Care Centre at Royal Free Hospital, London, UK. METHODS: Patients who received FXI concentrate had their medical records reviewed to extract information and specific adverse events recorded such as failure of treatment with further bleeding, suspected viral transfusion transmitted infection (TTI), thrombosis or inhibitor formation. RESULTS: Eighty-six patients received 242 treatment episodes of FXI concentrate. Ninety percent of treatment episodes were covered with BPL FXI concentrate and 10% with LFB Hemoleven. Twelve (5%) adverse events were recorded, with eight (3.3%) of all treatment episodes were related to persistent bleeding postconcentrate infusion and there were 4 (1.7%) non-bleeding adverse events. No viral TTIs were identified. There were two recorded inhibitors, one thrombotic event (central retinal artery occlusion) and one transfusion reaction. No patient suffering an adverse event resulted in long-term morbidity. CONCLUSION: Our experience of FXI concentrate use demonstrates infrequent minor adverse events related to its administration and is a safe product to use.

Carbamazepine toxicity with lamotrigine: pharmacokinetic or pharmacodynamic interaction?

PURPOSE: To determine whether the toxicity that occurs in some patients when lamotrigine (LTG) is added to carbamazepine (CBZ) is the result of either a pharmacokinetic or a pharmacodynamic interaction. METHODS: Escalating LTG doses were added to ongoing CBZ treatment in 47 patients. All patients had blood samples collected for drug concentration measurement, including the epoxide metabolite of CBZ, before starting LTG treatment and after stabilising at each dose escalation. Patients also were examined for signs of toxicity. RESULTS: After LTG was introduced, nine patients demonstrated clinical signs of CNS toxicity, mainly diplopia and dizziness. There was no significant (p = 0.05) change in the serum concentrations of either CBZ or its epoxide metabolite when LTG was added either to the group as a whole or to the nine patients who experienced adverse CNS effects. LTG serum concentrations also were below the level at which the common signs of LTG toxicity, such as nausea, vomiting, or unsteadiness, are more likely to occur. In seven of the nine patients who exhibited CNS toxicity, CBZ serum concentrations were >8 mg/L on LTG introduction. CONCLUSIONS: Toxicity is more likely to occur when LTG is added to CBZ if the initial CBZ level is high, typically >8 mg/L. This appears to be the result of a pharmacodynamic interaction. A reduction of CBZ dose usually resolves the toxicity, allowing the LTG dose to be escalated to maximal effect. It is not usually necessary to stop either drug.