Haemorrhagic risk
Dabigatran etexilate should be used with caution in conditions with an increased risk of bleeding or with concomitant use of medicinal products affecting haemostasis by inhibition of platelet aggregation. Bleeding can occur at any site during therapy. An unexplained fall in haemoglobin and/or haematocrit or blood pressure should lead to a search for a bleeding site.
The efficacy and safety of the specific reversal agent idarucizumab used for adult patients in situations of life-threatening or uncontrolled bleeding, when rapid reversal of the anticoagulation effect of dabigatran is required, have not been established in paediatric patients. Haemodialysis can remove dabigatran. For adult patients, fresh whole blood or fresh frozen plasma, coagulation factor concentration (activated or non-activated), recombinant factor VIIa or platelet concentrates are other possible options (see also section 4.9).
Use of platelet aggregation inhibitors such as clopidogrel and acetylsalicylic acid (ASA) or non steroidal antiinflammatory drugs (NSAID), as well as the presence of esophagitis, gastritis or gastroesophageal reflux increase the risk of GI bleeding.
Risk factors
Table 3 summarises factors which may increase the haemorrhagic risk.
Table 3: Risk factors which may increase the haemorrhagic risk.
| | Risk factor |
| Factors increasing dabigatran plasma levels | Major: • Strong P-gp inhibitors (see section 4.3 and 4.5) • Mild to moderate P-gp inhibitor co-medication (e.g. amiodarone, verapamil, quinidine and ticagrelor; see section 4.5) |
| Pharmacodynamic interactions (see section 4.5) | • ASA and other platelet aggregation inhibitors such as clopidogrel • NSAIDs • SSRIs or SNRIs • Other medicinal products which may impair haemostasis |
| Diseases / procedures with special haemorrhagic risks | • Congenital or acquired coagulation disorders • Thrombocytopenia or functional platelet defects • Recent biopsy, major trauma • Bacterial endocarditis • Esophagitis, gastritis or gastroesophageal reflux |
The concomitant use of dabigatran etexilate with P-gp-inhibitors has not been studied in paediatric patients but may increase the risk of bleeding (see section 4.5).
Precautions and management of the haemorrhagic risk
For the management of bleeding complications, see also section 4.9.
Benefit-risk assessment
The presence of lesions, conditions, procedures and/or pharmacological treatment (such as NSAIDs, antiplatelets, SSRIs and SNRIs, see section 4.5), which significantly increase the risk of major bleeding requires a careful benefit-risk assessment. Dabigatran etexilate should only be given if the benefit outweighs bleeding risks.
Limited clinical data are available for paediatric patients with risk factors, including patients with active meningitis, encephalitis and intracranial abscess (see section 5.1). In these patients, dabigatran etexilate should only be given if the expected benefit outweighs bleeding risks.
Close clinical surveillance
Close observation for signs of bleeding or anaemia is recommended throughout the treatment period, especially if risk factors are combined (see table 3 above). Particular caution should be exercised when dabigatran etexilate is co-administered with verapamil, amiodarone, quinidine or clarithromycin (P-gp inhibitors) and particularly in the occurrence of bleeding, notably in patients having a reduced renal function (see section 4.5).
Close observation for signs of bleeding is recommended in patients concomitantly treated with NSAIDs (see section 4.5).
Discontinuation of dabigatran etexilate
Patients who develop acute renal failure must discontinue dabigatran etexilate.
When severe bleedings occur, treatment must be discontinued and the source of bleeding investigated. The efficacy and safety of the specific reversal agent (idarucizumab) to dabigatran have not been established in paediatric patients. Haemodialysis can remove dabigatran.
Laboratory coagulation parameters
Although this medicinal product does not in general require routine anticoagulant monitoring, the measurement of dabigatran related anticoagulation may be helpful to detect excessive high exposure to dabigatran in the presence of additional risk factors.
Diluted thrombin time (dTT), ecarin clotting time (ECT) and activated partial thromboplastin time (aPTT) may provide useful information, but results should be interpreted with caution due to inter-test variability (see section 5.1).
The international normalised ratio (INR) test is unreliable in patients on dabigatran etexilate and false positive INR elevations have been reported. Therefore, INR tests should not be performed.
Coagulation test thresholds at trough for paediatric patients that may be associated with an increased risk of bleeding are not known.
Use of fibrinolytic medicinal products for the treatment of acute ischemic stroke
The use of fibrinolytic medicinal products for the treatment of acute ischemic stroke may be considered if the patient presents with a dTT, ECT or aPTT not exceeding the upper limit of normal (ULN) according to the local reference range.
Surgery and interventions
Patients on dabigatran etexilate who undergo surgery or invasive procedures are at increased risk for bleeding. Therefore, surgical interventions may require the temporary discontinuation of dabigatran etexilate.
Caution should be exercised when treatment is temporarily discontinued for interventions and anticoagulant monitoring is warranted. Clearance of dabigatran in patients with renal insufficiency may take longer (see section 5.2). This should be considered in advance of any procedures. In such cases a coagulation test (see sections 4.4 and 5.1) may help to determine whether haemostasis is still impaired.
Emergency surgery or urgent procedures
Dabigatran etexilate should be temporarily discontinued.
The efficacy and safety of the specific reversal agent (idarucizumab) to dabigatran have not been established in paediatric patients. Haemodialysis can remove dabigatran.
Subacute surgery/interventions
Dabigatran etexilate should be temporarily discontinued. A surgery / intervention should be delayed if possible until at least 12 hours after the last dose. If surgery cannot be delayed the risk of bleeding may be increased. This risk of bleeding should be weighed against the urgency of intervention.
Elective surgery
If possible, dabigatran etexilate should be discontinued at least 24 hours before invasive or surgical procedures. In patients at higher risk of bleeding or in major surgery where complete haemostasis may be required consider stopping dabigatran etexilate 2-4 days before surgery.
Discontinuation rules before invasive or surgical procedures for paediatric patients are summarised in table 4.
Table 4: Discontinuation rules before invasive or surgical procedures for paediatric patients
| Renal function (eGFR in mL/min/1.73 m2) | Stop dabigatran before elective surgery |
| > 80 | 24 hours before |
| 50 - 80 | 2 days before |
| < 50 | These patients have not been studied (see section 4.3). |
Spinal anaesthesia/epidural anaesthesia/lumbar puncture
Procedures such as spinal anaesthesia may require complete haemostatic function.
The risk of spinal or epidural haematoma may be increased in cases of traumatic or repeated puncture and by the prolonged use of epidural catheters. After removal of a catheter, an interval of at least 2 hours should elapse before the administration of the first dose of dabigatran etexilate. These patients require frequent observation for neurological signs and symptoms of spinal or epidural haematoma.
Postoperative phase
Dabigatran etexilate treatment should be resumed / started after the invasive procedure or surgical intervention as soon as possible provided the clinical situation allows and adequate haemostasis has been established.
Patients at risk for bleeding or patients at risk of overexposure (see table 3) should be treated with caution (see sections 4.4 and 5.1).
Patients at high surgical mortality risk and with intrinsic risk factors for thromboembolic events
There are limited efficacy and safety data for dabigatran etexilate available in these patients and therefore they should be treated with caution.
Hepatic impairment
Patients with elevated liver enzymes > 2 ULN were excluded in the main trials. No treatment experience is available for this subpopulation of patients, and therefore the use of dabigatran etexilate is not recommended in this population. Hepatic impairment or liver disease expected to have any impact on survival is contraindicated (see section 4.3).
Interaction with P-gp inducers
Concomitant administration of P-gp inducers is expected to result in decreased dabigatran plasma concentrations, and should be avoided (see sections 4.5 and 5.2).
Patients with antiphospholipid syndrome
Direct acting Oral Anticoagulants (DOACs) including dabigatran etexilate are not recommended for patients with a history of thrombosis who are diagnosed with antiphospholipid syndrome. In particular for patients that are triple positive (for lupus anticoagulant, anticardiolipin antibodies, and anti–beta 2-glycoprotein I antibodies), treatment with DOACs could be associated with increased rates of recurrent thrombotic events compared with vitamin K antagonist therapy.
Active cancer patients
There is limited data on efficacy and safety for paediatric patients with active cancer.
Very specific paediatric population
For some very specific paediatric patients, e.g. patients with small bowel disease where absorption may be affected, use of an anticoagulant with parenteral route of administration should be considered.