Is there any literature supporting starting Pradaxa (dabigatran) without parenteral anticoagulation OR with less than 5 days of parenteral anticoagulation lead-in?

Comment by InpharmD Researcher

Limited literature supports initiating dabigatran after fewer than 5 days of parenteral anticoagulation, while no efficacy or safety data were identified for initiating dabigatran without a parenteral anticoagulant lead-in. In the single-arm PEITHO-2 trial, 402 patients with acute intermediate-risk pulmonary embolism received parenteral anticoagulation for 72 hours followed by dabigatran, with recurrent symptomatic venous thromboembolism or pulmonary embolism-related death occurring in 7 patients (2%) and major bleeding in 11 patients (3%) within 6 months. A retrospective review documented that 5 of 6 patients treated for pulmonary embolism did not receive the recommended 5 to 10 days of parenteral anticoagulation before dabigatran; however, the duration of lead-in and outcomes for these patients were not reported. Notably, the pivotal dabigatran trials used at least 5 days of initial parenteral anticoagulation, and prescribing information specifies dabigatran initiation after 5 to 10 days of parenteral anticoagulation for the treatment of deep vein thrombosis and pulmonary embolism.
Background

In early clinical trials of edoxaban and dabigatran, initial treatment consisted of open-label parenteral anticoagulation (minimum of 5 days) overlapped with warfarin titrated to an INR of 2-3 in the control arm or overlapped with warfarin-placebo titrated to a sham INR in the intervention arms. None of these studies gave concomitant parenteral anticoagulation plus direct oral anticoagulation (DOAC), as that would lead to excessive anticoagulation and increased bleeding risk. By contrast apixaban and rivaroxaban landmark trials for venous thromboembolism (VTE) treatment allowed optional parenteral anticoagulation for a maximum of 36-48 hours. In these studies, patients generally received less than 1 day of parenteral anticoagulation before switching to the DOAC. Additionally, apixaban and rivaroxaban have a loading period before switching to maintenance dosing; dabigatran and edoxaban do not have a loading period. The reasons for these differences are unknown and may be due to pharmacokinetics or potential safety concerns when these were new, untested agents during the acute phase of VTE when patients are most at risk for VTE recurrence or clot extension (i.e, the first 5-7 days after VTE index event). [1], [2], [3], [4]

Background References: [1] Burnett AE, Mahan CE, Vazquez SR, Oertel LB, Garcia DA, Ansell J. Guidance for the practical management of the direct oral anticoagulants (DOACs) in VTE treatment. J Thromb Thrombolysis. 2016;41(1):206-232. doi:10.1007/s11239-015-1310-7
[2] Dobesh PP, Fanikos J. New oral anticoagulants for the treatment of venous thromboembolism: understanding differences and similarities. Drugs. 2014;74(17):2015-2032. doi:10.1007/s40265-014-0301-x
[3] Chen A, Stecker E, A Warden B. Direct Oral Anticoagulant Use: A Practical Guide to Common Clinical Challenges. J Am Heart Assoc. 2020;9(13):e017559. doi:10.1161/JAHA.120.017559
[4] Hillis C, Crowther MA. Acute phase treatment of VTE: Anticoagulation, including non-vitamin K antagonist oral anticoagulants [published correction appears in Thromb Haemost. 2015 Jul;114(1):210]. Thromb Haemost. 2015;113(6):1193-1202. doi:10.1160/TH14-12-1036
Relevant Prescribing Information

INDICATIONS AND USAGE [5]
Treatment of Deep Venous Thrombosis and Pulmonary Embolism in Adult Patients
PRADAXA Capsules is indicated for the treatment of deep venous thrombosis and pulmonary embolism in adult patients who have been treated with a parenteral anticoagulant for 5-10 days.

DOSAGE AND ADMINISTRATION [5]
Recommended PRADAXA Capsules Dosage for Adults
For patients with CrCl > 30 mL/min, the recommended dosage of PRADAXA Capsules is 150 mg taken orally, twice daily, after 5-10 days of parenteral anticoagulation. Dosing recommendations for patients with a CrCl ≤ 30 mL/min or on dialysis cannot be provided

Relevant Prescribing Information References: [5] Pradaxa (dabigatran etexilate mesylate capsule). Prescribing Information. Boehringer Ingelheim Pharmaceuticals Inc.; 2025.
Literature Review

A search of the published medical literature revealed 2 studies investigating the researchable question:

Is there any literature supporting starting Pradaxa (dabigatran) without parenteral anticoagulation OR with less than 5 days of parenteral anticoagulation lead-in?

Level of evidence

C - Multiple studies with limitations or conflicting results  Read more→



Please see Tables 1-2 for your response.


Early Switch to Oral Anticoagulation in Patients with Acute Intermediate-Risk Pulmonary Embolism (PEITHO-2): A Multinational, Multicentre, Single-arm, Phase 4 Trial
Design

Multinational, multicentre, single-arm, phase 4 trial

N= 402

Objective

To ascertain whether treatment of acute intermediate-risk pulmonary embolism with parenteral anticoagulation for a short period of 72 h followed by treatment with the direct oral anticoagulant (DOAC), dabigatran, for 6 months is effective and safe

Study Groups

All patients (n= 402)

Inclusion Criteria

Adult patients (aged ≥18 years) with symptomatic intermediate-risk pulmonary embolism, with or without deep-vein thrombosis, confirmed by CT pulmonary angiography, a ventilation or perfusion lung scan, or selective invasive pulmonary angiography

Exclusion Criteria

Indication for long-term anticoagulation treatment other than the index pulmonary embolism episode; contraindications to dabigatran; active bleeding or risk of clinically significant bleeding; creatinine clearance <30 mL/min; severe chronic liver disease; pregnancy or lactation; use of fibrinolytic agent, surgical thrombectomy, or cava filter; treatment with anticoagulant for more than 48 h before enrolment; artificial heart valves; strong inhibitors of p-glycoprotein; medical or psychological condition preventing trial completion; participation in another clinical trial within the last 3 months; life expectancy <6 months

Methods

Patients received parenteral low-molecular-weight or unfractionated heparin for 72 h after diagnosis of pulmonary embolism before switching to oral dabigatran 150 mg twice per day following a standard clinical assessment. The primary and safety outcomes were assessed in the intention-to-treat population.

Duration

January 1, 2016, to July 31, 2019

Outcome Measures

Primary: Recurrent symptomatic venous thromboembolism or pulmonary embolism-related death within 6 months

Secondary: Pulmonary embolism-related and all-cause death, hemodynamic collapse or decompensation within 30 days, death from any cause within 6 months, duration of unscheduled hospital stay due to complications or bleeding within 6 months

Baseline Characteristics

 

All patients (n= 402)

Age, years, median (IQR)

69.5 (60.0 to 78.0)

>80 years

67 (17%)

Female

192 (48%)

Major trauma in the past 30 days

13 (3%)

Major surgery in the past 30 days

14 (3%)

Immobilisation (for at least 3 days)

52 (13%)

Previous pulmonary embolism or deep vein thrombosis

107 (27%)

Active cancer

10 (2%)

History of cancer

38 (9%)

Ongoing chemotherapy

3 (<1%)

History of chronic cardiopulmonary disease

83 (21%)

BMI, kg/m², median (IQR)

28.05 (25.05 to 31.82)

Heart rate, BPM, median (IQR)

84 (72 to 97)

Heart rate >100 beats per minute

40 (10%)

Systolic/diastolic blood pressure, mm Hg, median (IQR)

130 (119 to 140)/76 (70 to 82)

Systolic blood pressure <100 mm Hg

7 (2%)

Oxygen saturation <90%

27/399 (7%)

Simplified Pulmonary Embolism Severity Index ≥1

213 (53%)

Signs of right ventricular dysfunction on at least one imaging method

371/377 (98%)

Signs of right ventricular dysfunction on echocardiography

338/350 (97%)

Signs of right ventricular dysfunction on CT pulmonary angiography

202/248 (81%)

Elevated cardiac troponin concentrations

308/382 (81%)

Abbreviations: IQR, interquartile range; BMI, body mass index; BPM, beats per minute

Results

 

All patients (n= 402)

Recurrent symptomatic venous thromboembolism or death related to pulmonary embolism within the first 6 months

7 (2%; 3)

Recurrent pulmonary embolism

5 (1%)

Recurrent deep-vein thrombosis

3 (<1%)

Death related to pulmonary embolism

2 (<1%)

Pulmonary embolism-related death, hemodynamic collapse, or hemodynamic decompensation within the first 30 days

3 (<1%)

Death from any cause, hemodynamic collapse, or decompensation within the first 30 days

5 (1%)

Death from any cause within the first 6 months

8 (2%)

At least one major bleeding event within 6 months

11 (3%; 1 to 5)

At least one clinically relevant non-major bleeding within 6 months

16 (4%; 2 to 6)

At least one major or clinically relevant non-major bleeding event within 6 months

26 (7%; 4 to 9)

At least one serious adverse event within 30 days

34 (9%)

At least one serious adverse event within 6 months

71 (18%)

Data are n (%; upper bound of right-sided 95% confidence interval [CI]), n (%), or n (%; 95% CI)

Adverse Events

At least one major bleeding event within 6 months (3%); at least one clinically relevant non-major bleeding within 6 months (4%); at least one major or clinically relevant non-major bleeding event within 6 months (7%); at least one serious adverse event within 30 days (9%); at least one serious adverse event within 6 months (18%)

Study Author Conclusions

In conclusion, this prospective multinational trial focusing on patients with intermediate-risk pulmonary embolism found that a management strategy of early switch from heparin to dabigatran after rigorous clinical assessment of stabilisation at 72 h was both effective and safe. Our results help to close existing gaps in the evidence base concerning the initial treatment of patients who have an elevated risk of early complications with anticoagulants. They also support the clinical relevance of identifying patients with intermediate-high-risk pulmonary embolism, presenting with signs of both right ventricular dysfunction and with elevated cardiac troponin concentrations, because this patient group might need closer early monitoring and long-term follow-up to prevent a complex disease course than those with intermediate-low-risk and low-risk pulmonary embolism. The knowledge obtained from the PEITHO-2 study aids in refining future recommendations on the risk-adjusted management of acute pulmonary embolism.

Critique

The study provided valuable insights into the management of intermediate-risk pulmonary embolism with a novel anticoagulation strategy. However, the lack of a control group receiving standard care limits the ability to directly compare outcomes. The study's single-arm design and the absence of randomisation may introduce bias. Additionally, the study's focus on dabigatran limits the generalisability of the findings to other DOACs. Despite these limitations, the study's rigorous selection criteria and multicentre design enhance the applicability of the findings to clinical practice.

Table 1 References:
[6] Klok FA, Toenges G, Mavromanoli AC, et al. Early switch to oral anticoagulation in patients with acute intermediate-risk pulmonary embolism (PEITHO-2): a multinational, multicentre, single-arm, phase 4 trial. Lancet Haematol. 2021;8(9):e627-e636. doi:10.1016/S2352-3026(21)00203-9

Evaluation of Dabigatran for Appropriateness of Use and Bleeding Events in a Community Hospital Setting

Design

Retrospective chart review

N= 458

Objective

To describe and to evaluate the use of dabigatran at a community hospital to identify areas for improvement in its prescribing

Study Groups

All patients (n= 458)

Inclusion Criteria

Patients who received at least 1 dose of dabigatran between December 2010 and June 2012

Exclusion Criteria

Patients without available data on serum creatinine, height, or weight

Methods

Eligible patients were identified through the hospital pharmacy information system. Baseline demographic and clinical data were collected, including age, sex, race, length of stay, height, weight, serum creatinine, creatinine clearance at dabigatran initiation, indication for dabigatran, outpatient anticoagulant use, concomitant antithrombotic therapy, and potentially interacting medications. Appropriateness of the initial dabigatran regimen was evaluated according to FDA-approved recommendations for stroke prophylaxis in nonvalvular atrial fibrillation based on valvular disease, dose, and dosing frequency; patients receiving dabigatran for off-label indications, including venous thromboembolism (VTE) and pulmonary embolism (PE), were not evaluated for regimen appropriateness. For the inquiry-specific analysis, the investigators identified 6 patients treated for PE and determined whether they had received the recommended 5 to 10 days of parenteral anticoagulation before dabigatran initiation. Bleeding was assessed using hospital readmission within 1 year for bleeding, a hemoglobin decrease of ≥2 g/dL, transfusion of ≥2 units of blood, or documentation of bleeding in the medical record. Descriptive statistics characterized prescribing patterns; bleeding and nonbleeding groups were compared using the Student t test, chi-square test, or Fisher exact test, as applicable.

Duration

December 2010 to June 2012

Outcome Measures

Primary: Appropriateness of dabigatran use

Secondary: Composite endpoint of bleeding including hospital readmission, hemoglobin decrease, blood transfusion, or bleeding notation

Baseline Characteristics  

All patients (n= 458)

Mean age, years

73 ± 13.1

Male 

247 (54%)

Race

Caucasian

Black

 

419 (91.5%)

18 (3.9%)

Mean length of hospital stay, days

4.9 ± 5.3

Mean body mass index, kg/m2 (median)

29.9 ± 7.32 (29)

Mean weight, kg (median)

88.5 ± 26 (85)

Weight <50 kg

12 (2.6%)

Weight >100 kg

124 (27.1%)

Indication for dabigatran

Atrial fibrillation

VTE 

 

426 (93%)

18 (3.9%)

Results

 

Patients (n= 458)

Inappropriate regimen

76 (16.6%)

Home medication inappropriately continued

41 (9%)

Medication inappropriately initiated in hospital

35 (7.6%)

Contraindicated due to renal function

8 (1.7%)

Inappropriate dose

66 (14.4%)

Inappropriate frequency

13 (2.8%)

Bioprosthetic valve

12 (2.6%)

Moderate or severe mitral stenosis

1 (0.2%)
Adverse Events

The composite endpoint for bleeding was reported in 66 (14.4%) patients, including 23 (5%) with confirmed gastrointestinal bleeding.

Study Author Conclusions

High-risk medications such as dabigatran require monitoring of prescribing habits to improve patient safety and outcomes. Various initiatives, such as pharmacist interventions, therapeutic interchanges, and obtaining appropriate patient parameters, can be implemented in the practice setting to ensure the appropriate use of oral anticoagulants and improved patient outcomes.

Critique

This study documents real-world dabigatran initiation without the recommended 5- to 10-day parenteral anticoagulation course in 5 of 6 patients treated for PE. However, it does not distinguish between no lead-in and a lead-in lasting fewer than 5 days or report thromboembolic and bleeding outcomes for these patients separately; therefore, it demonstrates that this prescribing practice occurred but does not provide evidence supporting its efficacy or safety.

Table 2 References:
[7] Armbruster AL, Buehler KS, Min SH, Riley M, Daly MW. Evaluation of dabigatran for appropriateness of use and bleeding events in a community hospital setting. Am Health Drug Benefits. 2014;7(7):376-384.