Interactions : אינטראקציות

4.5   Interaction with other medicinal products and other forms of interaction

Transporter interactions

Dabigatran etexilate is a substrate for the efflux transporter P-gp. Concomitant administration of P-gp inhibitors (see table 7) is expected to result in increased dabigatran plasma concentrations.

If not otherwise specifically described, close clinical surveillance (looking for signs of bleeding or anaemia) is required when dabigatran is co-administered with strong P-gp inhibitors. Dose reductions may be required in combination with some P-gp inhibitors (see sections 4.2, 4.3, 4.4 and 5.1).

Table 7: Transporter interactions

P-gp inhibitors


Concomitant use contraindicated (see section 4.3)
Ketoconazole      Ketoconazole increased total dabigatran AUC0-∞ and Cmax values by 2.38-fold and                    2.35-fold, respectively, after a single oral dose of 400 mg, and by 2.53-fold and
2.49-fold, respectively, after multiple oral dosing of 400 mg ketoconazole once daily.
Dronedarone       When dabigatran etexilate and dronedarone were given at the same time total dabigatran AUC0-∞ and Cmax values increased by about 2.4-fold and 2.3-fold, respectively, after multiple dosing of 400 mg dronedarone bid, and about 2.1-fold and 1.9-fold, respectively, after a single dose of 400 mg.
Itraconazole,     Based on in vitro results a similar effect as with ketoconazole may be expected.
cyclosporine
Glecaprevir /     The concomitant use of dabigatran etexilate with the fixed-dose combination of the pibrentasvir      P-gp inhibitors glecaprevir/pibrentasvir has been shown to increase exposure of dabigatran and may increase the risk of bleeding.

Concomitant use not recommended

Tacrolimus        Tacrolimus has been found in vitro to have a similar level of inhibitory effect on P- gp as that seen with itraconazole and cyclosporine. Dabigatran etexilate has not been clinically studied together with tacrolimus. However, limited clinical data with another P-gp substrate (everolimus) suggest that the inhibition of P-gp with tacrolimus is weaker than that observed with strong P-gp inhibitors.

Cautions to be exercised in case concomitant use (see sections 4.2 and 4.4) 
Verapamil          When dabigatran etexilate (150 mg) was co-administered with oral verapamil, the Cmax and AUC of dabigatran were increased but the magnitude of this change differs depending on timing of administration and formulation of verapamil (see sections 4.2 and 4.4).

The greatest elevation of dabigatran exposure was observed with the first dose of an immediate release formulation of verapamil administered one hour prior to the Pradaxa 110                                                                    Prescribing Information Boehringer Ingelheim                                                                      January 2022 dabigatran etexilate intake (increase of Cmax by about 2.8-fold and AUC by about                  2.5-fold). The effect was progressively decreased with administration of an extended release formulation (increase of Cmax by about 1.9-fold and AUC by about 1.7-fold) or administration of multiple doses of verapamil (increase of Cmax by about 1.6-fold and AUC by about 1.5-fold).

There was no meaningful interaction observed when verapamil was given 2 hours after dabigatran etexilate (increase of Cmax by about 1.1-fold and AUC by about 1.2-fold). This is explained by completed dabigatran absorption after 2 hours.
Amiodarone       When dabigatran etexilate was co-administered with a single oral dose of 600 mg amiodarone, the extent and rate of absorption of amiodarone and its active metabolite DEA were essentially unchanged. The dabigatran AUC and Cmax were increased by about 1.6-fold and 1.5-fold, respectively. In view of the long half-life of amiodarone the potential for an interaction may exist for weeks after discontinuation of amiodarone (see sections 4.2 and 4.4).
Quinidine        Quinidine was given as 200 mg dose every 2nd hour up to a total dose of 1,000 mg.
Dabigatran etexilate was given twice daily over 3 consecutive days, on the 3rd day either with or without quinidine. Dabigatran AUCτ,ss and Cmax,ss were increased on average by 1.53-fold and 1.56-fold, respectively with concomitant quinidine (see sections 4.2 and 4.4).
Clarithromycin   When clarithromycin (500 mg twice daily) was administered together with dabigatran etexilate in healthy volunteers, increase of AUC by about 1.19-fold and Cmax by about 1.15-fold was observed.
Ticagrelor       When a single dose of 75 mg dabigatran etexilate was coadministered simultaneously with a loading dose of 180 mg ticagrelor, the dabigatran AUC and Cmax were increased by 1.73-fold and 1.95-fold, respectively. After multiple doses of ticagrelor 90 mg b.i.d. the increase of dabigatran exposure is 1.56-fold and 1.46- fold for Cmax and AUC, respectively.

Concomitant administration of a loading dose of 180 mg ticagrelor and 110 mg dabigatran etexilate (in steady state) increased the dabigatran AUCτ,ss and Cmax,ss by 1.49-fold and 1.65-fold, respectively, compared with dabigatran etexilate given alone. When a loading dose of 180 mg ticagrelor was given 2 hours after 110 mg dabigatran etexilate (in steady state), the increase of dabigatran AUCτ,ss and Cmax,ss was reduced to 1.27-fold and 1.23-fold, respectively, compared with dabigatran etexilate given alone. This staggered intake is the recommended administration for start of ticagrelor with a loading dose.

Concomitant administration of 90 mg ticagrelor b.i.d. (maintenance dose) with 110 mg dabigatran etexilate increased the adjusted dabigatran AUCτ,ss and Cmax,ss 1.26-fold and 1.29-fold, respectively, compared with dabigatran etexilate given alone.
Posaconazole     Posaconazole also inhibits P-gp to some extent but has not been clinically studied.
Caution should be exercised when dabigatran etexilate is co-administered with posaconazole.

P-gp inducers

Pradaxa 110                                                                        Prescribing Information Boehringer Ingelheim                                                                          January 2022 
Concomitant use should be avoided.
 e.g. rifampicin,    Concomitant administration is expected to result in decreased dabigatran St. John´s wort     concentrations.
(Hypericum perforatum),        Pre-dosing of the probe inducer rifampicin at a dose of 600 mg once daily for carbamazepine,      7 days decreased total dabigatran peak and total exposure by 65.5% and 67%, or phenytoin        respectively. The inducing effect was diminished resulting in dabigatran exposure close to the reference by day 7 after cessation of rifampicin treatment. No further increase in bioavailability was observed after another 7 days.

Protease inhibitors such as ritonavir

Concomitant use not recommended
 e.g. ritonavir      These affect P-gp (either as inhibitor or as inducer). They have not been studied and and its             are therefore not recommended for concomitant treatment with dabigatran etexilate.
combinations with other protease inhibitors

P-gp substrate

Digoxin             In a study performed with 24 healthy subjects, when dabigatran etexilate was co-administered with digoxin, no changes on digoxin and no clinically relevant changes on dabigatran exposure have been observed.

Anticoagulants and antiplatelet aggregation medicinal products

There is no or only limited experience with the following treatments which may increase the risk of bleeding when used concomitantly with dabigatran etexilate: anticoagulants such as unfractionated heparin (UFH), low molecular weight heparins (LMWH), and heparin derivatives (fondaparinux, desirudin), thrombolytic medicinal products, and vitamin K antagonists, rivaroxaban or other oral anticoagulants (see section 4.3), and antiplatelet aggregation medicinal products such as GPIIb/IIIa receptor antagonists, ticlopidine, prasugrel, ticagrelor, dextran, and sulfinpyrazone (see section 4.4).

From the data collected in the phase III study RE-LY (see section 5.1) it was observed that the concomitant use of other oral or parenteral anticoagulants increases major bleeding rates with both dabigatran etexilate and warfarin by approximately 2.5-fold, mainly related to situations when switching from one anticoagulant to another (see section 4.3). Furthermore, concomitant use of antiplatelets, ASA or clopidogrel approximately doubled major bleeding rates with both dabigatran etexilate and warfarin (see section 4.4).

UFH can be administered at doses necessary to maintain a patent central venous or arterial catheter or during catheter ablation for atrial fibrillation (see section 4.3).


Pradaxa 110                                                                       Prescribing Information Boehringer Ingelheim                                                                         January 2022 Table 8: Interactions with anticoagulants and antiplatelet aggregation medicinal products 
NSAIDs      NSAIDs given for short-term analgesia have been shown not to be associated with increased bleeding risk when given in conjunction with dabigatran etexilate. With chronic use in the RE-LY study, NSAIDs increased the risk of bleeding by approximately 50% on both dabigatran etexilate and warfarin.
Clopidogrel In young healthy male volunteers, the concomitant administration of dabigatran etexilate and clopidogrel resulted in no further prolongation of capillary bleeding times compared to clopidogrel monotherapy. In addition, dabigatran AUCτ,ss and Cmax,ss and the coagulation measures for dabigatran effect or the inhibition of platelet aggregation as measure of clopidogrel effect remained essentially unchanged comparing combined treatment and the respective mono-treatments. With a loading dose of 300 mg or 600 mg clopidogrel, dabigatran AUCτ,ss and Cmax,ss were increased by about 30-40% (see section 4.4) .
ASA         Co-administration of ASA and 150 mg dabigatran etexilate twice daily may increase the risk for any bleeding from 12% to 18% and 24% with 81 mg and 325 mg ASA, respectively (see section 4.4).
LMWH        The concomitant use of LMWHs, such as enoxaparin and dabigatran etexilate has not been specifically investigated. After switching from 3-day treatment of once daily              40 mg enoxaparin s.c., 24 hours after the last dose of enoxaparin the exposure to dabigatran was slightly lower than that after administration of dabigatran etexilate (single dose of 220 mg) alone. A higher anti-FXa/FIIa activity was observed after dabigatran etexilate administration with enoxaparin pre-treatment compared to that after treatment with dabigatran etexilate alone. This is considered to be due to the carry-over effect of enoxaparin treatment, and regarded as not clinically relevant. Other dabigatran related anti-coagulation tests were not changed significantly by the pre-treatment of enoxaparin.

Other interactions

Table 9: Other interactions
Selective serotonin re-uptake inhibitors (SSRIs) or selective serotonin norepinephrine re-uptake inhibitors (SNRIs)

SSRIs, SNRIs        SSRIs and SNRIs increased the risk of bleeding in RE-LY in all treatment groups, 
Substances influencing gastric pH

Pantoprazole        When Pradaxa was co-administered with pantoprazole, a decrease in the dabigatran AUC of approximately 30% was observed. Pantoprazole and other proton-pump inhibitors (PPI) were co-administered with Pradaxa in clinical trials, and concomitant PPI treatment did not appear to reduce the efficacy of Pradaxa.
Ranitidine          Ranitidine administration together with dabigatran etexilate had no clinically relevant effect on the extent of absorption of dabigatran.

Interactions linked to dabigatran etexilate and dabigatran metabolic profile 

Pradaxa 110                                                                    Prescribing Information Boehringer Ingelheim                                                                        January 2022 Dabigatran etexilate and dabigatran are not metabolised by the cytochrome P450 system and have no in vitro effects on human cytochrome P450 enzymes. Therefore, related medicinal product interactions are not expected with dabigatran.


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