Description
Dabigatran etexilate mesylate is a clinical direct thrombin inhibitor and a new type of oral anticoagulant. It can inhibit the formation of thrombus by reversibly and potently competing with the fibrin-specific binding site of thrombin to block fibrin generation.
Chemical Properties
Off-White to Pale Yellow Solid
History
Dabigatran Etexilate Mesylate (brand name pradaxa) was discovered from a panel of chemicals with similar structure to benzamidine-based thrombin inhibitor α-NAPAP (N-alpha-(2-naphthylsulfonylglycyl)-4-amidinophenylalanine piperidide). Addition of ethyl ester and hexyloxycarbonyl carbamide hydrophobic side chains led to the orally absorbed prodrug, BIBR 1048 (dabigatran etexilate).
In March 2008, the European Medicines Agency (EMA) granted marketing authorization for Pradaxa for the prevention of thromboembolic disease following hip or knee replacement surgery and for non-valvular atrial fibrillation.
The National Health Service (NHS) in Britain authorized dabigatran for use in preventing blood clots in hip and knee replacement surgery patients.
Pradaxa received a Notice of Compliance (NOC) from Health Canada in June 2008,[45] for the prevention of blood clots in patients who have undergone total hip or total knee replacement surgery. Approval for atrial fibrillation patients at risk of stroke came in October 2010.
The U.S. Food and Drug Administration (FDA) approved Pradaxa in October 2010, for prevention of stroke in patients with non-valvular atrial fibrillation.
In February 2011, the American College of Cardiology Foundation and the American Heart Association added dabigatran to their guidelines for management of non-valvular atrial fibrillation with a class I recommendation.
Uses
Nonpeptide, direct thrombin inhibitor. Antithrombotic.
Clinical Use
Dabigatran Etexilate Mesylate is a direct thrombin inhibitor indicated to reduce the risk of stroke and systemic embolism in patients with nonvalvular atrial fibrillation.
Definition
ChEBI: A methanesulfonate salt obtained by reaction of dabigatran etexilate with one equivalent of dabigatran etexilate. A prodrug for dabigatran, a thrombin inhibitor and anticoagulant which is used for the prevention of stroke and systemic embolism.
Biological Activity
Dabigatran etexilate mesylate (BIBR 1048MS) is an orally active prodrug of Dabigatran. Dabigatran etexilate mesylate has anticoagulant properties and can prevent venous thromboembolism and stroke due to atrial fibrillation.
Mechanism of action
Dabigatran etexilate mesylate is a prodrug of dabigatran that is metabolized in the body and converted to the active dabigatran. Compared with warfarin, dabigatran etexilate mesylate does not require frequent monitoring of coagulation function and dose adjustment during treatment, and there are fewer interactions between drugs and is not affected by eating, thus improving patients' medication compliance.
Side effects
The most common adverse reactions to Dabigatran Etexilate Mesylate (150 mg) were bleeding and gastrointestinal events (i.e. dyspepsia, nausea, epigastric pain, gastrointestinal bleeding, and diarrhoea). Very few patients experienced drug hypersensitivity (including urticaria, rash and pruritus), anaphylactic oedema, anaphylactic reactions and anaphylaxis.
Synthesis
Using ethyl 3-(2-(((4-(N-((hexyloxy)carbonyl)carbamoyl)phenyl)amino)methyl)-1-methyl-N-(pyridin-2-yl)-1H-benzo[d]imidazole-5-carboxamido)propanoate (52.6 kg, recommended to be pre-purified by recrystallization from ethyl acetate) and methanesulfonic acid as the raw material, the following steps were carried out:
1. add pre-purified ethyl 3-(2-(((4-(N-((hexyloxy)carbonyl)carbamoyl)phenyl)amino)methyl)-1-methyl-N-(pyridin-2-yl)-1H-benzo[d]imidazole-5-carboxamido)propionate to an inerted stirring apparatus.
2. 293 kg of acetone is added, stirred and heated to 40 °C to 46 °C until a clarified solution is formed.
3. the solution was filtered through a lens filter into a second stirring device and subsequently cooled to 30°C to 36°C.
4. in another vessel, 33 kg of acetone was pre-cooled to 0 °C to 5 °C, 7.9 kg of 99.5% methanesulfonic acid and 9 kg of acetone were added and mixed well.
5. The methanesulfonic acid solution was added stoichiometrically over 15 to 40 minutes to a solution of ethyl 3-(2-(((4-(N-((hexyloxy)carbonyl)carbamoyl)phenyl)amino)methyl)-1-methyl-N-(pyridin-2-yl)-1H-benzo[d]imidazole-5-carboxamido)propionate in a second apparatus, maintained at a temperature of 26° C. to 36° C. The ethyl 3-(2-(((4-(N-(hexyloxy)carbonyl)carbamoyl)phenyl)amino)methyl)-1-methyl-N-(pyridin-2-yl)-1H-benz[d]imidazole-5-carboxamide)propionate solution was added in a second apparatus, maintained at a temperature of 26° C. to 36° C.
6. After addition, stirring was continued at 26°C to 33°C for 40 to 60 minutes.
7. the mixture was cooled to 17°C to 23°C and stirred for an additional 40 to 80 minutes.
8. The crystal suspension was filtered and washed with a total of 270 L of acetone.
9. The product was dried under vacuum at not more than 50 °C for at least 4 hours.
Yield: 54.5-59.4 kg, based on a theoretical yield of 90%-98% for ethyl 3-(2-(((4-(N-((hexyloxy)carbonyl)carbamoyl)phenyl)amino)methyl)-1-methyl-N-(pyridin-2-yl)-1H-benzo[d]imidazole-5-carboxamido)propanoate.
in vivo
Dabigatran etexilate mesylate (BIBR 1048MS; oral; 10, 20 and 50 mg/kg for rats and 1, 2.5 and 5 mg/kg for monkeys) has dose- and time-dependent anticoagulant effects and has maximum effects between 30 and 120 min after administration, respectively.Dabigatran etexilate mesylate maximally and significantly prolongs partial thromboplastin time (aPTT) to 25.2, 38.4 and 78.3 s in 30 min after 10, 20 and 50 mg/kg oral doses, respectively.Dabigatran etexilate mesylate maximally prolongs the aPTT to 34.3 s, 44.0 s, and 63.0 s, respectively, 2h after 1, 2.5 or 5 mg/kg doses in the monkey.
References
[1] Patent: WO2012/44595, 2012, A1. Location in patent: Page/Page column 15
[2] Patent: WO2014/192030, 2014, A2. Location in patent: Page/Page column 26
