Direct thrombin inhibitors are a class of drugs that function as anticoagulants. Anticoagulants are drugs that delay the onset of clotting. These drugs are used in the treatment of conditions such as deep vein thrombosis, stroke, heart attack, and heparin-induced thrombocytopenia. There are three main classes of DTI in use: bivalent, univalent, and allosteric. Current research is focusing on allosteric DTIs, as it is thought that these offer the best prospects for patients with the aforementioned vascular conditions. The most common side-effect for DTIs is bleeding, as the body cannot clot the blood as quickly as usual. Should the bleeding become too severe, a coagulant such as phytomenadione (Vitamin K1) is typically administered. There are numerous significant clinical interactions with direct thrombin inhibitors, most of which increase the anticoagulant effect, thereby increasing the risk of bleeding.
Direct Thrombin Inhibitor Drugs
Below you will find drugs that are classified as direct thrombin inhibitors. Bivalent direct thrombin inhibitors
Univalent direct thrombin inhibitors
Direct Thrombin Inhibitor Uses
The main drug of the bivalent class, bivalirudin, is a synthetic version of hirudin. Hirudin was found in the saliva of leeches, as leeches require anticoagulation if they intend to consume blood from their prey. Synthetic drugs like bivalirudin were then developed based on the structure of hirudin. The main use of bivalirudin is in the treatment of patients undergoing PCI, or percutaneous coronary intervention. This procedure involves the placement of a stent in the coronary arteries in patients who have had a heart attack. Bivalirudin ensures that no clot formation will result during the procedure, keeping the blood at a suitable level of anticoagulation.
The main drug of the univalent class, dabigatran, is used as a prophylactic in patients who have atrial fibrillation and may be at the risk of a stroke. Additionally, dabigatran is employed in conditions such as deep vein thrombosis and pulmonary embolism. One of the chief difficulties with dabigatran is that if a major bleeding event should occur, it is very hard to stop. Unlike drugs such as warfarin where this reversal is possible, dabigatran does not respond to reversal, thereby making it more challenging for physicians to deal with such a complication.
Direct Thrombin Inhibitor Side Effects
Typical side-effects of direct thrombin inhibitors include bleeding, fever, and pain. Below some of the common side effects are listed.
- Abdominal pain
- Back pain
If you experience severe blood loss while using a direct thrombin inhibitor, immediately contact your physician.
Direct Thrombin Inhibitor Interactions
Direct thrombin inhibitors interact with drugs that may increase the risk of further anticoagulation. As a result, these drugs interact with other anticoagulants, including aspirin, to increase the risk of bleeding. Given that vitamin K is directly involved in the clotting process, eating vitamin K-rich foods such as green leafy vegetables may have a reversing effect on that of the DTIs. Broad-spectrum antibiotics may eliminate vitamin K-producing bacteria in the gut and, consequently, increase the risk of bleeding if taken with DTIs.