Hematinics
Anemia develops as a result of three main mechanisms: hemorrhage, hemolysis, and decreased erythrocyte production. Some causes of anemia can be treated pharmacologically by directly addressing the mechanisms of decreased erythrocyte production. For example, insufficient production of erythropoietic stimuli can be treated with erythropoiesis-stimulating agents such as epoetin alfa or darbepoetin. Similarly, deficiency of vitamins or minerals required for erythrocyte and hemoglobin synthesis can be reversed with their supplementation.
Hematinics are nutrients required for hematopoiesis. For specific drugs used to treat anemia that is due to decreased erythrocyte production, see the table Erythropoiesis-Stimulating Agents and Hematinics for Treatment of Anemia.
Hemostatics
Hemostatic agents, also known as antihemorrhagic agents, are substances that promote hemostasis or cessation of hemorrhage.
Hemostatics can be applied topically or administered systemically (see the table Topical and Systemic Hemostatic Agents). Topical hemostatics are applied most commonly for bleeding associated with invasive procedures or with minor, clean wounds.
For minor procedures such as toenail clipping, a topical hemostatic agent may be all that is needed to augment hemostasis and control bleeding. However, for surgical bleeding from a vascular organ, topical agents tend to be used in addition to other surgical hemostatic techniques, such as vessel ligation.
Most topical hemostatics are not specifically approved for veterinary use, and their application is supported predominantly by anecdotal reports rather than veterinary literature. In general, the smallest amount of hemostatic required to achieve hemostasis should be used.
Thromboprophylactics
Treatment with thromboprophylactic agents (see the table Drugs Used for Thromboprophylaxis) is indicated in documented thrombosis or in diseases associated with a high risk of thrombosis, such as immune-mediated hemolytic anemia (IMHA) in dogs; cardiomyopathy in cats; protein-losing nephropathy (PLN), particularly in dogs; and heartworm disease.
A variety of thromboprophylactic drugs are available for veterinary patients, including antiplatelet drugs and anticoagulants (anti–clotting factor drugs).
Antiplatelet drugs are first-line treatment for disease associated with arterial thrombosis (eg, cardiomyopathy in cats, PLN in dogs). Aspirin and, increasingly, clopidogrel are the most commonly used antiplatelet medications in veterinary medicine.
Anticoagulants are first-line treatment for diseases associated with venous thrombosis (eg, IMHA in dogs).
A combination of antiplatelet drugs and anticoagulants may be indicated in diseases associated with a high risk of thrombosis (eg. IMHA), where the potential benefits are thought to outweigh the risks (of bleeding) in the individual patient.
Direct orally administered anticoagulants, particularly rivaroxaban, as well as injectable anticoagulants (low-molecular-weight heparin and unfractionated heparins) are the most commonly used anticoagulants in veterinary medicine. In dogs, tissue plasminogen activator (alteplase) is used to dissolve intraocular fibrinous clots and in the pleural cavity for treatment of fibrinous pleuropneumonia.
Historically, warfarin (a vitamin K antagonist) was used as an anticoagulant in veterinary medicine. Because of marked interindividual variation in its efficacy, however, coupled with a narrow therapeutic index and the broad availability of safer alternatives, the use of warfarin is no longer recommended.
