From the FDA Drug Label
• History of blood clots in the legs, lungs, eyes, brain, or elsewhere, or a past history of these conditions • Abnormal Blood Clotting: Use of progestational drugs, such as norethindrone acetate tablets, has been associated with changes in the blood-clotting system These changes allow the blood to clot more easily, possibly allowing clots to form in the bloodstream.
Norethindrone should not be given to patients with a history of blood clots. Although thrombocytosis (high platelet count) is not directly mentioned as a contraindication, the increased risk of blood clotting associated with norethindrone suggests that it may not be suitable for patients with thrombocytosis. Therefore, it is recommended to avoid giving norethindrone to patients with high platelet counts due to the potential increased risk of blood clots 1.
From the Research
Norethindrone should generally be avoided in patients with thrombocytosis due to increased risk of thrombotic events. Progestins like norethindrone can potentially increase the risk of blood clots, and patients with thrombocytosis already have an elevated risk of thrombosis due to their high platelet count. If hormonal therapy is necessary, non-hormonal alternatives should be considered first. In cases where norethindrone is deemed clinically necessary, it should only be used after careful risk-benefit assessment and with close monitoring of platelet counts and signs of thrombosis, as suggested by studies such as 2. The concern stems from progestins' ability to increase coagulation factors and potentially decrease anticoagulant proteins, which, combined with the already elevated platelet count in thrombocytosis, creates a potentially dangerous hypercoagulable state. Some studies, like 3, have investigated the effects of progestin-only hormonal contraceptives on platelet aggregation, but the most recent and relevant evidence, such as 4 and 2, supports caution in using norethindrone in patients with thrombocytosis. Patients should be educated about warning signs of thrombosis including leg pain/swelling, chest pain, shortness of breath, severe headache, or vision changes, and instructed to seek immediate medical attention if these occur. Key considerations in managing patients with thrombocytosis include assessing the risk of thrombotic events and balancing this against the potential benefits of hormonal therapy, as discussed in 5 and 6. Ultimately, the decision to use norethindrone in a patient with thrombocytosis should be made on a case-by-case basis, taking into account the individual's specific risk factors and medical history, and prioritizing their morbidity, mortality, and quality of life outcomes.