Can lisinopril (angiotensin-converting enzyme inhibitor) cause thrombocytopenia (low platelet count)?

From the Guidelines

Lisinopril is not known to directly lower platelet counts as a common side effect. Lisinopril is an angiotensin-converting enzyme (ACE) inhibitor primarily used to treat high blood pressure, heart failure, and to protect the kidneys in people with diabetes or heart disease. While some blood pressure medications can affect blood cell counts, the evidence from the ALLHAT trial, which compared the effectiveness of an ACE inhibitor (lisinopril) versus a calcium-channel blocker (amlodipine) versus a thiazide diuretic (chlorthalidone) as first-line therapy for mild to moderate hypertension, does not mention thrombocytopenia (low platelet count) as a significant side effect of lisinopril 1. In fact, the study focused on the outcomes of combined fatal coronary heart disease or nonfatal myocardial infarction, all-cause mortality, stroke, and combined cardiovascular disease, without reporting any notable effects on platelet counts. Some key points to consider:

• The ALLHAT trial showed no differences between treatments in primary outcome or all-cause mortality, suggesting that lisinopril does not have a significant impact on overall mortality or cardiovascular events compared to other antihypertensive medications 1.
• The study did report some differences in secondary outcomes, such as a higher risk for heart failure in the amlodipine group and higher cholesterol levels and prevalence of hypokalemia in the chlorthalidone group, but these did not translate into increased cardiovascular events or higher mortality rates 1.
• While isolated reports of thrombocytopenia have been associated with ACE inhibitors, including lisinopril, this is considered an uncommon adverse reaction and not a common side effect of the medication. If you're experiencing a decrease in platelet count while taking lisinopril, it's essential to consult with your healthcare provider as this could be due to another underlying condition or medication. Your doctor may need to perform blood tests to determine the cause and might consider alternative medications if lisinopril is suspected to be responsible. Never stop taking prescribed medications without medical guidance.

From the FDA Drug Label

Hematologic: Rare cases of bone marrow depression, hemolytic anemia, leukopenia/neutropenia and thrombocytopenia. Lisinopril may lower platelets, as rare cases of thrombocytopenia have been reported in patients treated with lisinopril 2.

From the Research

Effects of Lisinopril on Platelets

• The study 3 investigated the effects of lisinopril on platelet function and blood rheology in essential hypertension.
• The results showed that lisinopril had no significant effect on platelet counts and platelet aggregation in response to ADP and to arachidonic acid.
• However, lisinopril tended to decrease whole blood viscosity at all shear rates, although this change did not reach statistical significance.
• Lisinopril also increased the erythrocyte aggregation time and decreased the disaggregation shear rate and the disaggregation shear stress, suggesting favorable effects on blood rheology.

Comparison with Other Studies

• The other studies 4, 5, 6, 7 did not investigate the specific effect of lisinopril on platelets.
• These studies focused on the antihypertensive and cardioprotective effects of lisinopril, as well as its efficacy in congestive heart failure and diabetic nephropathy.
• None of these studies reported any significant effects of lisinopril on platelet count or function.

Clinical Relevance

• The findings of the study 3 suggest that lisinopril may have a beneficial effect on blood rheology, but the clinical relevance of this effect requires further investigation.
• The lack of significant effects on platelet count and function in this study and the absence of reports on platelet effects in other studies 4, 5, 6, 7 suggest that lisinopril is unlikely to have a significant impact on platelets.