Simvastatin-induced thrombocytopaenia: a further case and a brief on its clinical relevance

Statin-Induced Thrombocytopenia in a Young Female: A Case Report and Literature Review

The causal relationship of thrombocytopenia with statin intake has been described in many research articles. Our case discusses the refractory nature of thrombocytopenia in a 22-year-old female, one month following a daily intake of 20 mg atorvastatin. This is the first case ever of drug-induced refractory thrombocytopenia reported in a young patient. We will also discuss previously reported cases of drug-induced thrombocytopenia (DIT) in our manuscript.

Atorvastatin-Induced Refractory Thrombocytopenia

Drug-induced thrombocytopenia is rarely associated with statin medications. We describe the case of a 69-year-old woman who developed refractory thrombocytopenia following atorvastatin use. To our knowledge, this is the fourth reported case of atorvastatin-induced thrombocytopenia and the first reported case of atorvastatin-induced refractory thrombocytopenia. Additionally, we summarize the cases of statin-induced thrombocytopenia reported in the medical literature.

Lovastatin induces platelet apoptosis

Statins are widely used in the prevention of atherosclerosis and treatment of coronary artery disease because of pleiotropic effects on thrombosis. Thrombocytopenia and hemorrhage occurred in some statin-treated patients, but the reason remains unclear. In the current study, we show that lovastatin dose-dependently induces depolarization of mitochondrial inner transmembrane potential, leading to up-regulation of Bak, down-regulation of Bcl-XL, and activation of caspase-3/8/9. Lovastatin treatment did not increase the surface expression of P-selectin or PAC-1 binding but led to strongly reduced collagen- and thrombin-induced platelet aggregation. The integrin αIIbβ3 antagonist, RGDS, inhibited lovastatin-induced apoptosis in both human platelets and Chinese hamster ovary (CHO) cells stably expressing integrin αIIbβ3. The number of circulating platelets in mice was significantly reduced after intraperitoneal injections with lovastatin. Taken together, these data indicate that lovastatin induced caspase-dependent platelet apoptosis. Lovastatin does not incur platelet activation, whereas impairs platelet function and reduces circulating platelets in vivo, suggesting the possible pathogenesis of thrombocytopenia and hemorrhage in patients treated with statins.

Spontaneously recovered severe thrombocytopaenia following zoledronic acid infusion for osteoporosis

Zoledronic acid is widely used for the treatment of various skeletal disorders. While acute phase reactions are commonly seen, hypocalcaemia, femoral shaft fractures, osteonecrosis of the jaw and renal failure are rare. Two cases of fatal thrombocytopaenic purpura have been reported following zoledronic acid infusion. We report a case of non-fatal thrombocytopaenia with spontaneous recovery. A 70-year woman with osteoporosis participated in a research study. Complete blood and platelet counts prior to zoledronic acid infusion were normal (138,000/µL), but had declined slightly from 185,000/µL 2 years ago. One year after the first zoledronic acid infusion, her platelet count declined to 50,000/µL without any clinical manifestations, and rose slowly returning to normal (156,000/µL) over the next 1 year. Extensive evaluation did not reveal any specific abnormalities, and the pathogenesis of her transient severe thrombocytopaenia after two infusions of zoledronic acid remains unclear.

Simvastatin and amlodipine induced thrombocytopenia in the same patient: double trouble and a literature review

WHAT IS KNOWN AND OBJECTIVE

Drug-induced thrombocytopenia (DITP) may be a fatal adverse reaction to many drugs. It is often misdiagnosed as primary immune thrombocytopenia (ITP), and thus diagnosis can be delayed and patients can be treated inappropriately. Amlodipine a calcium-channel blocker, and simvastatin, a statin, have very rarely been implicated in DITP. We report on an investigation of the causal relationship of amlodipine and simvastatin with thrombocytopenia occurring in the same patient, and review the literature.

CASE SUMMARY

We present the case of a 78-year-old female hypertensive diabetic patient with three successive DITPs. The first attack of acute severe thrombocytopenia occurred after a 2-week course of amlodipine, and was initially misdiagnosed as ITP. Her platelet count normalized after the amlodipine was discontinued. The second attack followed her restarting simvastatin 3 weeks later. She had stopped it 2 months earlier having previously taken it for over 5 years. Again, she recovered once the simvastatin was discontinued. The third DITP attack occurred when she accidently took a single dose of amlodipine 9 months later.

WHAT IS NEW AND CONCLUSION

We provide clear evidence of a causal association of amlodipine with thrombocytopenia, and probable evidence of a causal association of simvastatin with thrombocytopenia. This is the first reported case of DITPs occurring with two of the most widely prescribed drugs in the same patient. Many hypertensive patients need to take multiple drugs in order to achieve their treatment goals and this increases their risk of drug-induced adverse reactions and makes identification of the causal drug (or drugs) extremely difficult.

Non-lipid effects of rosuvastatin-fenofibrate combination therapy in high-risk Asian patients with mixed hyperlipidemia

OBJECTIVE

The aim of this study is to compare the non-lipid effects of rosuvastatin-fenofibrate combination therapy with rosuvastatin monotherapy in high-risk Asian patients with mixed hyperlipidemia.

METHODS

A total of 236 patients were initially screened. After six weeks of diet and life style changes, 180 of these patients were randomly assigned to receive one of two regimens: rosuvastatin 10 mg plus fenofibrate 160 mg or rosuvastatin 10 mg. The primary outcome variables were the incidences of muscle or liver enzyme elevation. The patients were followed for 24 weeks during drug treatment and for an additional four weeks after drug discontinuation.

RESULTS

The rates of the primary outcome variables were similar between the two groups (2.8% and 3.9% in the combination and the rosuvastatin groups, respectively, p=1.00). The combination group had more, but not significantly, common treatment-related adverse events (AEs) (13.3% and 5.6%, respectively) and drug discontinuation due to AEs (10.0% and 3.3%, respectively) than the rosouvastatin group. Combination therapy was associated with higher elevations in homocysteine, blood urea nitrogen, and serum creatinine, whereas elevation in alanine aminotransferase was greater in the rosuvastatin group. Leukocyte count and hemoglobin level decreased to a greater extent in the combination group. The combination group showed greater reductions in TG and elevation in HDL-cholesterol.

CONCLUSION

In our study population, the rosuvastatin-fenofibrate combination resulted in comparable incidences of myo- or hepatotoxicity as rosuvastatin monotherapy. However, this combination may need to be used with caution in individuals with underlying pathologies such as renal dysfunction (NCT01414803).

Atorvastatin-related thrombocytopenic purpura

A 44-year-old male patient with a single vessel ischaemic heart disease was referred to the lipid clinic for management of hypercholesterolaemia after an episode of admission with thrombocytopenic purpura secondary to atorvastatin. Atorvastatin was discontinued and his platelet counts improved gradually with steroids. He is now established on a different statin with no further episodes of thrombocytopenia. Though a drug challenge was never done, an idiosyncratic reaction to the initial statin seems to be the most likely cause.