ozagrel and Hemorrhage

Ozagrel sodium (ozagrel), a thromboxane A2 synthesis inhibitor, is used for ischemic stroke patients in several countries, despite a lack of strict evidence of its benefits. We investigated whether ozagrel was beneficial for patients with atherothrombotic stroke or lacunar infarction.. This was a retrospective observational study using the Diagnosis Procedure Combination database in Japan. We identified patients with atherothrombotic stroke or lacunar infarction who were admitted to 781 hospitals from July 1, 2010 to March 31, 2012. Propensity score-matched analyses were performed separately for patients with atherothrombotic stroke and those with lacunar infarction, which balanced differences in baseline characteristics between patients who received ozagrel (ozagrel group) and those who did not (control group) in each stroke subtype. The modified Rankin Scale scores at discharge and occurrence of hemorrhagic complications after admission were compared between the ozagrel and control groups.. After the propensity score matching, 2726 pairs of patients with atherothrombotic stroke and 1612 pairs of patients with lacunar infarction were analyzed. Ordinal logistic regression analyses showed that ozagrel use was not significantly associated with modified Rankin Scale score at discharge in patients with atherothrombotic stroke (odds ratio: .99; 95% confidence interval: .88-1.11) or in those with lacunar infarction (odds ratio: 1.00; 95% confidence interval: .87-1.16). The occurrence of hemorrhagic complications did not differ significantly between the ozagrel and control groups.. The present study suggested that ozagrel was safe to use but did not improve functional outcomes in patients with atherothrombotic or lacunar infarction.

Topics: Adult; Aged; Aged, 80 and over; Brain Ischemia; Chi-Square Distribution; Disability Evaluation; Enzyme Inhibitors; Female; Hemorrhage; Humans; Logistic Models; Male; Matched-Pair Analysis; Methacrylates; Middle Aged; Patient Discharge; Propensity Score; Recovery of Function; Retrospective Studies; Risk Factors; Stroke; Stroke, Lacunar; Thromboxane-A Synthase; Treatment Outcome

The advantage of platelet integrin GPIIb-IIIa receptor antagonists in the prevention of thrombotic occlusion was clearly proven in patients who underwent interventional treatment of the coronary artery, but its value in cerebral ischemia is still under investigation. The expectation of intracranial hemorrhage on strong inhibition of platelet function restricts its application in cerebral ischemia. To minimize bleeding while keeping antithrombotic activity, we have tried to find an appropriate approach using a combination of platelet integrin GPIIb-IIIa receptor antagonist and some other antithrombotic agents. The time to thrombotic occlusion was measured using a photothrombotic occlusion model of guinea pig middle cerebral artery. A platelet integrin GPIIb-IIIa receptor antagonist, ME3277 (sodium hydrogen [4-[(4,5,6,7-tetrahydrothieno [3,2-c] pyridin-2-yl) carbonylamino] acetyl-o-phenylene] dioxydiacetate), delayed occlusion time from 7.3 min in vehicle to 15.0, 20.6 and 25.9 min (P<0.05) at 0.1, 0.3 and 1 mg/kg, respectively. ME3277 profoundly inhibited ex vivo platelet aggregation and the highest dose of ME3277 prolonged (3.5 folds, P<0.01) the bleeding time measured in the hind paw. A thromboxane A(2) synthase inhibitor, sodium ozagrel, significantly delayed occlusion time to 19.5 min at 30 mg/kg (P<0.05) while it did not affect bleeding time or platelet aggregation. ME3277 (0.1 mg/kg) in combination with 10 mg/kg sodium ozagrel synergistically delayed occlusion time (sodium ozagrel alone; 7.9 min, combination; 26.1 min, P<0.05 vs. ME3277 alone). Sodium ozagrel did not affect ex vivo platelet aggregation or bleeding time when combined with 0.1 mg/kg of ME3277. This synergy was cancelled by combination with 30 mg/kg aspirin (14.7 min). A thromboxane A(2) receptor antagonist, vapiprost (0.1 mg/kg), did not enhance the antithrombotic efficacy of ME3277. These results imply that local prostacyclin production enhances the in vivo antithrombotic effect of the platelet integrin GPIIb-IIIa receptor antagonist. Therefore, the thromboxane A(2) synthase inhibitor allowed a reduction in the dose level of the platelet integrin GPIIb-IIIa receptor antagonist for cerebral thrombosis, which resulted in a reduced risk of bleeding.

Topics: Amides; Animals; Anticoagulants; Aspirin; Biphenyl Compounds; Bleeding Time; Blood Platelets; Drug Synergism; Fibrinolytic Agents; Guinea Pigs; Hemorrhage; Heparin; Heptanoic Acids; Hindlimb; Male; Methacrylates; Middle Cerebral Artery; Partial Thromboplastin Time; Platelet Aggregation; Platelet Aggregation Inhibitors; Platelet Glycoprotein GPIIb-IIIa Complex; Thromboxane-A Synthase

The prevention of cerebral vasospasm with OKY-046, an imidazole derivative and a thromboxane synthetase inhibitor, was studied co-operatively at ten neurosurgical services. Intravenous administrations of 2, 5 or 10 mu/kg/minute of OKY-046 were given continuously from the earliest possible day to the 14th SAH-day to 82 patients with ruptured cerebral aneurysm. Sixty-eight patients (83%) showed moderate to high high-density (SAH) in their initial CTs. Angiographic vasospasms were seen in 58 patients, representing 71% of all cases or 81% of the 72 cases for which angiograms were available: the vasospasms of 45 patients (55 or 63%) were moderate to severe. Symptomatic vasospasm occurred, however, only in 27 patients (33%): in 18 of those cases, moreover, the symptoms were mild or transient. The conditions of the patients at one month after the SAH were classified into 9 grades from 0 (normal) to 8 (deceased). Fifty-two patients (63%) were classified as 0 or 1, and 64 (78%) as better than 3 (possible daily life unaided). The administration of OKY-046 was proven to decrease TXB2 in the blood. This paper emphasizes the effectiveness of the drug for symptomatic vasospasm, and supports our previous contention that cerebral microthrombosis may play an important role in the pathogenesis of cerebral vasospasm.

Topics: Acrylates; Adult; Aged; Drug Eruptions; Female; Hemorrhage; Humans; Intracranial Aneurysm; Ischemic Attack, Transient; Male; Meclofenamic Acid; Methacrylates; Middle Aged; Recurrence; Subarachnoid Hemorrhage; Thromboxane-A Synthase