Abciximab side effects

Side effects
Bleeding

Intracranial Hemorrhage and Stroke

Thrombocytopenia

Allergic Reactions

Other Adverse Reactions

Immunogenicity

Overview
Many of the side effects of abciximab are due to its anti-platelet effects. This includes an increased risk of bleeding. The most common type of bleeding due to abciximab is gastrointestinal hemorrhage. If severe or intractable bleeding develops, the infusion of the drug should be discontinued. Platelets can be administered to partially reverse the effect of the drug. Given that the drug binds avidly to the platelets that it is already bound to, the drug will not bind to new platelets.

Thrombocytopenia is a rare but known serious risk. Abciximab-induced thrombocytopenia can typically be treated with transfusion of platelets. Abciximab induced thrombocytopenia can last for five days after initial drug administration. Transfusing platelets is the only known treatment and may have limited effectiveness as the drug may also bind to the new platelets.

Bleeding
Abciximab has the potential to increase the risk of bleeding, particularly in the presence of anticoagulation, e.g., from heparin, other anticoagulants or thrombolytics. Bleeding in the Phase 3 trials was classified as major, minor or insignificant by the criteria of the Thrombolysis in Myocardial Infarction study group. Major bleeding events were defined as either an intracranial hemorrhage or a decrease in hemoglobin greater than 5 g/dL. Minor bleeding events included spontaneous gross hematuria, spontaneous hematemesis, observed blood loss with a hemoglobin decrease of more than 3 g/dL, or a decrease in hemoglobin of at least 4 g/dL without an identified bleeding site. Insignificant bleeding events were defined as a decrease in hemoglobin of less than 3 g/dL or a decrease in hemoglobin between 3-4 g/dL without observed bleeding. In patients who received transfusions, the number of units of blood lost was estimated through an adaptation of the method of Landefeld, et al.

In the EPIC trial, in which a non-weight-adjusted, longer-duration heparin dose regimen was used, the most common complication during Abciximab therapy was bleeding during the first 36 hours. The incidences of major bleeding, minor bleeding and transfusion of blood products were significantly increased. Major bleeding occurred in 10.6% of patients in the Abciximab bolus plus infusion arm compared with 3.3% of patients in the placebo arm. Minor bleeding was seen in 16.8% of Abciximab bolus plus infusion patients and 9.2% of placebo patients. Approximately 70% of Abciximab-treated patients with major bleeding had bleeding at the arterial access site in the groin. Abciximab-treated patients also had a higher incidence of major bleeding events from gastrointestinal, genitourinary, retroperitoneal, and other sites.

Bleeding rates were reduced in the CAPTURE trial, and further reduced in the EPILOG and EPISTENT trials by use of modified dosing regimens and specific patient management techniques. In EPILOG and EPISTENT, using the heparin and Abciximab dosing, sheath removal and arterial access site guidelines described under PRECAUTIONS, the incidence of major bleeding in patients treated with Abciximab and low-dose, weight-adjusted heparin was not significantly different from that in patients receiving placebo.

Subgroup analyses in the EPIC and CAPTURE trials showed that non-CABG major bleeding was more common in Abciximab patients weighing ≤ 75 kg. In the EPILOG and EPISTENT trials, which used weight-adjusted heparin dosing, the non-CABG major bleeding rates for Abciximab-treated patients did not differ substantially by weight subgroup.

Although data are limited, Abciximab treatment was not associated with excess major bleeding in patients who underwent CABG surgery. (The range among all treatment arms was 3-5% in EPIC, and 1-2% in the CAPTURE, EPILOG, and EPISTENT trials.) Some patients with prolonged bleeding times received platelet transfusions to correct the bleeding time prior to surgery. (see PRECAUTIONS: Restoration of Platelet Function.) Pulmonary alveolar hemorrhage has been rarely reported during use of Abciximab. This can present with any or all of the following in close association with ReoPro administration: hypoxemia, alveolar infiltrates on chest x-ray, hemoptysis, or an unexplained drop in hemoglobin.

Intracranial Hemorrhage and Stroke
The total incidence of intracranial hemorrhage and non-hemorrhagic stroke across all four trials was not significantly different, 9/3023 for placebo patients and 15/4680 for Abciximab-treated patients. The incidence of intracranial hemorrhage was 3/3023 for placebo patients and 7/4680 for Abciximab patients.

Thrombocytopenia
In the clinical trials, patients treated with Abciximab were more likely than patients treated with placebo to experience decreases in platelet counts.

Among patients in the EPILOG and EPISTENT trials who were treated with Abciximab plus low-dose heparin, the proportion of patients with any thrombocytopenia (platelets less than 100,000 cells/µL) ranged from 2.5 to 3.0%. The incidence of severe thrombocytopenia (platelets less than 50,000 cells/µL) ranged from 0.4 to 1.0% and platelet transfusions were required in 0.9 to 1.1%, respectively. Modestly lower rates were observed among patients treated with placebo plus standard-dose heparin. Overall higher rates were observed among patients in the EPIC and CAPTURE trials treated with Abciximab plus longer duration heparin: 2.6 to 5.2% were found to have any thrombocytopenia, 0.9 to 1.7% had severe thrombocytopenia, and 2.1 to 5.5% required platelet transfusion, respectively.

In a readministration registry study of patients receiving a second or subsequent exposure to Abciximab (see PRECAUTIONS: Readministration) the incidence of any degree of throm-bocytopenia was 5%, with an incidence of profound thrombocytopenia of 2% ( < 20,000 cell/µL). Factors associated with an increased risk of thrombocytopenia were a history of thrombocytopenia on previous Abciximab exposure, readministration within 30 days, and a positive HACA assay prior to the readministration.

Among 14 patients who had thrombocytopenia associated with a prior exposure to Abciximab, 7(50%) had recurrent thrombocytopenia. In 130 patients with a readministration interval of 30 days or less, 25 (19%) developed thrombocytopenia. Severe thrombocytopenia occurred in 19 of these patients. Among the 71 patients who had a positive HACA assay at baseline, 11 (15%) developed thrombocytopenia, 7 of which were severe.

Allergic Reactions
There have been rare reports of allergic reactions, some of which were anaphylaxis (see WARNINGS: Allergic Reactions).

Other Adverse Reactions
The following additional adverse events from the EPIC, EPILOG and CAPTURE trials were reported by investigators for patients treated with a bolus plus infusion of Abciximab at incidences which were less than 0.5% higher than for patients in the placebo arm.

Cardiovascular System: ventricular tachycardia (1.4%), pseudoaneurysm (0.8%), palpitation (0.5%), arteriovenous fistula (0.4%), incomplete AV block (0.3%), nodal arrhythmia (0.2%), complete AV block (0.1%), embolism (limb)(0.1%); thrombophlebitis (0.1%);

Gastrointestinal System: dyspepsia (2.1%), diarrhea (1.1%), ileus (0.1%), gastroesophogeal reflux (0.1%); Hemic and Lymphatic System: anemia (1.3%), leukocytosis (0.5%), petechiae (0.2%);

Nervous System: dizziness (2.9%), anxiety (1.7%), abnormal thinking (1.3%), agitation (0.7%), hypesthesia (0.6%), confusion (0.5%) muscle contractions (0.4%), coma (0.2%), hypertonia (0.2%), diplopia (0.1%);

Respiratory System: pneumonia (0.4%), rales (0.4%), pleural effusion (0.3%), bronchitis (0.3%), bronchospasm (0.3%), pleurisy (0.2%), pulmonary embolism (0.2%), rhonchi (0.1%);

Musculoskeletal System: myalgia (0.2%);

Urogenital System: urinary retention (0.7%), dysuria (0.4%), abnormal renal function (0.4%), frequent micturition (0.1%), cystalgia (0.1%), urinary incontinence (0.1%), prostatitis (0.1%);

Miscellaneous: pain (5.4%), sweating increased (1.0%), asthenia (0.7%), incisional pain (0.6%), pruritus (0.5%), abnormal vision (0.3%), edema (0.3%), wound (0.2%), abscess (0.2%), cellulitis (0.2%), peripheral coldness (0.2%), injection site pain (0.1%), dry mouth (0.1%), pallor (0.1%), diabetes mellitus (0.1%), hyperkalemia (0.1%), enlarged abdomen (0.1%), bullous eruption (0.1%), inflammation (0.1%), drug toxicity (0.1%).

Immunogenicity
As with all therapeutic proteins, there is a potential for immunogenicity. In the EPIC, EPILOG, and CAPTURE trials, positive HACA responses occurred in approximately 5.8% of these patients receiving a first exposure to Abciximab. No increase in hypersensitivity or allergic reactions was observed with Abciximab treatment (see WARNINGS: Allergic Reactions).

In a study of readministration of Abciximab to patients (see PRECAUTIONS: Readministration) the overall rate of HACA positivity prior to the readministration was 6% and increased post-readministration to 27%. Among the 36 subjects receiving a fourth or greater Abciximab exposure, HACA positive assays were observed post-readministration in 16 subjects (44%). There were no reports of serious allergic reactions or anaphylaxis (see WARNINGS: Allergic Reactions). HACA positive status was associated with an increased risk of throm-bocytopenia (see PRECAUTIONS: Thrombocytopenia).

The data reflect the percentage of patients whose test results were considered positive for antibodies to Abciximab using an ELISA assay, and are highly dependent on the sensitivity and specificity of the assay. Additionally, the observed incidence of antibody positivity in an assay may be influenced by several factors including sample handling, timing of sample collection, concomitant medications, and underlying disease. For these reasons, comparison of the incidence of antibodies to Abciximab with the incidence of antibodies to other products may be misleading.