RESUMO
The aim of current study was evaluating the frequency of clopidogrel resistance and its impact on clinical outcome of patients in Iranian patients. Patients undergoing percutaneous coronary intervention in Imam Hussein Medical center, Tehran, Iran, who received standard dosage of clopidogrel (Plavix®, Sanofi, France, 600 mg loading dose and 75 mg/day afterward) were recruited. Platelet aggregation was measured using light transmission aggregometer. The patients were categorized as responder (platelet aggregation less than 43%) and non-responder (platelet aggregation more than 43%). All patients were evaluated for major adverse cardio vascular events one month and 3 years after the angioplasty based on MACE criteria by phone contact. One hundred and five patients with average age of 60.30 ± 12.2 years entered the study of whom 26 (24.76%) did not respond to clopidogrel. None of patients experienced cardiac events one month after PCI. Three years after PCI, data were collected from 55 (69.62%) and 10 (38.46%) subjects in responder and non-responder groups, respectively. MACE criteria was positive in 4 patients, 3 (5.45%) in responder and 1 (10%) in non-responder group (p = 0.28). We did not find any significant differences between clopidogrel resistance and past medical history. In drug history 1 (1.26%) and 4 (15.38%) patients received omeprazole with clopidogrel in responder and none-responder group, respectively (p = 0.003). This study showed 24.76% resistance to clopidogrel in Iranian population but, we did not find any correlation between clopidogrel resistance and cardiac events in follow up maybe due to study limitations particularly missed follow-up in non-responder patients.
RESUMO
Drug-drug interactions (DDIs) can lead to increased toxicity or reduction in therapeutic efficacy. This study was designed to assess the incidence of potential drug interactions (PDI) and rank their clinical value in post coronary care unit (Post-CCU) of a teaching hospital in Tehran, Iran. In this prospective study, three pharmacists with supervision of a clinical pharmacist actively gathered necessary information for detection of DDIs. Data were tabulated according to the combinations of drugs in treatment chart. Verification of potential drug interactions was carried out using the online Lexi-Interact™ 2011. A total of 203 patients (113 males and 90 females) were enrolled in the study. The mean age of patients was 61 ± 12.55 years (range = 26-93). A total of 90 drugs were prescribed to 203 patients and most prescribed drugs were atorvastatin, clopidogrel and metoprolol. Mean of drugs was 11.22 per patient. A total of 3166 potential drug interactions have been identified by Lexi- Interact™, 149 (4.71%) and 55 (1.73%) of which were categorized as D and X, respectively. The most serious interactions were clopidogrel+omeprazole and metoprolol+salbutamol. Drug interactions leading to serious adverse effects are to be cautiously watched for when multiple drugs are used simultaneously. In settings with multiple drug use attendance of a pharmacist or clinical pharmacist, taking the responsibility for monitoring drug interactions and notifying the physician about potential problems could decrease the harm in patient and increase the patient safety.
RESUMO
To study the resistance to standard dosage of clopidogrel among Iranian patients following percutaneous coronary intervention measured by platelet aggregation test. Patients undergoing percutaneous coronary intervention in Imam Hussein Medical center, Tehran, Iran, who were under treatment with aspirin, but had no history of clopidogrel usage, entered the study. Patients received standard dosage of clopidogrel (Plavix(®), Sanofi, France, 600 mg loading dose and 75 mg/day afterward). Platelet aggregation was measured using light transmission aggregometer. The response to the drug was categorized as complete resistance (platelet aggregation decreased less than 10%), intermediate resistance (platelet aggregation decreased between 10 to 30%) and complete response (platelet aggregation decreased to 30% or more). All patients were evaluated for major adverse cardio vascular events one month after the angioplasty based on MACE criteria by phone contact. Thirty-one patients with a mean age of 59 ± 13 entered the study. Sixty-five percent of patients showed complete response to clopidogrel (95% CI: 45% to 81%), 22% showed intermediate resistance (95% CI: 10-41%) and 13% showed complete resistance (95% CI: 4-30%). One month after the angioplasty, no major adverse cardiovascular event was recorded. Based on our findings, it seems that there is no major difference between Iranian population and other studies regarding the resistance to clopidogrel. Due to the limited number of participants in our study, further investigations with higher number of patients are recommended to more precisely calculate the percentage of resistance among Iranian patients.
