Intervention: Clopidogrel
Trial phase: Phase 3
ATC code: B01AC04
SMILES: [H][C@@](C(=O)OC)(c1ccccc1Cl)N1CCc2sccc2C1
Sex: All
Age groups: Adult | Older Adult
Healthy volunteers: No
Participants at risk: 2432
Group description: Patients assigned to clopidogrel in addition to aspirin

Clopidogrel: Loading dose of 600mg followed by 75 milligrams, oral, one tablet daily for 89 days
Eligibility criteria:
Inclusion Criteria:

Neurological deficit (based on history or exam) attributed to focal brain ischemia and EITHER:

High risk TIA: Complete resolution of the deficit at the time of randomization AND ABCD2 score of (greater than or equal to) 4 OR
Minor ischemic stroke: residual deficit with NIHSS of (less than or equal to) 3 at the time of randomization
Ability to randomize within 12 hours of time last known free of new ischemic symptoms.
Head CT or MRI ruling out hemorrhage or other pathology, such as vascular malformation, tumor, or abscess, that could explain symptoms or contraindicate therapy.
Ability to tolerate aspirin at a does of 50-325 mg/day.

Exclusion Criteria

Age <18 years
TIA symptoms limited to isolated numbness, isolated visual changes, or isolated dizziness/vertigo.
In the judgment of the treating physician, a candidate for thrombolysis, endarterectomy or endovascular intervention, unless the subject declines both endarterectomy and endovascular intervention at the time of evaluation for eligibility.
Receipt of any intravenous or intra-arterial thrombolysis within 1 week prior to index event.
Gastrointestinal bleed or major surgery within 3 months prior to index event.
History of nontraumatic intracranial hemorrhage.
Clear indication for anticoagulation (e.g., warfarin, heparin) anticipated during the study period (atrial fibrillation, mechanical heart valve, deep venous thrombosis, pulmonary embolism, antiphospholipid antibody syndrome, hypercoagulable state).
Qualifying ischemic event induced by angiography or surgery.
Severe non-cardiovascular comorbidity with life expectancy <3 months.

Contraindication to clopidogrel or aspirin.

Known allergy
Severe renal (serum creatinine >2 mg/dL or 176.8umol/L) or hepatic insufficiency (prior or concurrent diagnosis, with International Normalized Ratio (INR)>1.5 or any resultant complication, such as variceal bleeding, encephalopathy, or icterus)
Hemostatic disorder or systemic bleeding in the past 3 months
Current thrombocytopenia (platelet count <100 x10^9/l) or neutropenia (<1 x10^9/l)
History of drug-induced hematologic or hepatic abnormalities
Anticipated requirement for long-term (>7 day) non-study antiplatelet drugs (eg, dipyridamole, clopidogrel, ticlopidine), or Non-steroidal Anti-inflammatory Drugs (NSAIDs) affecting platelet function (such as prior vascular stent or arthritis).
Inability to swallow medications.
At risk for pregnancy: premenopausal or post menopausal woman within 12 months of last menses without a negative pregnancy test or not committing to adequate birth control (e.g., oral contraceptive, two methods of barrier birth control, or abstinence).
Unavailability for follow-up.
Signed and dated informed consent not obtained from patient.
Other neurological conditions that would complicate assessment of outcomes during follow-up.
Ongoing treatment in another study of an investigational therapy that may potentially interact with study drug, or treatment in such a study within the last 7 days.
Previously enrolled in the POINT study.