Combination of Ticlopidine and Clopidogrel

• both agents are from the same group- thienopyridine, with a similar structure and mechanism
• the use of combination is not supported by any guidelines
• moreover, Ticlopidine is a strong CYP2C19 inhibitor. This leads to decreased serum concentrations of active metabolites of Clopidogrel. (interaction: major/fairly reliable)

Recommendation:

• The combination of aspirin and clopidogrel might be considered for initiation within 24 hours of a minor ischemic stroke or TIA and for continuation for 90 days (Class IIb; Level of Evidence B)
• For patients with a history of ischemic stroke or TIA, AF, and CAD, the usefulness of adding antiplatelet therapy to Vitamin K Antagonist therapy is uncertain for purposes of reducing the risk of ischemic cardiovascular and cerebrovascular events (Class IIb; Level of Evidence C). 
• Unstable angina and coronary artery stenting represent special circumstances in which management may warrant DAPT/VKA therapy.

References:

1. Lexicomp
2. AHA/ASA Guideline: Guidelines for the Prevention of Stroke in Patients With Stroke and Transient Ischemic Attack