Ticlopidine, sold under the brand name Ticlid, is a medication used to reduce the risk of thrombotic strokes.
Medical uses
Ticlopidine is indicated for the prevention of strokes and when combined with aspirin, for people with a new coronary stent to prevent closure.
Heart disease
When a patient needs to have a stent placed in one of the vessels around their heart, it is important that that stent stay open to keep blood flowing to the heart. Therefore, patients with stents must take medications after the procedure to help maintain that blood flow. Ticlopidine, taken together with aspirin, is FDA approved for this purpose, and in studies it has been shown to work better than aspirin alone or aspirin with an anticoagulant. However, ticlopidine’s serious side effects make it less useful than its cousin, clopidogrel. Current recommendations no longer recommend ticlopidine’s use.
Contraindications
The use of ticlopidine is contraindicated in anyone with:
- Increased risk of bleeding (i.e. frequent falls, gastrointestinal bleeds)
- History of hematological disease
- Severe liver disease
- History of allergic reaction to ticlopidine or any thienopyridine drug such as clopidogrel
Because of the increased risk of bleeding, patients taking ticlopidine should discontinue the medication 10–14 days before surgery. and CYP2B6 and thus can affect blood levels of medications metabolized by these systems.
Mechanism of action
Ticlopidine is a tetrahydro-thienopyridine which, when metabolized by the body, irreversibly blocks the P2Y12 component of the ADP receptor on the surface of platelets. Without ADP, fibrinogen does not bind to the platelet surface, preventing platelets from sticking to each other. Anti-platelet effects start within 2 days and reach their maximum by 6 days of therapy. Ticlopidine’s effects persist for 3 days after discontinuing ticlopidine although it may take 1–2 weeks for platelet function to return to normal, as the medication affects platelets irreversibly. Therefore, new platelets must be formed before platelet function normalizes. Starting in 1978 the drug was marketed in France under the brand name Ticlid for people at high risk for thrombotic events, who had just come out of heart surgery, were undergoing hemodialysis, had peripheral vascular disease, or who were otherwise at risk for strokes and ischemic heart disease.
Ticlopidine was brought to market in the US by Syntex, which got the drug approved in 1991. Syntex was acquired by the Roche group in 1994. The first generic ticlopidine hydrochloride was FDA approved in 1999. As of April 2015, Roche, Caraco, Sandoz, Par, Major, Apotex, and Teva had discontinued generic ticlopidine and no ticlopidine preparations were available in the US.
Research
Soon after its release, studies regarding ticlopidine found it had the potential to be helpful for other diseases including peripheral vascular disease, diabetic retinopathy, and sickle cell disease. However, none had enough evidence for FDA approval. Due to the blood cell side effects associated with ticlopidine, researchers for treatments for these conditions have turned to other avenues.