Imitrex - sumatriptan - and ITP

Does anyone know of a connection between Imitrex (sumatriptan) and thrombocytopenia?

My wife is a long-time regular user of Imitrex for treatment of her migraines, and recently was diagnosed with ITP. Repeatedly, people have told her that Imitrex is known to cause thrombocytopenia, but I cannot find that anywhere on the web. Years ago, pre-ITP, she complained of bruising to her former neurologist, and he told her it was common with Imitrex.

I have searched the literature and cannot find a significant connection. There were no such reports out of 6200 pre-marketing patients. There have been post-marketing reports of thrombocytopenia among Imitrex users, but no strong connection.

Any thoughts?

Any drug has the potential to cause ITP, but chances are if she used it for a long time, it wasn't the cause. People can bruise without a low platelet count. My counts are normal and I bruise all the time from my medium sized dogs jumping on me or any other insignificant bump. Your wife can ask her doctors if any CBC's over the years turned up low platelets, then she'd know how long it's been going on.

Even if it was the cause, sometimes stopping the drug does not make ITP go away.