- Meds can trigger antibody mediated platelet destruction
- Heparin→ Heparin Induced Thrombocytopenia (HIT): Typically 50% decline w/in 5-10d of treatment, or < 1 d if prior exposure to heparin
- Other Meds: H2-blockers, penicillins, NSAIDs, Quinine, Bactrim, Vancomycin, other antibiotics and meds of other classes
- For HIT, prior exposure to heparin
- Bleeding and drop in platelets timed w/use of a medication
- HIT: thrombocytopenia associated with arterial and/or venous thrombosis (e.g. skin necrosis, DVT, unexplained arterial thrombosis), adrenal hemorrhage, anaphylactic-type reaction after IV heparin infusion; 4Ts score can help w/diagnosis
- Mucosal bleeding
- DVT or otherwise unexplained arterial events, temporally related to heparin exposure