Anticoagulation in an Older Adult Who Falls
An 82-year-old woman with permanent atrial fibrillation is seen in clinic with her daughter. Her CHA2DS2-VASc score is 5 (age, hypertension, diabetes, prior TIA, female sex) and her HAS-BLED score is 3. She has fallen twice in the past three months, once fracturing her wrist. She lives alone, uses a walker, and scores 27/30 on the MMSE. Medications include amlodipine, metformin, amitriptyline 25 mg at bedtime for neuropathic pain, zolpidem 5 mg for sleep, and vitamin D. Weight is 52 kg and serum creatinine is 1.5 mg/dL. She takes no anticoagulant. Her daughter has read about bleeding risk and asks that her mother not be started on "blood thinners."
1. How do you decide whether to anticoagulate, and if so, which agent and what dose? Show the calculation and the competing-risk reasoning.
Read the worked answer
Creatinine clearance (Cockcroft-Gault): (140 − 82) × 52 ÷ (72 × 1.5) × 0.85 ≈ 24 mL/min.
Two scores point opposite ways, and neither is an order:
- CHA2DS2-VASc 5 → roughly 6–7%/year stroke risk untreated; anticoagulation reduces that by about two-thirds.
- HAS-BLED 3 is a checklist of modifiable factors (sedatives, NSAIDs, alcohol, uncontrolled BP), not a veto.
Falls are the stated reason she is untreated, but the arithmetic is lopsided. For fall-related subdural bleeding to outweigh stroke prevention, a patient would need on the order of hundreds of falls per year. Two falls in three months is nowhere close.
Agent: apixaban over warfarin - less intracranial hemorrhage, no INR monitoring, fewer drug interactions.
Dose: reduce to 2.5 mg BID only if ≥2 of: age ≥80, weight ≤60 kg, creatinine ≥1.5 mg/dL. She meets all three → apixaban 2.5 mg twice daily. CrCl 24 does not prohibit use.
With the daughter: name the trade-off, quantify it in her mother's terms, and pair the prescription with a fall-prevention plan so she is not choosing between stroke and hemorrhage.
2. Five months later she is brought to the emergency department after a mechanical fall in her kitchen, striking her head on a cabinet. She did not lose consciousness, has no vomiting or focal deficit, and GCS is 15. She took apixaban 6 hours ago. What is your management, and when do you restart anticoagulation?
Read the worked answer
A head strike in an anticoagulated patient is a brain-injury question until imaging says otherwise. Absence of LOC, vomiting, or deficit does not exclude intracranial hemorrhage, and delayed bleeds do occur.
- Non-contrast CT head now - do not wait for symptoms.
- Note the last dose (6 hours → near peak effect), examine the scalp for hematoma, and screen for interacting drugs (NSAIDs, SSRIs).
- If CT is negative and she is intact: observe with serial neurologic checks - 4–6 hours of observation is a common minimum, and many protocols observe longer in higher-risk patients. There is no role for prophylactic reversal; andexanet alfa and 4-factor PCC are for proven major bleeding or ICH, not for a negative scan.
- If CT shows hemorrhage: reverse (andexanet alfa preferred; 4F-PCC if unavailable), neurosurgery consult, strict BP control, ICU admission.
- Restarting after a negative scan: usually resume within 24–72 hours, balancing a few days of stroke risk against re-bleeding. Involve the patient and daughter, and document the shared decision explicitly rather than letting the drug lapse by default.
3. Her daughter asks what else can be done so that "this doesn't happen again." Review the medication list and the additional risk-reduction steps you would take.
Read the worked answer
Two of her current drugs are manufacturing the very risk we are trying to manage, and both are Beers-listed in older adults:
- Zolpidem - stop. Minimal benefit for chronic insomnia, clear fall and fracture risk; substitute sleep hygiene/CBT-I.
- Amitriptyline - taper and stop. Anticholinergic, orthostatic, sedating. If neuropathic pain still needs treatment, choose a safer agent (e.g., duloxetine if renal function allows, topical lidocaine, gabapentinoid with caution).
- Check orthostatic vitals; review alcohol, vision, footwear, home hazards; refer to physical therapy for gait and balance training.
Bone health is part of bleeding prevention. A wrist fracture at 82 is an osteoporosis-defining event. DEXA, calcium/vitamin D, and an antiresorptive reduce the chance that the next fall produces a fracture or a serious bleed.
Frame it for the daughter: "We are going to lower her stroke risk and her bleeding risk at the same time - by removing the medicines that make her fall and by treating her bones." That reframes anticoagulation as one part of a plan rather than a gamble.