A Bedbound Elderly Patient on Multiple Medicines
An 82-year-old woman who had a stroke six months ago is bedbound at home and is brought to the dispensary for review. Her current medicines are Tab Warfarin 5 mg once daily for atrial fibrillation, Tab Aspirin 75 mg once daily started by a local doctor for 'blood thinning', Tab Metformin 500 mg twice daily, and Tab Diclofenac 50 mg twice daily which her son buys over the counter for knee pain. Her last INR was done four months ago and was 2.4. The caregiver says she doubles the warfarin dose whenever she forgets a day 'so that it catches up'. She has a nasogastric tube, a red unbroken area over the sacrum, and all her medicines are crushed together into 100 mL of feed. Her most recent creatinine gives an eGFR of 38 mL/min/1.73 m².
1. Identify four medication-related problems in this list and state the specific action and reasoning for each.
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- Warfarin plus aspirin plus diclofenac - triple bleeding risk. Aspirin adds antiplatelet effect with no documented indication (no stent, no recent acute coronary syndrome) in atrial fibrillation, and diclofenac both injures the gastric mucosa and inhibits platelet function. Action: stop aspirin and stop diclofenac; use paracetamol and non-drug measures for knee pain. This is the single change that most reduces her risk of a fatal gastrointestinal or intracranial bleed.
- No INR monitoring for four months. Warfarin's dose is set by the INR, and the target for atrial fibrillation is 2.0–3.0. Action: check INR today and set a monitoring schedule, at least every 4 weeks until stable, then up to 12 weeks.
- Doubling the warfarin dose after a missed day. This produces a supratherapeutic INR and bleeding. Action: correct the rule - if the missed dose is remembered the same day, take it; if not, skip it and resume the normal dose. Never two doses at once.
- Metformin with eGFR 38 mL/min. Metformin should not be started below 45, and if continued in the 30–45 range the dose is capped at 1,000 mg daily with renal function checked every 3 months and the drug held during vomiting, dehydration or contrast imaging. She is already at that ceiling, so action: review the need and dose, and recheck renal function; also consider vitamin B12 deficiency on long-term metformin.
A fifth issue is the red sacral area - a stage 1 pressure injury that needs two-hourly repositioning, offloading and skin care.
2. Explain how the nasogastric tube changes the way these medicines should be given, and what you would check before each dose.
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Route and formulation: only immediate-release tablets may be crushed. Enteric-coated aspirin must not be crushed (use a dispersible 75 mg preparation or stop it, as advised here); sustained-release metformin must not be crushed - switch to the immediate-release form or a liquid. Warfarin tablets can be crushed and given in water.
Technique: give one medicine at a time, never all four mixed into the feed - mixing causes chemical incompatibility, blocked tubes and unpredictable absorption. Flush with about 30 mL of water before the first dose, between each medicine, and 30 mL after the last. Keep the enteral feed volume and timing constant, because feed contains vitamin K and a changing intake alters the INR - coordinate warfarin timing with the feed regimen rather than stopping feeds.
Before each dose check: the ten rights (right patient by identity band, drug, dose, route, time, documentation, reason, to refuse, assessment, education); expiry date and appearance of the medicine; that the tube tip is still in the stomach (mark at the nostril, check the aspirate pH, about 30–50 mL of residual volume returned); and that she is sitting at 30–45° during and for 30 minutes after, to prevent aspiration.
3. Write the counselling you would give the caregiver about warfarin, including what to do about a missed dose and which signs mean she must come back at once.
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How it works: warfarin is a blood thinner whose dose is decided by the INR blood test, not by how she looks or feels. The dose must never be changed, doubled or stopped without the doctor, and she should carry a warfarin record card to every visit.
Missed dose: if you remember on the same day, give the missed dose as soon as you remember. If you only remember the next day, skip the missed dose and give the usual dose at the usual time. Never give two doses together to catch up - that is how serious bleeding happens. Mark each dose on a calendar so nothing is guessed.
Food and other medicines: green leafy vegetables are good and should not be avoided, but the amount should be similar from day to day because vitamin K affects the INR. No new painkillers, tonics, ayurvedic or herbal preparations, or antibiotics without asking the doctor - many interact with warfarin.
Come back at once for: black tarry stools or blood in the stool, red or brown urine, vomiting blood or coffee-ground material, a nosebleed that does not stop after 10 minutes of pressure, bleeding gums, unusual or large bruises, a severe headache, confusion or weakness on one side, or any cut that keeps bleeding.
Also: use a soft toothbrush and an electric razor; keep INR appointments; and turn her two-hourly, keep the sacrum clean and dry, and check the heels and back at every turn so the red area does not become an open sore.