A Double-Dose Dispensing Error in a Patient Living Alone
Your clinic's regular pharmacist is on leave and a locum covers Monday. At 6pm you take a call from the locum: Mrs Ng, 78, who normally takes amlodipine 5 mg daily for hypertension, was given a box of amlodipine 10 mg tablets labelled "take one tablet daily". She has already taken two doses. She lives alone and has mild cognitive impairment (Montreal Cognitive Assessment score 22); her only caregiver is a domestic helper whose English is limited. Her other medicines are perindopril 4 mg, atorvastatin 20 mg and occasional furosemide 40 mg, and she had a fall two months ago. The locum asks whether to "just swap the box and not mention it, to avoid worrying her" - nobody else noticed, and the mistake only surfaced during a stock count.
1. What are your immediate clinical and organisational actions tonight?
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Assess first, discuss later. Doubling amlodipine for two doses in a 78-year-old on perindopril is unlikely to be catastrophic but is not trivial: the risk is symptomatic hypotension, dizziness and falls - and she has fallen recently. I would arrange a same-evening home visit or have her brought in, with BP and heart rate measured seated and standing, a check for dizziness, oedema and confusion, and a review of what she has actually taken and when.
Treatment. Usually none beyond withholding nothing and monitoring, but if she is symptomatic and hypotensive, stop the amlodipine for 24–48 hours on medical advice and recheck. Perindopril may need temporary interruption if she becomes dehydrated. Advise lying down if dizzy and how to call for help.
Remove the wrong tablets. Retrieve the mislabelled box tonight - a box with the wrong label in a cognitively impaired patient's home is an ongoing hazard. Re-dispense correctly with a clear, large-print label and, ideally, a pictorial dose aid.
Communicate with the caregiver. The domestic helper is the person who will actually supervise the doses, so she needs the message in simple English with a written card, and the family (son or daughter) should be contacted by phone tonight with consent.
Document fully in the clinical record: the error, the two doses, the assessment, the plan and the follow-up call.
Report. File an internal incident report the same night - not to blame the locum, but because the underlying cause is a locum covering a dispensing system without a second check. Consider whether the error meets the threshold for external reporting.
2. The locum suggests concealing the error to avoid distress. How do you handle the disclosure, and what system changes would you put in place?
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Why disclosure is not optional. The patient has been exposed to a medicine she did not expect; if she becomes dizzy or falls tonight and no one knows why, the harm is compounded. Concealment also corrodes the trust the clinic depends on, and it denies her the information she needs to protect herself. She has the right to know, and the apology must come from the clinic, not the locum alone.
How to disclose. Face to face, with the locum present, in simple English or her own language, with the helper present: what happened, what it means for her, what we have done, and what to watch for. Say sorry plainly - an apology is not an admission of legal liability and is expected of any healthcare professional. Check understanding with teach-back ("Can you tell me what you'll do if you feel dizzy?"). Avoid minimising language like "just a small mix-up".
System changes - the real lesson. The locum dispensed without a second check; the label and the box were not compared; the patient's cognitive impairment was not flagged in the dispensing system. Practical fixes: an independent second check comparing tablet strength on the box against the prescription before handover; a visual "high-risk patient" flag for patients with cognitive impairment living alone; pre-printed large-print labels; a rule that locums do not dispense unaccompanied; and a review of staffing over the holiday period when the regular pharmacist is away. Audit the locums' dispensing for the next month.
Follow-up. Telephone or review the patient within 48 hours, record BP, and close the loop on the incident report at the practice meeting.