A Case of a Dispensing Error Causing Iatrogenic Orthostatic Hypotension

  • Kenneth Lam University of Toronto
  • Ann Leung St. Michael's Hospital
  • Trevor Jamieson University of Toronto
Keywords: Drug-Related Side Effects and Adverse Reactions, Orthostatic hypotension, Medication Reconciliation, Medication errors


This is a case report of a patient with Parkinson’s disease and orthostatic hypotension who presented with increasing falls. We discovered that there had been a dispensing error where amiloride (Midamor®) was supplied instead of midodrine. The error was uncovered during a medication reconciliation by our pharmacist; the pharmacist noted that the pills were stamped with the wrong number and the patient’s caregiver noted that at the last refill they had, indeed, changed shape. Beyond providing the impetus for a review of orthostatic hypotension, this case also highlights an easily missed cause of an adverse drug event, and highlights the importance of the multidisciplinary team and engaged patients and caregivers. 

Author Biographies

Kenneth Lam, University of Toronto
Kenneth is a third year resident in Internal Medicine at the University of Toronto and will be completing his specialty training in Geriatrics at University of Toronto.
Ann Leung, St. Michael's Hospital
Ann Leung is a clinical pharmacist in the cardiac ICU at St. Michael's Hospital.
Trevor Jamieson, University of Toronto
Trevor Jamieson is an Assistant Professor at the University of Toronto and a member of the Division of General Internal Medicine at St. Michael's Hospital.


Freeman R, Wieling W, Axelrod FB, et al. Consensus statement on the definition of orthostatic hypotension, neurally mediated syncope and the postural tachycardia syndrome. Clin Auton Res. 2011;21(2):69-72. doi:10.1007/s10286-011-0119-5. https://link.springer.com/article/10.1007%2Fs10286-011-0119-5. Accessed 19 Apr 2017.

Finucane C, O'Connell MDL, Fan CW, et al. Age-Related Normative Changes in Phasic Orthostatic Blood Pressure in a Large Population Study: Findings From The Irish Longitudinal Study on Ageing (TILDA). Circulation. 2014;130(20):1780-1789. doi:10.1161/CIRCULATIONAHA.114.009831. http://circ.ahajournals.org/content/circulationaha/early/2014/10/02/CIRCULATIONAHA.114.009831.full.pdf. Accessed 19 Apr 2017.

Low PA. Prevalence of orthostatic hypotension. Clin Auton Res. 2008;18(S1):8-13. doi:10.1007/s10286-007-1001-3. https://link.springer.com/article/10.1007/s10286-007-1001-3. Accessed 19 Apr 2017.

Rutan GH, Hermanson B, Bild DE, Kittner SJ, LaBaw F, Tell GS. Orthostatic hypotension in older adults. The Cardiovascular Health Study. CHS Collaborative Research Group. Hypertension. 1992;19(6 Pt 1):508-519. http://hyper.ahajournals.org/content/hypertensionaha/19/6_Pt_1/508.full.pdf. Accessed 19 Apr 2017.

Gupta V, Lipsitz LA. Orthostatic Hypotension in the Elderly: Diagnosis and Treatment. Am J Med. 2007;120(10):841-847. doi:10.1016/j.amjmed.2007.02.023. https://www.researchgate.net/profile/Lewis_Lipsitz/publication/5941360_Orthostatic_Hypotension_in_the_Elderly_Diagnosis_and_Treatment/links/09e41509a68e1050a1000000.pdf. Accessed 19 Apr 2017.

Logan IC, Witham MD. Efficacy of treatments for orthostatic hypotension: a systematic review. Age Ageing. 2012;41(5):587-594. doi:10.1093/ageing/afs061. https://academic.oup.com/ageing/article/41/5/587/47111/Efficacy-of-treatments-for-orthostatic-hypotension. Accessed 19 Apr 2017.

Shibao C, Lipsitz LA, Biaggioni I, Group ASOHW. Evaluation and treatment of orthostatic hypotension. J Am Soc Hypertens. 2013;7(4):317-324. doi:10.1016/j.jash.2013.04.006. http://www.sciencedirect.com/science/article/pii/S1933171113000740. Accessed 19 Apr 2017.

Pirmohamed M, James S, Meakin S, et al. Adverse drug reactions as cause of admission to hospital: prospective analysis of 18 820 patients. BMJ. 2004;329(7456):15-19. doi:10.1136/bmj.329.7456.15. http://www.bmj.com/content/329/7456/15?variant=full. Accessed 19 Apr 2017.

Splawski J, Minger H. Value of the Pharmacist in the Medication Reconciliation Process. P&T. 2016;41(3):176-178. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4771087. Accessed 19 Apr 2017.

James KL, Barlow D, McArtney R, Hiom S, Roberts D, Whittlesea C. Incidence, type and causes of dispensing errors: a review of the literature. Int J Pharm Pract. 2009;17(1):9-30. doi:10.1211/ijpp/17.1.0004. http://onlinelibrary.wiley.com/doi/10.1211/ijpp.17.1.0004/full. Accessed 19 Apr 2017.

How to Cite
Lam, K., Leung, A., & Jamieson, T. (2018). A Case of a Dispensing Error Causing Iatrogenic Orthostatic Hypotension. Canadian Journal of General Internal Medicine, 13(2). https://doi.org/10.22374/cjgim.v13i2.202
Case Report