How we deliver healthcare is constantly changing, but a new case study by Emma Woo (IMP Class of 2021) shows the importance of remembering the past.
In “Incapacitating Pain from Tenofovir Induced Hypophosphatemic Osteomalacia in a Hemophilia Patient – A Case Report,” published in the Canadian Journal of Pain, Emma details the search for the cause of incapacitating pain in a patient with hemophilia, a rare disorder in which one’s blood doesn’t clot normally.

Emma Woo (IMP Class of 2021)
Pain is common in individuals with hemophilia, and it is normally the result of joint bleeds that may cause progressive joint damage. That was not case here. The ultimate diagnosis was that one of this patient’s antiviral medications, Tenofovir, caused kidney-related electrolyte imbalances, weakening their bones and causing pain (i.e., hypophosphatemic osteomalacia secondary to Fanconi Syndrome). The patient took this medication to treat HIV, which they contracted along with hepatitis C through a blood transfusion, the main treatment for their hemophilia.
While it is uncommon for patients with hemophilia – or anyone receiving blood transfusions for that matter – to contract bloodborne illnesses these days, blood transfusions were not always subject to as rigorous testing as they are now.
Emma says this case shows how important it is to not assume the cause of pain in hemophilia patients. There should be a focus on discovering the cause of the pain, as well as advancements in how we describe, monitor, and treat it. In her paper, she writes that diagnosis should begin with taking a thorough history that includes past treatments and medications.
“A single case report can reflect past, and inform future public health practices,” she explains. “Recognizing the demographic and epidemiologic realities of past decades can dramatically inform one’s differential for common presentations.”
“Looking forward – especially in light of the COVID-19 epidemic during which there have been several antiviral trials – this case serves to acknowledge the importance of knowing antiviral side-effects,” she adds.
Since this patient’s diagnosis, the patient has stopped taking Tenofovir and they have returned to their baseline. There have also been updated guidelines to ensure regular electrolyte screening to monitor for Fanconi syndrome in patients on antiretrovirals for HIV.
“This was a great student learning case, involving multiple systems and requiring an awareness of hematological pathology, renal function, drug toxicity, and to a certain degree, epidemiology,” says Emma. “This case also piqued my interest in part because of the diagnostic delay. The exercise in acknowledging how systems can improve is very compelling and is one of the reasons why I find clinical work so exciting.”