With the increasing use of tenofovir disoproxil in the management of HIV and hepatitis B, serious adverse effects, such as renal dysfunction, will inevitably increase in frequency. We describe a case of a patient presenting with hypophosphataemia suggestive of Fanconi's syndrome, but in fact explicable by simple vitamin D deficiency. This emphasizes that while monitoring for adverse effects is recommended, physicians must consider all alternative causes for biochemical abnormalities prior to discontinuing tenofovir and delaying appropriate management.
BrookMG, GilsonR, WilkinsE, BHIVA Hepatitis Coinfection Guidelines Committee. British HIV Association guidelines on HIV and chronic hepatitis: coinfection with HIV and hepatitis B virus infection. HIV Med2005;6(Suppl 2):84–95
2.
TanLK, GilleeceY, MandaliaS, Reduced glomerular filtration rate but sustained virologic response in HIV/hepatitis B co-infected individuals on long-term tenofovir. J Viral Hepat2009;16:471–78
3.
MathewG, KnausSJ. Acquired Fanconi's syndrome associated with tenofovir therapy. J Gen Intern Med2006;21:C3–5
4.
PerrotS, AslangulE, SzwebelT, Bone pain due to fractures revealing osteomalacia related to tenofovir-induced proximal renal tubular dysfunction in a human immunodeficiency virus-infected patient. J Clin Rheumatol2009;15:72–74
5.
ParsonageMJ, WilkinsEG, SnowdenN, The development of hypophosphataemic osteomalacia with myopathy in two patients with HIV infection receiving tenofovir therapy. HIV Med2005;6:341–46
6.
EarleKE, SeneviratneT, ShakerJ, ShobackD. Fanconi's syndrome in HIV+ adults: report of three cases and literature review. J Bone Miner Res2004;19:714–21
7.
JamesCW, SteinhausMC, SzaboS, DressierRM. Tenofovir-related nephrotoxicity: case report and review of the literature. Pharmacotherapy2004;24:415–18
MoeSM. Disorders involving calcium, phosphorus, and magnesium. Prim Care2008;35:215–37, v–vi
10.
HolickMF. Vitamin D deficiency. N Engl J Med2007;357:266–81
11.
FuxC, RauchA, SimcockM, Swiss HIV Cohort Study. Tenofovir use is associated with an increase in serum alkaline phosphatase in the Swiss HIV Cohort Study. Antiviral Ther2008;13:1077–82
12.
FisherL, FisherA. Vitamin D and parathyroid hormone in outpatients with noncholestatic chronic liver disease. Clin Gastroenterol Hepatol2007;5:513–20
13.
WelzT, ChildsK, IbrahimF, Efavirenz use is associated with severe vitamin D deficiency in a large, ethnically diverse urban UK HIV cohort. 5th International AIDS Society Conference on HIV Pathogenesis, Treatment, and Prevention (IAS 2009). Cape Town, South Africa, 2009: Abstract TUPEB186
