Vancomycin has been reported to cause clinically relevant thrombocytopenia. (1-4) However, the true
frequency with general use in the population is not known. An evaluation
of patients who developed thrombocytopenia while receiving vancomycin most
commonly developed it after receiving intravenous vancomycin for at least 6
days. (4) The average reduction from baseline in platelets was approximately 93%.
The average nadir in the platelet count during the episode of thrombocytopenia
was 13,600 per mm3. (4)
What is the mechanism by which vancomycin can cause thrombocytopenia?
- It
appears that some patients will develop antibodies specific to glycoprotein
IIb/IIIa on the platelet surface.
- The type of antibodies formed seem to
be predominately IgG antibodies, but can also be a combination of IgM only or a
combination of IgG and IgM antibodies. (4) The antibodies formed in the
presence of vancomycin appear to function similar to antibodies induced by
quinine.
Are
patients who develop vancomycin-induced thrombocytopenia at increased risk for
bleeding?
-
Yes, of the small number of patients who do develop this drug induced
condition, about 34% of those patients experienced clinically relevant
bleeding.
- This risk for bleeding is most likely due to the average nadir
in the platelet count during the episode of thrombocytopenia being around
13,600 per mm3. (4)
Does
the platelet count recover after stopping the vancomycin?
-
Upon discontinuation of the vancomycin, it took about 7 days before the
platelet count returned to 150,000 per mm3. (4) While the majority of patients
developed the thrombocytopenia after 6 days of vancomycin use, there were a few
patients who developed severe thrombocytopenia within 24-48 hours.
- Unfortunately, these patients are at increased risk for bleeding and should be
monitored for.
References:
- Christie
DJ, van Buren N, Lennon SS, Putnam JL.
Vancomycin-dependent antibodies associated with thrombocytopenia and
refractoriness to platelet transfusion in patients with leukemia. Blood
1990;75:518-23.
- Kuruppu JC, Le TP, Tuazon CU. Vancomycin-associated
thrombocytopenia: case report and review of the literature. Am J Hematol
1999;60:249-50.
- Marraffa J, Guharoy R, Duggan D, Rose F, Nazeer S.
Vancomycin-induced thrombocytopenia: a case proven with rechallenge.
Pharmacotherapy 2003;23:1195-8.
- Von Drygalski A, Curtis BR, Bougie DW, McFarland JG, Ahl
S, Limbu I, Baker KR, Aster RH. Vancomycin-induced immune
thrombocytopenia. N Engl J Med 2007;356:904-10.
