Safety of low-dose low-molecular-weight-heparins in thrombocytopenic stem cell transplantation patients: a case series and review of the literature

Few attempts have been made to examine the feasibility of safely administering low- molecular- weight- heparins ( LMWHs) in the presence of concurrent thrombocytopenia. We retrospectively investigated the safety of low-dose LMWH in BMT patients, a population at risk of bleeding. In total, 26 patients received at least one dose of low- dose enoxaparin ( ie < 1 mg/ kg/ day) during thrombocytopenia. s. c. enoxaparin 40 mg once daily was given in 85% of the cohort. The mean number of platelet days < 55 x 10(9) and < 20 x 10(9)/ l were 16.5 days ( 95% CI = 8.04 - 24.96) and 4.14 days ( 95% CI = 2.35 - 5.93), respectively. The mean number of low- dose enoxaparin administration days when platelet < 55 x 10(9) and 20 x 10(9)/ l were 9.89 days ( 95% CI = 3.26 - 16.53) and 2.25 days ( 95% CI = 0.57 - 3.93), respectively. Minor bleeding occurred in four patients ( 15%) whereas major episodes developed in two patients ( 8%). The latter two events occurred during the transition between full therapeutic ( ie 1.5 - 2 mg/ kg/ day) and low- dose enoxaparin close to the onset of thrombocytopenia. The present case series, along with the discussed literature, descriptively suggests that low- dose enoxaparin may be safely administered at a platelet count in the range of 20 and 55 x 10(9)/ l in BMT patients who weigh > 55 kg.