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.