1. ¹Department of Pharmacy, Karmanos Cancer Institute/Harper University Hospital/The Detroit Medical Center, Detroit, MI, USA
2. ²Eugene Applebaum College of Pharmacy and Allied Health Professions, Wayne State University, 3990 John R, Detroit, MI, USA
3. ³Bone Marrow Transplantation Service, Karmanos Cancer Institute, School of Medicine, Wayne State University, Detroit, MI, USA
4. ⁴Biostatistics Core, Karmanos Cancer Institute, Wayne State University School of Medicine, Detroit, MI, USA

Correspondence: Dr RB Ibrahim, Department of Pharmacy, Harper University Hospital, The Detroit Medical Center, 3990 John R, Detroit, MI 48201-2020, USA. E-mail: ribrahim@dmc.org

Received 25 October 2004; Accepted 25 January 2005; Published online 11 April 2005.

Abstract

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 <55 10⁹ and <20 10⁹/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 <55 10⁹ and 20 10⁹/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 55 10⁹/l in BMT patients who weigh >55 kg.