New frontiers with bemiparin: use in special populations.

Special populations are rarely included in conventional clinical trials and subsequently there is a lack of guidance on the appropriate treatment regimens to use. This paper reviews data on the use of bemiparin in such populations, including the elderly, those with renal impairment, pregnant women and children. Pharmacokinetic data from elderly patients suggest that bemiparin is also safe in this patient population. There was no evidence of the accumulation of bemiparin after repeated prophylactic doses. At therapeutic doses, there was no significant difference in pharmacokinetic profile between groups. There is no need for dose adjustment of bemiparin in the elderly, either during prophylaxis or during treatment. Data from another pharmacokinetic study showed that bemiparin at prophylactic doses is safe in patients with mild to moderate renal impairment. In general, no dose adjustment was required in patients with mild to moderate renal impairment when bemiparin is used as therapy or prophylaxis. To date, bemiparin has not been tested in patients with severe renal impairment; therefore, conclusions on the safety of bemiparin in patients with severe renal failure cannot be drawn at present. Although there are no published data on the use of bemiparin in pregnant women, promising anecdotal data are beginning to emerge. Current guidelines recommend low molecular weight heparins (LMWH) for the treatment of venous thromboembolism (VTE) in pregnant women, with treatment maintained at therapeutic doses throughout pregnancy. Anticoagulation should continue for 6 weeks or more post-partum and should be maintained for 3 months or more after diagnosis of the VTE event. Monitoring of pregnant women receiving LMWH is not necessary, except in those at high risk. A case report describing the treatment of a neonate with renal vein thrombosis showed that 2 months' treatment with bemiparin followed by 10 months' prophylaxis was effective and safe. These data suggest that bemiparin may play a role in the treatment of VTE in paediatric patients.