Erythrocyte-mediated delivery of dexamethasone in patients with chronic obstructive pulmonary disease

Human erythrocytes from ten patients with chronic obstructive pulmonary dis ease (COPD) were loaded with increasing amounts of dexamethasone 21-phospha te and were re-infused into the original donors. Drug-loaded erythrocytes a cted as circulating bioreactors, converting the non-diffusible dexamethason e 21-phosphate into the diffusible dexamethasone. Pharmacokinetic analyses on these patients showed that a single administration of drug-loaded erythr ocytes was able to maintain detectable dexamethasone concentrations in bloo d for up to seven days. This continuous release of dexamethasone was parall eled by the suspension of beta (2)-agonist and oral corticosteroid treatmen ts by all of the patients,Thus dexamethasone 21-phosphate-loaded erythrocyt es are safe carriers for corticosteroid analogues and are a useful alternat ive to frequent oral or inhaled drugs in elderly patients with COPD.