Intranasal hydroxocobalamin administration: an attractive alternative for intramuscular cobalamin injections in geriatric patients

Geriatric patients with a cobalamin deficiency are usually treated with intramuscular vitamin cobalamin injections. This treatment may be painful and requires skilled personnel. This study was designed to investigate the absorption of intranasally applied hydroxocobalamin in cobalamin-deficient geriatric patients. Twenty-one geriatric patients with plasma cobalamin concentrations of 150 pmol/L or less were recruited. Geriatric patients were defined as being ≥65 years of age and having multiple physical, mental, or social problems. A dose of 1,500 μg hydroxocobalamin was applied intranasally for 4 weeks: the first week daily and the next 3 weeks once a week. Baseline plasma cobalamin concentration was 120 ± 30 pmol/L (mean ± SD). The maximum plasma cobalamin concentration, 1,300 ± 1,100 pmol/L, was reached after 1 week of daily hydroxocobalamin administration. After 4 weeks of treatment a steady state was reached, with a mean plasma cobalamin concentration of 370 ± 140 pmol/L. No side effects were noted. Intranasal application of hydroxocobalamin in cobalamin-deficient geriatric patients is well tolerated and results in a steady state within the range of normal plasma cobalamin concentrations. Drug Dev. Res. 51:197–199, 2000. © 2001 Wiley-Liss, Inc.