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

Geriatric patients with a cobalamin deficiency are usually treated with int ramuscular vitamin cobalamin injections. This treatment may be painful and requires skilled personnel. This study was designed to investigate the abso rption of intranasally applied hydroxocobalamin in cobalamin-deficient geri atric patients. Twenty-one geriatric patients with plasma cobalamin concent rations of 150 pmol/L or less were recruited. Geriatric patients were defin ed as being greater than or equal to 65 years of age and having multiple ph ysical, mental, or social problems. A dose of 1,500 mug hydroxocobalamin wa s applied intranasally for 4 weeks: the first week daily and the next 3 wee ks once a week. Baseline plasma cobalamin concentration was 120 +/- 30 pmol /L (mean +/- SD). The maximum plasma cobalamin concentration, 1,300 +/- 1,1 00 pmol/L, was reached after 1 week of daily hydroxocobalamin administratio n. After 4 weeks of treatment a steady state was reached, with a mean plasm a cobalamin concentration of 370 +/- 140 pmol/L. No side effects were noted . Intranasal application of hydroxocobalamin in cobalamin-deficient geriatr ic patients is well tolerated and results in a steady state within the rang e of normal plasma cobalamin concentrations. Drug Dev. Res. 51:197-199, 200 0. (C) 2001 Wiley-Liss, Inc.