Case 30-2004: A Woman with Paresthesias

To the Editor: In reference to the discussion of pernicious anemia in Case 30-2004 (Sept. 23 issue), 1 the practice in the United Kingdom for many years has been a regimen of four intramuscular injections of 1000 μg of hydroxocobalamin (an injectable form of vitamin B 12 ) per year in patients with pernicious anemia, usually given every three months. This treatment follows initial therapy comprising four or five 1000-μg doses given over a period of approximately four weeks. That this constitutes adequate replacement therapy is evident from widely shared experience. Pharmacokinetic evidence provides a sound basis for this practice; 500 . . .