Intended for healthcare professionals

Letters Pernicious anaemia

Pernicious anaemia: self-administration of hydroxocobalamin in the covid-19 crisis

BMJ 2020; 369 doi: (Published 16 June 2020) Cite this as: BMJ 2020;369:m2380
  1. John Warren, retired consultant physician
  1. Harlow CM17 0DX, UK
  1. jpelhamwarren{at}

Mohamed and colleagues explain well the varied presentation and diagnostic difficulties of pernicious anaemia.1 I write as a retired physician, who has had pernicious anaemia for 28 years. The authors repeat the standard guidance that maintenance treatment for patients without neurological symptoms should be 1000 μg hydroxocobalamin every three months; every two months for those with neurological symptoms. Some patients, however, myself included, experience a return of their pre-treatment symptoms before the next dose is due and are relieved by a dose of hydroxocobalamin.

I have always self-administered my injections, so for many years I have taken it once a month. The drug is inexpensive, and there are no side effects from excessive dosage. The main cost is the nurse’s time to administer it. Maintenance treatment should be given according to the guidelines or sooner if symptoms occur.

I have heard from the chair of the Pernicious Anaemia Society that, during the covid-19 crisis, many patients with pernicious anaemia are being advised by their doctors to postpone their maintenance treatment. This will expose many patients to the risk of not only unpleasant and avoidable symptoms, but also neurological damage that could become irreversible.

There is a good case for patients being taught to manage this chronic condition themselves, as do those with diabetes or asthma. Intramuscular injections are, of course. painful. As far as I know the efficacy of administering hydroxocobalamin subcutaneously has not been investigated. If this was proved to be effective, it would be more acceptable to patients and more suited to self-administration.


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