§ Mrs. Renée Short
asked the Secretary of State for Social Services (1) what adverse reactions have been reported to the Committee on Safety of Medicines in connection with the stomach drug cimetidine;
(2) if he is satisfied that the drug cimetidine is safe; and what studies have been carried out to test whether its use is linked to the risk of development of stomach cancer;
(3) what evidence the Committee on Safety of Medicines has that the drug cimetidine may be linked to the risk of development of stomach cancer; and what action is being taken;
(4) what are the permitted uses of the drug cimetidine in the United Kingdom.
§ Dr. Vaughan
[pursuant to his reply, 27 January, c. 389]: Cimetidine is licensed in the United Kingdom for the treatment of duodenal ulceration and benign gastric ulceration, recurrent and stomal ulceration, reflux oesphagitis and other conditions where reduction of gastric acid secretion is likely to be beneficial; it is also recommended in the management of the Zollinger-Ellison syndrome.
Safety tests in animals including conventional carcinogenicity tests have failed to establish any direct link between cimetidine and the development of stomach cancer. The Committee on Safety of Medicines (CSM) has however, been aware for some time of scientific hypotheses that such an association could exist and 512W therefore is actively monitoring research in this field. It hopes to be able to undertake a comprehensive review of all the available evidence on this matter in the near future.
The CSM has received a total of 2,459 reports of suspected adverse reactions associated with treatment with cimetidine though it must not be assumed these events were caused by the drug. The most commonly reported adverse effects relate to the central nervous system—exempli gratia headache, dizziness—skin disorders, psychiatric disorders—exempli gratia depression—liver disorders, abdominal pain, nausea and diarrhoea. Twenty one reports of stomach cancer have been received. It is stressed that these do not in themselves provide any evidence of a causal relationship since it is believed that they are only associated in time with treatment with cimetidine; in the majority of cases it is probable that the cancer existed prior to the commencement of treatment with cimetidine.
In considering any possible risk, associated with cimetidine it is important to bear in mind that the conditions for which cimetidine is licensed are usually serious and very painful and alternative drug therapies or surgery carry their own risks. In the circumstances it is the view of the CSM and the Department's medical advisers that the use of cimetidine should continue to be so licensed unless fresh evidence arises and that patients should continue to take cimetidine in accordance with their doctors' advice. To assist doctors the company has prepared a very informative booklet on the safety profile of cimetidine which discusses at length the question of gastric cancer.