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Can antihistamines like Cimetidine, Desloratadine and Loratadine play an integrative role in cancer cure?

Antihistamines like Cimetidine, Desloratadine and Loratadine reduce metastases and increase cancer survival

Cimetidine, or Tagamet, (an antihistamine and common heartburn remedy) can play an important part in the majority of Integrative cancer treatment programmes when having surgery. Furthermore, there is clear research showing that the use of other antihistamines like Desloratadine and Loratadine, should be considered by almost everybody who fears metastases - they actually increase cancer survival (Chris Woollams; CANCERactive).

Antihistamines stop cancer cells sticking and spreading

Let´s start with Cimetidine: Research shows this cheap antihistamine can play an important role in stopping cancer cells being ´sticky´ and clumping together thus preventing secondary tumour formation; and in stopping cancer cells sticking to other tissues thus restricting metastases. It is particularly useful in limiting cancer spread as a result of surgery or biopsy. It had some very impressive research results when used with colorectal cancer, where it greatly increases survival; and with prostate cancer. There is some evidence it might boost white cell count too.

In one research study on colorectal cancer by Matsumoto the number of people failing to live 3 years after surgery was 47 per cent. But in those that took Cimetidine, this figure fell to just 5 per cent.

Cimetidine is a cheap, out-of-patent drug. Doctors who know of its anti-cancer side effects prescribe it before, during and for up to two years after cancer surgery.

There may be better alternatives. Swedish research across a sample of 50,000 women with breast cancer showed those also taking antihistamines like Desloratadine or Loratadine increased their survival significantly.

Cimetidine reduces metastases

One step in the cancer process is the need for cancer cells to be sticky. The stickiness occurs by inflammation in the cancer cell wall. One expert described it as like having ´velcro patches´. The sticky cells survive in the blood stream by sticking to the blood vessel walls; they also use the stickiness to clump together with other cancer cells and thus start a tumour. The stickiness also holds the tumour together. The velcro-like stickiness is caused by E-selectin. 

Cimetidine is known to block E-selectin.

Cimetidine, or Tagamet, is a cheap over-the-counted medicine which was approved by the FDA back in 1977 and so is now off patent. It is a histamine receptor antagonist, and is used to treat stomach and duodenal ulcers and heartburn and indigestion. Histamines cause the stomach to produce acid and cimetidine stops this.

Cimetidine works against histamine receptor sites on the cancer cell wall. And histamines seem to be required to bind cancer cells together. 

Thus Tagamet (Cimetidine) reduces the histamine-derived inflammation of cancer cells and reduces metastases and cancer spread, the main cause of cancer death. 

Research on Cimetidine as a cancer treatment

The first report of cimetidine´s use with cancer was an article in The Lancet in 1979 (1: 882-883) which reported that it possessed anti-tumour abilities. It had been used with a lung cancer patient. Several studies with mice followed until another Lancet report showed it effective with melanoma patients, where it cleared up the ulceration of tumours.

A number of papers then appeared in the New England Journal of Medicine and The Lancet showing its effectiveness amongst patients after colorectal cancer operations, either used on its own or in conjunction with standard treatments. By 2002 the British Journal of Cancer reported a trial with 64 patients. The group without cimetidine showed a 10-year survival of 49.8, whereas the group also taking cimetidine had a 10-year survival of 84.6 per cent. In the group with the most aggressive cancers the figures were, without 23 per cent; with 85 per cent! The important conclusion was to give the drug before and during surgery.

This conclusion was reinforced by two studies one from Japan (Fujita Health University; Matsumoto; Lancet 1995; 346: 115) where the group taking cimetidine with the chemotherapy 5-FU had a 4-year survival of 96.3 per cent compared to the group on chemo only of 68.8 per cent. The cimetidine was given before the surgery. However, in a Danish study where it was started 3 weeks after surgery there was no benefit over the control group.

Cimetidine may boost immune response too

In our article, ´Can Surgery Spread Cancer?´ we looked at various ways in which surgery might cause metastatic activity. Cimetidine may in fact help in two ways  - not just by its histamine-preventing activity stopping cells clumping together, but it just may boost the immune system as well.

In 1997 the journal Cancer (80: 15-21) reported a study by Adams and Morris where again the cimetidine was given before and during colorectal surgery. They looked at white blood lymphocytes before and after the surgery. Those patients taking the cimetidine showed an improvement in lymphocyte levels in more than half the subjects, whereas the placebo boosted the levels in under a quarter of the control group. Equally important was the follow up where 3-year survival was in line with the findings at the time of surgery. It is possible that this immune response as an independent benefit. It is thought that antihistamines have a strong effect on cytokines. Other studies have looked at prostate cancer and found similar improved survival figures.

Other antihistamines, like Desloratadine and Loratadine, have been shown to increase cancer survival 

There is some concern that Cimetidine has estrogenic properties and should NOT be used with, say, ER+ breast cancer.

Given that Integrative practitioners recommend Cimetidine use before, during and for up to 2 years after surgery, if you have ER+ cancer like a breast cancer or prostate cancer, for example, this must be a concern.

Fortunately, all anti-histamines were not created equal. Cimetidine is an H2 antagonist like ranitidine.and primarily used for acid reflux. Antihistamines like Desloratadine are H1 antagonists and used for allergies.

Swedish researchers(1) looked at over 50,000 women who had ER+ Breast cancer and those who simultaneously took a second generation antihistamine. When comparing users with non-users a significant survival improvement was seen for the users of 30 per cent or more. Various antihistamines were compared and Desloratadine provided the best results; Loratadine was not far behind.  

In summary: Cheap Antihistamines reduce metastases, improve immune response and increase survival

Although the exact method of action is not clear, there is more than enough research now to suggest using these inexpensive drugs is of significant benefit to people with cancer. They reduce cancer cell ´stickyness´ and increase immune response , reduce metastases and increase survival. We believe all our readers should consider the use of these antihistamines as part of their Integrative Treatment Programme.

Even a small aspirin seems to have a similar effect in reducing inflammation on the surface of cancer cells.


Reference 1:

2. ´Can Surgery Spread Cancer´ even if you are ´only´ having a biopsy

3. Cimetidine as an effective anti-cancer drug -

4. Aspirin and cancer 


* NB. Cimetidine (Tagamet) may inhibit the action of anti-coagulent drugs - and so you should always consult your doctor before taking it. 

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