Cimetidine: a review of the recent developments and reports in cutaneous medicine

Cimetidine, approved by the FDA for inhibition of gastric acid secretion, has been advocated for a number of dermatological diseases. The cutaneous uses and immunological effects of cimetidine have been actively studied over the past few years, and this review summarizes the literature accumulated since 1997.

Cimetidine in colorectal cancer--are the effects immunological or adhesion-mediated?

British Journal of Cancer (2002) 86, 159–160. DOI: 10.1038/sj/bjc/6600097www.bjcancer.com

© 2002 The Cancer Research Campaign

Pilot study--cimetidine enhances lymphocyte infiltration of human colorectal carcinoma: results of a small randomized control trial

BACKGROUND

Cimetidine preserves postoperative immune function and inhibits the growth of some cancers. In this study, the effect of cimetidine on the local immune response to colorectal carcinoma was investigated.

METHODS

Forty-two patients scheduled for elective resection of colorectal carcinoma were randomized either to receive cimetidine for 1 week perioperatively or to act as controls. A lymphocyte density of 50 cells per high-power field (approximately 50% of the tumor/tissue interface) was considered a positive response. Patient survival was determined by Kaplan-Meier life table analysis. The effects of histamine and cimetidine on normal subject lymphocyte function was determined in a mitogen-stimulated proliferation assay.

RESULTS

A positive lymphocyte response was observed in 5 of 24 control carcinoma patients (21%) and 10 of 18 cimetidine-treated carcinoma patients (56%) (P = 0.03). The presence of a lymphocyte response correlated with a better survival (P = 0.02). Histamine had an inhibitory effect on lymphocyte proliferation with a median effective dose of 5 x 10(-7) M. Cimetidine antagonized this effect with a negative logarithm of the cimetidine molar concentration required to reduce the effect of histamine in half of 6.55.

CONCLUSIONS

Histamine inhibits normal lymphocyte function, antagonized by cimetidine at a histamine type 2 receptor. Cimetidine increases lymphocyte infiltration of primary colorectal carcinoma, possibly by overcoming the immunosuppressive effects of high local histamine concentrations. The presence of a local lymphocyte response correlates with an improved 3-year survival.

Severe duodenal candidiasis in a patient with IgA deficiency and T cell defects

Candida albicans was found to repeatedly colonise and invade the duodenal ulcer base in a 45 years old otherwise healthy patient receiving H2 receptor antagonists for a prolonged period. He had no delayed hypersensitivity to Candida skin test, and had T cell deficiency, abnormality in T cell blast transformation, defective macrophage migration inhibition factor (MIF) and IgA hypogammaglobulinemia. When treated with ketoconazole alone his ulcer healed completely. Ulcer scar biopsy and aspirates revealed no Candida and anti candidal antibodies disappeared from his serum. His T cell blastoid transformation, MIF and skin DTH to Candida were restored to normal levels, but IgA levels remained unchanged. Thus H2 receptor antagonists probably caused abnormalities in T helper cells leading to lymphokine unresponsiveness and subsequently loss of cellular immunity to candidal antigen. This combined with prior IgA immunodeficiency resulted into severe invasive candidiasis.

Immunomodulatory properties of cimetidine in ARC patients

The immunomodulatory potency of cimetidine, a histamine H2 receptor antagonist, was investigated in 33 AIDS-related complex (ARC) patients performing detailed immunological and clinical evaluations. Cimetidine was administered orally in daily doses of 1200 mg for a period of 5 months with an interruption of therapy after the first 3 months for an interval of 3 weeks. Significant (P less than 0.05) elevations of immunoglobulins (IgG, IgA), complement C4, B-lymphocytes, and OKT4+ (helper/inducer) cells were found after cimetidine intake. The in vitro lymphocyte proliferative response to plant mitogens was significantly increased, and the in vivo cell-mediated hypersensitivity reaction assessed by intradermal application of seven recall antigens improved significantly. These effects were both reversible with the discontinuation of cimetidine and reproducible with repeated administration of the drug. Clinical data such as performance status, body weight, and fever were influenced favorably (P less than 0.05) by cimetidine. The frequency of diarrhea and the lymph node size were also diminished significantly. The data suggest that cimetidine may at least partially restore immunofunctions in AIDS-related complex.

Method for detection of antibody against low molecular weight antigen (hapten)--production and detection of antibody against histamine H2 receptor of antibody against histamine H2 receptor antagonist "Famotidine"

Antibodies against histamine H2-receptor antagonist "Famotidine (FAMO)", molecular weight 337, chemical name; N-sulfamoyl-3-(2-guanidinothiazol-4-ylmethylthio) propionamide, were produced by subcutaneously injecting rabbits with an albumin and FAMO conjugate covalently bound with 1-ethyl-3-(3-dimethyl-amino-propyl) carbodiimide (ECDI). Two new detection systems for antibody titration were developed and employed. In one method, the antigen FAMO was tagged to sheep red blood cells (SRBC) and analysed qualitatively by a fluorescence activated cell sorter (FACS) using a second fluorescence isothiocyanate (FITC) labeled antibody. In the other method, CH-Sepharose beads were employed in place of SRBC and Horse Radish Peroxidase (HRP) was labeled to the second antibody instead of FITC used in the former method. HRP of the immune complex was colorimetrically measured with DAB-H2O2 to analyse the fine antibody titer. These high sensitive detection methods revealed the existence of IgG type of FAMO antibody. The detection sensitive detection methods revealed the existence of IgG type of FAMO antibody. The detection sensitivity was approximately 50 to 100 times higher in the later method with HRP than in the former. Furthermore these two methods could be deemed to be a good model system for a receptor assay.

Cimetidine-induced hemolytic anemia: the fallacy of clinical associations

Two patients developed hemolytic anemia while taking cimetidine. Neither patient was taking other drugs known to cause hemolytic anemia. In both, the hemolytic anemia resolved after the drug was stopped. In one patient, the direct antiglobulin (Coombs') test was strongly positive when the hemolytic anemia was recognized and became only weakly positive as the hemolysis subsided. However, serologic studies for antidrug antibodies yielded negative results in both patients; readministration of cimetidine for 55 days in patient 1 and for more than 24 months in patient 2 did not cause recurrence of hemolysis. We conclude that we cannot incriminate cimetidine as the cause of the hemolytic anemia in either of our patients. These findings emphasize that a temporal association of drug administration and hemolytic anemia is not proof of a cause-effect relationship and that reports of drug-related adverse hematologic effects must be interpreted with caution.

Cimetidine and renal allograft rejection

Cimetidine, an H2 receptor antagonist, has gained acceptance as a drug capable of preventing gastroduodenal complications in renal transplant recipients. In several reports, cimetidine's immunoregulatory role has been questioned and its possible interference with graft acceptance has been observed. Two kidney allograft recipients are reported here, in whom cimetidine administration was associated with acute graft deterioration, which was completely reversed when the H2 receptor blocker therapy was discontinued. The observations support the view that the drug has an immunological, rather than nephrotoxic, effect. Caution should be exerted, at this stage, with respect to the use of cimetidine in renal transplant recipients.

Cimetidine and the immune response. I. In vivo augmentation of nonspecific and specific immune response

Cimetidine is a commonly prescribed histamine antagonist useful in the treatment of peptic ulcer disease. Histamine receptors are found on suppressor T cells and therefore we expected to observe enhanced immune responsiveness in animals treated with this drug. Mice given daily subcutaneous injections of cimetidine (25 or 100 mg/kg) were found to produce approximately twice as much specific antibody in response to tetanus toxoid immunization. Furthermore, mitogen-stimulated splenocytes from cimetidine-treated animals proliferated to a greater extent and produced more immunoglobulin in vitro than controls. These observations offer direct in vivo evidence for immunomodulation by cimetidine.

Cimetidine, posttransplant peptic ulcer complications, and renal allograft survival: a clinical and investigational perspective

Upper gastrointestinal (G) tract complications have been a substantial cause of death following renal transplantation. Cimetidine, an H2 receptor antagonist, has been used in the posttransplant period to decrease this hazard. However, H2 receptor antagonists may enhance the immune response and be deleterious for the graft. The magnitude of the hazard of upper GI tract complications after renal transplantation was determined by reviewing 200 renal transplants. The effect of cimetidine treatment on the survival of canine renal allografts was investigated. The upper GI tract complication rate was 1.5% with one related death (0.5%). Treatment of dogs with cimetidine shortened the survival time of renal allografts (18.2 +/- 5.5 [SE] days to 12.5 +/- 2.2 days). Because upper GI tract complications are not a major hazard and H2 receptor antagonist therapy may decrease the survival of dog renal allografts, we believe prophylactic use of cimetidine is not indicated.

Effect of histamine H2-receptor antagonists on delayed hypersensitivity

The delayed skin-test response to four antigens was assessed before and after 6 weeks' cimetidine therapy in patients with duodenal-ulcer disease. In the eight patients who received cimetidine there was a significant increase in both erythema and induration after six weeks' cimetidine therapy. In contrast, the intensity of delayed-hypersensitivity reactions at 6 weeks was not increased in eight control patients who did not receive cimetidine. These studies indicate that therapy with an H2-receptor antagonist may be associated with an augmentation of delayed hypersensitivity responses.