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Updated: Jan 2, 2026
Immunostimulatory Agent Evaluation: Lymphoid Tissue Extraction and Injection Route-Dependent Dendritic Cell Activation
Published on: September 16, 2018
The immunomodulatory potency of cimetidine in healthy volunteers
N H Brockmeyer1, E Kreuzfelder, N Chalabi
1Department of Dermatology, Universitätsklinikum Essen, FRG.
Insights
Cimetidine, a histamine H2 receptor antagonist, impacts the immune system. This study found dose-dependent effects on immunoglobulins, lymphocytes, and complement levels in healthy volunteers.
Area of Science:
- Immunology
- Pharmacology
Background:
- Histamine H2 receptor antagonists, like cimetidine, are used to treat acid-related disorders.
- Previous studies suggested potential immunomodulatory effects of cimetidine.
Purpose of the Study:
- To investigate the effects of a 1,600 mg daily dose of cimetidine on the immune system in healthy volunteers.
- To compare these effects with a previous study using an 800 mg dose.
Main Methods:
- 12 healthy volunteers participated in a six-week study.
- Cimetidine was administered orally at 1,600 mg/day for the first three weeks.
- Immune parameters including immunoglobulins, complement, lymphocyte subsets, and in vitro lymphocyte proliferation were assessed.
Main Results:
- Significant alterations were observed in immunoglobulin (IgG, IgA), complement (C3), B-lymphocyte, and T-helper cell counts.
- In vitro lymphocyte proliferation response to mitogens increased.
- A significant increase in CD4 cell count was noted, unlike previous findings with lower doses.
Conclusions:
- Cimetidine exhibits a dose- and time-dependent effect on the peripheral immune system.
- Immune system activation was observed at both 800 mg and 1,600 mg doses, though skin immune system reactivity differed.
- Further research is warranted to fully elucidate cimetidine's immunomodulatory mechanisms.
Abstract:
The effect of cimetidine, a histamine H2 receptor antagonist, was investigated in 12 healthy volunteers over a period of six weeks. Cimetidine was administered orally in a daily doses of 1,600 mg during the first three weeks of evaluation. Significant alterations in values of immunoglobulins (IgG, IgA), complement (C3), B-lymphocytes and T-helper cell counts were found after cimetidine intake. The in vitro lymphocyte proliferation response to plant mitogens was increased. In contrast to results obtained from a previous study with healthy volunteers who were given 800 mg cimetidine, we found no significant increase in the CD4/CD8 ratio and no decrease in the CD8 but a significant increase in the CD4 cell count. Whereas the peripheral blood immune system showed signs of immune system activation following 800 and 1,600 mg cimetidine intake, reactivity patterns of skin immune system, however, differed in both studies. The data suggests that cimetidine has a dose and time dependent effect on the immune system.
