Which drugs belong to the immunosuppressive drugs?

Many different substances can be summarized under the term immunosuppressants. They act via different mechanisms on the different components of the immune system and are therefore divided into different groups. Probably the most frequently used group are the glucocorticoids.

Furthermore, calcineurin inhibitors and mTOR inhibitors are used as immunosuppressants. These substances exert their effect by inhibiting cellular signaling pathways. Furthermore, cytostatic agents with methotrexate as their main agent are used.

Furthermore, monoclonal antibodies or biologicals, which are produced in the laboratory, belong to the large group of immunosuppressive drugs. In the following, the already mentioned immunosuppressants with the corresponding active substances are listed:

Calcineurin inhibitors: Ciclosporin A and Tacrolimus belong to the calcineurin inhibitors. Calcineurin is an enzyme in T lymphocytes that controls the immune response of the T helper cells.
Ciclosporin is obtained from a tubular fungi, Tacrolimus from a bacterium called Streptomyces. Tacrolimus has a stronger effect than Ciclosporin. and Ciclospoprin A.
Cytostatic drugs: These drugs are actually used in cancer therapy because they inhibit cell division.
If they are used as immunosuppressants, the doses are much lower than in cancer therapy. Possible substances are cyclophosphamide, azathioprine and methotrexate.
Glucocorticoids: These actually body-own hormones are used for the therapy of many diseases, for example the rheumatic diseases. In addition to the natural glucocorticoids, there are also many synthetically produced preparations that have the same effects.
They have anti-inflammatory and immunosuppressive effects.
Mycophenolate Mofetil: This drug inhibits the proliferation of special immune cells called lymphocytes.
Sirolimus: This immunosuppressive agent also inhibits the proliferation of lymphocytes, but targets a different site than mycophenolate mofetil.
Biologicals: There are specific antibodies for many targets in the immune system, which can be specifically eliminated by application. Due to biotechnological production, they are usually very expensive, but due to their specific effect, they can significantly improve the success of treatment when other immunosuppressive drugs have no effect.

Methotrexate (MTX) belongs to the antimetabolites, more precisely to the folic acid analogues. The substance accumulates in the cells and thus interferes with dihydrofolate reductase.

In a functioning state, this enzyme produces tetrahydrofolic acid, an extremely important building block for the production of purine molecules, which in turn are essential for the production of DNA. While methotrexate is used in low doses for the treatment of autoimmune diseases, it is used in high doses in tumor therapy and is usually quite effective. The disadvantage of using this substance is the side effects.

Since Methotrexate is excreted via the kidneys, in the worst case, kidney failure can occur. The substance also has an extremely toxic (poisonous) effect on the bone marrow. Interstitial pneumonia is a common side effect caused by Methotrexate. Interstitial pneumonia means an inflammation of the lung connective tissue. Lung fibrosis, i.e. the increasing transformation of functioning lung tissue into non-functional connective tissue through chronic inflammatory processes, is the worst possible consequence of such interstitial pneumonia.