Tacrolimus

introduction

Tacrolimus is a medicine that is used to inhibit and modulate the immune system. It is widely used to inhibit transplant rejection, some autoimmune diseases, and chronic inflammatory skin diseases. The active ingredient is obtained from gram-positive bacteria of the genus Streptomyces and is structurally similar to the group of macrolide antibiotics.
Tacrolimus was first approved in 1994. Due to its immunomodulatory effect, it has since been increasingly approved for other diseases (i.a. also as eye drops and mouthwash).

Indications for tacrolimus

After oral administration (in the form of tablets) it works immunosuppressive and is used for Inhibition of transplant rejection (e.g. after kidney, liver, heart transplant) and rarely at Autoimmune reactions (e.g. Ulcerative colitis, Crohn's disease, myasthenia gravis). When applied topically on the skin (in the form of an ointment) tacrolimus works immunomodulatory and is often used at Neurodermatitis (atopic eczema). In addition, it has also been used in therapy in recent years psoriasis (chronic inflammatory skin disease) integrated.

It comes in the form of eye drops very dry eyes as part of a Keratoconjunctivitis sicca used. It is also used as a component of mouthwashes Inflammation of the lining of the mouth.

Tacrolimus for psoriasis

Psoriasis is one chronic, non-inflammatory skin disease. The body's immune system is directed against the body's own structures in the skin. As a result of the inflammation, reddish, scaly patches form on the surface of the skin, depending on the severity.

Tacrolimus is used to suppress this autoimmune reaction by changing and suppressing the immunological processes in the skin. Compared to additionally used Glucocorticoids (Cortisone) tacrolimus is characterized by a better tolerance off - there is usually no skin atrophy (thin skin) and no increase in intraocular pressure.

Read more about the here Therapy of psoriasis.

Side effects of tacrolimus

Depending on the type of application (systemic or localized) different side effects and these can occur in different degrees of severity.

With systemic use (often over a longer period of time) it can become a Damage to the kidneys (Nephrotoxicity) and one Damage to the nervous system (Neurotoxicity) come. As a result, you can neurological disorders occur (Tremors, dizziness, blurred vision, depression, insomnia). Also are high blood pressure, cramps and increased blood sugar levels possible during therapy.
There is a systemic inhibition of the immune system increased susceptibility to infection. Studies have also shown long-term use of tacrolimus by one slightly increased risk of cancer reported (above all Skin cancer) - Regular checks by a dermatologist and adequate sun protection are required. Further side effects with systemic use can be found on the package insert.

In the case of topical, i.e. local application, the affected skin area may develop in the first few days after application of tacrolimus Redness With Burn and itching come. Also a Feeling hot in the affected section of the skin is possible.

Interactions with tacrolimus

When tacrolimus is absorbed into the body, it is produced in the liver by an enzyme (CYP34A) almost completely metabolized. Since many other drugs are metabolized by the same enzyme, it can too if taken at the same time Interactions with the risk of one increased or weakened effect come. Using tacrolism after a transplant runs the risk of graft rejection.
Frequent interactions occur when combined with Johannis herbs, Carbamazepine, Barbiturates, Amiodarone, Cimetidine and some Antibiotics. Also the simultaneous supply of Grapefruit juice can have a significant effect on the active levels of tacrolimus.

Tacrolimus and alcohol- are they compatible?

If you are taking tacrolimus (systemic and topical) should completely refrain from consuming alcohol. Even very small amounts of alcohol can lead to intolerance reactions (Rash, redness, burning, itching, swelling), which are mainly in the face manifest. The symptoms usually subside a few hours after drinking alcohol.

Contraindications to tacrolimus

If you are known to have hypersensitivity or allergic reactions to tacrolimus, you should refrain from taking it and use another immunosuppressant instead. Also Intolerance to macrolide antibiotics (e.g. Erythromycin, clarithromycin) can lead to hypersensitivity reactions due to the similar structure of tacrolimus.
It should be noted that some preparations Lactose contain. In the case of carbohydrate metabolic disorders (e.g..B. Galactose intolerance, lactose intolerance) should therefore be discussed with the attending physician about the possible effects before taking tacrolimus.

Dosage of tacrolimus

When used systemically, tacrolimus is usually in the form of Tablets administered - intravenous application is also possible in exceptional cases. Depending on the half-life, a distinction is made between Retard capsules and non-retarded capsules. Retard capsules are once a day (In the morning) taken while non-retarded capsules twice daily (in the mornings and the evenings) can be taken. The exact setting of the dose depends on body weight and illness and is done by the attending physician.
When applied topically in the form of a ointment will this 1-2 times a day Applied until symptoms resolve. Use can be continued for up to a week after symptoms have resolved.

Tacrolimus levels

The drug use of tacrolimus is subject to one narrow therapeutic range. This means that even slightly increased levels of tacrolimus in the blood can lead to very serious side effects and slightly decreased levels can lead to a lack of the desired effect. The active level should therefore be set by the attending physician and regularly supervised become.

Dosage forms

Tacrolimus as an ointment / cream

Tacrolimus can be used topically in the form of an ointment or cream. It is often used for Neurodermatitis (atopic eczema), one allergic hypersensitivity reaction (Type I.), in which there is extensive reddening of the skin with severe itching in typical areas (above all in the area of ​​the great bends) is coming.
By applying an ointment, the inflammation in the skin can be selectively inhibited. In contrast to also often used for neurodermatitis Glucocorticoids (Cortisone) Therapy with tacrolimus does not lead to skin atrophy (thin skin) and no increase in intraocular pressure. The side effects are mostly limited to the skin (Redness, burning, itching), as only a very small amount gets into the bloodstream.

Tacrolimus is also increasing in recent years preventive Used in eczema therapy to reduce the number of flare-ups and to relieve the severity of each flare-up.

Tacrolimus as an eye drop

Tacrolimus can also be used as part of eye drops for very dry eyes in the context of non-infectious conjunctivitis (Keratoconjunctivitis sicca) be used. The effect is based on a lowering of the concentrations of inflammation-stimulating factors within the tear film.

Alternatively, cyclospoprin A is often used in eye drops. This is also an immunosuppressive drug that has a mechanism of action similar to that of tacrolimus. However, initial studies have shown that tacrolimus has a significantly higher potency (stronger effect) in the treatment of non-infectious conjunctivitis. However, since tacrolimus has only come onto the market in the last few years, there is still no experience of the long-term results with these eye drops.

Please also read our page What can you do with dry eyes?

Tacrolimus as a mouthwash

Also, tacrolimus can also be used at Inflammation of the lining of the mouth (Lichen planus) be used. Lichen planus is a chronic inflammation of the skin or the mucous membrane with severe itching.
Tacrolimus is often a component of mouthwashes. It has an immunomodulatory and anti-inflammatory effect, thereby leading to a Decrease in symptoms for inflammation of the oral mucosa.

Price of the different dosage forms

Tacrolimus is Prescription or prescription only available at the pharmacy. Prices between ointments (topical) and tablets (systemic) vary greatly.
Ointments containing tacrolimus in different concentrations (10-50g) are included from a price of approx 25€ to acquire. Tacrolimus preparations in the form of tablets are available in different sizes (50 or 100 capsules) to buy. The prices for a pack of 50 capsules start from approx 200€.

How tacrolimus works

Tacrolimus engages in that Activation of the immune system after recognition of foreign structures (e.g. Fragments of bacteria / viruses, transplants, and much more.)a. These structures become the T cells of the immune system presented by antigen presenting cells. As a result, important messenger substances are synthesized within the T cells (i.a. Interleukins), which are responsible for their own growth and the activation of other immune cells.

Tacrolimus acts as a Calcineurin inhibitor in T cells. Due to its fat-loving character, it binds to immunophilin within the cells, creating signal transduction pathways via calcineurin and thus the synthesis of the messenger substance Interleukin (IL-2) is inhibited. IL-2 is important for the independent activation and stimulation of the T cells, which mediate part of the immune reactions in the body. In addition, the synthesis further messenger substances inhibited the immune system.

In contrast to other immunosuppressants used, tacrolimus already takes effect after a few days. Therefore, tacrolimus is often combined with other immunosuppressants to achieve both short and long-term immunosuppressive effects.

You can also find more information about how the Immune system.