Protopic for Vitiligo

What is Protopic?

Protopic is a topical formulation of tacrolimus used for treating eczema and vitiligo. This ointment is sold by Astellas Pharma.

It is available in 2 strengths: 0.1% for adults and teenagers who are 16 and older as well as 0.03% for children over the age of 2. Besides tacrolimus, the active ingredient, Protopic contains inactive ingredients such as mineral oil, paraffin, white petrolatum, white wax and propylene carbonate.

Although its label suggests it is intended for treating moderate to severe eczema, the most important off-label use of Protopic is in the treatment of vitiligo.

Protopic is an immunosuppressant. Therefore, it should not be used by those with weakened immunity.

Although steroids are also immunomodulators, Protopic belongs to a different drug group. Unlike steroid creams, Protopic does not cause thinning skin. However, it is also not recommended for long-term use.

Protopic should only be used for a short while to reduce the incidence and severity of its side effects. Where it must be used for a long while, it should only be used in bursts with breaks in between the short periods during which it is applied to the skin.

Although Protopic carries a black box warning mandated by the FDA (in 2006) about its potential to increase the risk of skin cancer, reports of cancer with Protopic use has been very rare.

The animal testing study that informed the FDA decision was only done with large doses of drugs in the same class of tacrolimus.

In fact, the American Academy of Dermatology disagrees that the available evidence supports that conclusion and in other countries, Protopic is not associated with cancer risks.

Protopic should be withdrawn if no positive results are seen after 6 weeks of treatment. Although it is especially recommended for use in children, it should not be used on children younger than 2 years.

Besides those with a weakened immune system, other people who should not use Protopic are those with skin infections, people with the rare skin disorder called Netherton’s syndrome as well as pregnant and lactating women.

How to Use Protopic

Protopic is usually used to treat vitiligo patches on the face. As such it should be applied carefully to avoid contact with the eyes and mucosal surfaces.

First, wash your hands before applying Protopic. Then apply a thin layer of the ointment twice daily.

Avoid bathing or showering soon after applying the ointment or it will be washed off. However, wash off the ointment from your hands soon after application. Remove with soap and water.

You may apply a moisturizer and sunscreen (only when your physician instructs so) over the Protopic to protect your skin from drying and sun damage.

It is recommended that you limit exposure to sunlight and avoid tanning beds and ultraviolet lamps during the time you are using Protopic. Sources of ultraviolet radiation should be avoided even you are not wearing Protopic as long as you are still treating your vitiligo with the ointment.

Therefore, Protopic should not be combined with PUVA, narrow band UVB and any other light therapy used to treat vitiligo.

You do cover the treated areas of your skin with tight clothes or bandages or wraps. Rather, wear loose clothes when going outdoors.

What is Tacrolimus?

Tacrolimus is an immunosuppressant drug. By chemical structure, it is a macrolide. When classified by mechanism of action, it belongs to the pharmacological class of calcineurin inhibitors.

Tacrolimus is one of the first sets of macrolide immunosuppressants to be discovered.

It was extracted from a broth of fermented Japanese soil in 1984. The bacterium that secretes this macrolide is Streptomyces tsukubaensis. The name tacrolimus is taken from Tsukuba Macrolide Immunosuppressant.

As an immunosuppressant, tacrolimus is used to improve the success rate of an organ transplant by reducing patients’ immune systems and, therefore, the risk of organ rejection. It was first approved by the FDA in 1994 for liver transplants but it has since been approved for the transplantation of other organs including kidney, heart, bone marrow, cornea, lung, and skin.

In the US, both the oral and topical forms of tacrolimus are sold by Astellas Pharma under the trade names Prograf (used twice daily), Advagraf (used once daily) and Protopic.

The first 2 forms are capsules with Advagraf being the sustained release form of Prograf while Protopic is an ointment.

How Tacrolimus Works

One of the major ways by which the body mounts an autoimmune attack is through the signaling of T cells to release cytokines.

It starts with the activation of T cell receptors. This leads to inflow of calcium and the activation of a compound known as calcineurin. It is calcineurin that then activates nuclear factors and prompts the expression of genes that code for interleukins (IL-2, IL-3, IL-4, and IL-5) and tissue necrosis factor (TNF alpha).

Tacrolimus blocks calcineurin and prevents the cascade reaction that produces these cytokines.

This is why tacrolimus is called a calcineurin inhibitor. This action prevents the release of cytotoxic factors that can cause local inflammation on the skin and even destroy some skin cells.

While this action of tacrolimus prevents the rejection of donor organ, it also has the fortunate effect of protecting skin cells such as melanocytes. Therefore, tacrolimus is effective for blocking the autoimmune destruction of melanocytes.

In the treatment of eczema, the required effect of tacrolimus is the inhibition of inflammatory cytokines. However, in vitiligo, it is the inhibition of immune cells and factors that may cause local destruction of skin cells that is needed.

Topical tacrolimus has far fewer side effects than oral tacrolimus. This is because topical preparations mostly produce local effects on the skin and also because tacrolimus is not extensively absorbed through the skin.

Is Protopic Effective?

Protopic is a very effective alternative to topical corticosteroids especially for treating vitiligo in children and in visible areas such as the face. Protopic is commonly recommended for treating segmental vitiligo (rapidly spreading but localized vitiligo).

Both Protopic and topical steroids have anti-inflammatory and immunomodulatory properties but Protopic produces far fewer side effects on the skin.

Protopic (tacrolimus) and other topical drugs in its class such as pimecrolimus are increasingly replacing topical steroids even in the treatment of adult vitiligo. More studies are establishing their efficacy for treating this skin pigmentation disorder even though vitiligo still remains an off-label use of Protopic.

However, Protopic does not work for everyone.

While some vitiligo patients report excellent results from using this topical product, others do not see any improvement. It is more likely that Protopic will be effective for patients whose vitiligo breakouts are caused by the autoimmune destruction of their melanocytes.

The autoimmune theory is only one proposed cause of vitiligo. Other proposed theories include intrinsic defects in melanocytes, increased oxidative stress on the skin, nerve damage, toxic chemicals, nutritional deficiencies and genetic predisposition.

Therefore, Protopic can only be effective for the subset of patients whose hypopigmentation is caused by the autoimmune factors.

It is fairly easy to determine who such patients could be. They are the ones who also have other autoimmune diseases such as alopecia areata, diabetes mellitus, thyroid dysfunction etc. Vitiligo patients with autoimmune disorders usually have melanocyte-specific antibodies and increased blood levels of activated T cells.

If after 6 weeks of using Protopic, there is no significant improvement, it should be assumed that autoimmune destruction is not the cause of vitiligo, Protopic should be stopped and other treatments sought.