What Is a Citrate-Free Biologic?

From topical treatments to light therapy to oral or injected medications, there are many approaches to treatment for psoriatic arthritis.¹ One such treatment approach is the use of biologics. Biologics are drugs that alter the immune system by blocking activity that leads to inflammation.^1,2 Biologics are given by injection and are typically used for patients who have not had a good response to other traditional therapies.¹

Biologics: The good and the bad

Because biologics work by altering the effects of the immune system, treatment with a biologic can be very effective in treating autoimmune diseases. These medications effectively reduce inflammation, which can slow down or stop the progression of disease.² The use of biologics comes with some risks, however. They can inhibit the body’s ability to fight off infection, which can increase the risk of certain cancers or other conditions, such as tuberculosis and fungal infections.² Also, injection site reactions, such as redness, burning, or stinging, are quite common with the use of injectable biologics.^2,3 The amount of discomfort a patient experiences may affect his or her adherence to treatment, and therefore the overall effectiveness of the medication.³

What causes stinging and discomfort?

Pain at the injection site can be caused by several different factors. All biologic injectables include inactive ingredients such as citrate buffer, to help with the preservation of the medicine. Other factors such as the amount of medicine injected per dose and needle size can also contribute to pain and burning.⁴

What is citrate?

Citrate is a chemical buffer that is added to medications like biologics to help maintain the structure of the medicine. With protein-based medicines like biologics, the effectiveness of the treatment relies heavily on keeping the chemical structure balanced. Citrate does this.⁵

Is there a citrate-free option available?

One common biologic used to treat psoriatic arthritis and other inflammatory autoimmune diseases is Humira. Humira is a highly effective biologic treatment that recently released a citrate-free formula.^4,6 With this new version of Humira, citrate is not included, and a different buffer is used. In addition, the volume of liquid being injected is smaller, as are the needles. The dose and effectiveness, however, is the same.^6,7 Other brands of biologics are also currently working on the development of citrate-free formulas.⁷

How does a citrate-free formula compare with other injectable biologics?

Many patients report burning and stinging at the place of injection. However, studies have shown that patients using the citrate-free formula of Humira experience less pain than with the original formula that contains citrate.^4,6