Last updated: May 20, 2009
"The good news is that psoriasis is manageable, manageable now to the point that for the majority of patients we can completely clear the skin of all skin lesions and do so fairly safely. Just a few years ago, we didn't have such great options," says Steven Feldman, MD, PhD, professor of dermatology at the Wake Forest University School of Medicine in Winston-Salem, N.C. "Treatments are now more effective, safer and easier to use than ever."
One of the main advantages of oral medications is how long the drugs have been around. "Most doctors are going to start you off with the medication that has the fewest side effects and the least chance of causing harm,” says Kathy Kavlick, RN, community outreach nurse for the Murdough Family Center for Psoriasis in Cleveland. In comparison to some of the newer psoriasis drugs on the market, Kavlick says, "these systemics have been around a lot longer, so we know a lot more about their long-term effects and what to watch for."
If your psoriasis causes significant discomfort or pain or covers a sizable part of your body, your dermatologist is likely to discuss the possibility of using a systemic. Some insurance companies also require psoriasis patients to try an oral medication before starting a biologic, since biologics are far more expensive. The primary oral medications prescribed for psoriasis are methotrexate, cyclosporine, and acitretin.
Heres what you should know about the different systemic medications:
What it is: Methotrexate belongs to a class of drugs known as antimetabolites, and it works by interfering with the overproduction of skin cells that causes psoriatic plaques to develop. Methotrexate is usually taken once a week in a single dose of up to 30 mg, although it is sometimes broken up into three smaller doses spread out over a 24-hour period.
Efficacy: Studies have shown that methotrexate is effective in 70% to 80% of psoriasis patients. In a 2003 study of oral medications published in the New England Journal of Medicine, 60% of the patients who received methotrexate experienced partial remission; of those patients, 65% saw near-complete remission. Patients usually start to see results after two to three months.
Side effects: The most common side effect is nausea, which is usually alleviated by supplementing the drug with folic acid. Other side effects are more serious. Liver damage is a primary concern with methotrexate, especially for people who drink alcohol or who are diabetic or obese. (The risk of liver damage is high enough that, after taking the drug for a year or more, patients often require a liver biopsy to test for toxins in the organ.) Methotrexate can also cause birth defects and cannot be used during pregnancy.
What it is: Cyclosporine is an immunosuppressant drug that fights psoriasis by suppressing the faulty immune cells that signal skin cells to grow too quickly. It is usually taken once a day as a capsule or in liquid form.
Efficacy: In more than a dozen studies, cyclosporine has been shown to produce significant improvement in psoriasis in up to 90% of the patients who take it. One of its main benefits is that it works quickly, usually in as little as two weeks.
In the New England Journal of Medicine study mentioned above, cyclosporine slightly outperformed methotrexate. More than 70% of the patients who received cyclosporine experienced a partial remission, although less than half of them experienced near-complete remission. In a more recent study comparing three-month treatments of cyclosporine and methotrexate, patients saw their psoriasis symptoms decrease by 72% and 58%, respectively.
Side effects: Cyclosporine reduces the flow of blood through the kidneys, which impairs their function and can cause serious damage over time. Cyclosporine can also cause high blood pressure, although limiting the course of treatment to a few months appears to mitigate this side effect. Other relatively minor side effects include nausea, joint pain, headache, and fatigue. (Cyclosporine has also been shown to raise the risk of non-melanoma skin cancer six-fold, but only in patients who have previously undergone a type of phototherapy known as PUVA.)
What it is: Acitretin is a retinoid, a type of synthetic vitamin A. Usually known by its brand name, Soriatane, acitretin is taken as a once-a-day pill and is the only oral systemic not available as a generic. It is often combined with phototherapy.
Efficacy: What little research exists on the use of Soriatane alone has shown that it can produce mild to moderate clearance. Soriatane seems to be most effective and useful as an addition to phototherapy, however. A pair of studies that compared the combination of UVB phototherapy and Soriatane with the phototherapy alone found that adding Soriatane more than doubled the number of patients who experienced improvement or clearing of their psoriasis.
Side effects: Most of the side effects associated with Soriatane are minor. They include lip inflammation, dry mouth, skin thinning and fragility, joint and muscle pain, and hair loss (alopecia). Potentially more serious side effects include liver damage, skeletal abnormalities, and an elevation of cholesterol and triglycerides. Soriatane is also known to cause birth defects, so it is not an option for women who may become pregnant.
How are they used?
Each systemic medication has its own advantages and potential complications. Although patients sometimes stay on one medication for months (or even years), dermatologists have found that they may be able to maximize the advantages and minimize the complications of these drugs by prescribing them in sequence.
Methotrexate and cyclosporine clear psoriasis more quickly than Soriatane, for instance, but are less appropriate for long-term “maintenance” therapy due to the potential for liver and kidney damage. Cyclosporine, for instance, cannot be taken continuously for more than a year. Some dermatologists will therefore prescribe an initial dose of methotrexate or cyclosporine, add Soriatane after a month or two, and then gradually taper off the more powerful systemic.
In other cases, dermatologists will simply rotate through the various systemic medications to lessen the risk of side effects. Systemic drugs are also frequently prescribed in combination. This appears to enhance their efficacy, and it also allows each drug to be given in lower doses, which minimizes the potential for any one long-term side effect.