Dermatologists emphasize treatment should be tailored to meet
individual patients' needs
SCHAUMBURG, Ill., June 4 /PRNewswire-USNewswire/ -- Based on an extensive review of scientific literature on psoriasis and the opinion of recognized psoriasis experts, the American Academy of Dermatology (Academy) has released new guidelines of care for the management and treatment of psoriasis with traditional systemic therapies. Recommendations, efficacy and safety for the use of the three U.S. Food & Drug Administration (FDA) approved and most commonly used traditional systemic agents - methotrexate, cyclosporine and acitretin - were outlined.
Published online in the Journal of the American Academy of Dermatology, this is the Academy's fourth of six sections of the guidelines of care for psoriasis, with three previously published sections focusing on general recommendations for the treatment of psoriasis and psoriatic arthritis, as well as the use of biologics and topical therapies.
"While in recent years biologics have changed the treatment of psoriasis, traditional systemic therapies - which are easily administered orally and less expensive than biologics - continue to play an important role in treating psoriasis," said dermatologist David M. Pariser, MD, FAAD, president of the Academy. "The Academy's new evidence-based guidelines are intended as a guide for physicians so the best treatment can be determined for each individual patient. The guideline also discussed any potential side effects or risk factors that need to be evaluated prior to treatment."
Psoriasis is a chronic skin condition, which usually begins before age 35 and is characterized by thick, red, scaly patches that itch and bleed. Although it is a genetic disease, it is not completely understood how it is inherited. However, there are at least eight chromosomes to date that researchers have identified as being linked to the genetic transmission of the disease.
Although a prerequisite to starting a systemic therapy traditionally has been whether a patient is affected by psoriasis over a minimum body surface area of about 10 percent, a subset of patients with limited psoriasis have debilitating symptoms on their palms, soles or scalp that can significantly impact their quality of life - making systemic treatments an appropriate option for them.
As the most commonly prescribed traditional systemic therapy for psoriasis, methotrexate can be very effective with even the most severe cases of psoriasis. Methotrexate works by competitively inhibiting the enzyme dihydrofolate reductase, which decreases the production of folic acid thus blocking DNA synthesis and cell division.
Efficacy & Dosage
In the only placebo-controlled trial of methotrexate for psoriasis, 36 percent of patients treated with a low weekly dosage of 7.5 mg of methotrexate - which was increased as needed up to 25 mg per week - achieved a 75 percent or greater improvement in their Psoriasis Area and Severity Index (PASI) score after 16 weeks. In general, methotrexate is administered as a single weekly oral dose that can be increased gradually until an optimal response is achieved. Although there are no established maximum or minimum dosages of methotrexate, weekly dosages usually range from 7.5 mg to 25 mg.
"Some patients can be gradually tapered off treatment and restarted when the psoriasis recurs, and it is important for physicians to minimize the total cumulative dose of methotrexate while maintaining adequate control of psoriasis and the patient's tolerance of the medication," said Dr. Pariser.
Toxicities & Contraindications
Because of the known organ toxicities of traditional systemic medications, proper patient selection and appropriate monitoring are crucial to minimize the toxicity of any therapy. For example, the most common and generally minor side effects of methotrexate that most often occur at the time it is administered include nausea, fatigue, inflammation of the mucous membranes of the mouth and anorexia. The most serious toxicities associated with methotrexate are white blood cell and platelet deficiency, liver damage and lung scarring.
Since methotrexate can cause birth defects or terminate a pregnancy, it is not prescribed to women attempting to conceive. In addition, methotrexate should not be prescribed to nursing mothers, those with chronic liver disease, alcoholics, or patients with immunodeficiency syndromes, among others.
Cyclosporine is one of the most effective treatments for psoriasis and induces immunosuppresion by inhibiting the first phase of T-cell activation. When the medication is used long-term (i.e., three to five years), a significant number of patients will develop some degree of glomerulosclerosis, scarring of the kidney's blood vessels. For this reason, Dr. Pariser noted that published guidelines in the United States limit the use of cyclosporine to one year.
Efficacy & Dosage
Numerous clinical trials have demonstrated the efficacy of cyclosporine used as a short-term treatment for psoriasis, with minimal toxicities in healthy patients. Specifically, studies show at 3 mg/kg and 5 mg/kg per day, 36 percent and 65 percent of patients, respectively, achieved a clear or almost clear result after eight weeks. In addition, after eight to 16 weeks, 50 to 70 percent of patients achieved a 75 percent or greater improvement in their PASI score. Cyclosporine is generally prescribed to adult, non-immunocompromised patients with severe psoriasis who have not responded to at least one systemic therapy or in patients who cannot tolerate other systemic medications.
Generally, dosing of cyclosporine is given as 2.5 mg/kg to 5.0 mg/kg a day in two divided doses, and physicians should make decreased dose adjustments by 0.5 mg/kg to 1.0 mg/kg when psoriasis is cleared or when high blood pressure or decreased kidney function test results are observed.
Toxicities & Contraindications
The most serious side effects associated with cyclosporine are kidney damage and high blood pressure, which is why it requires careful patient selection and subsequent monitoring to be used safely. A number of drug interactions can occur with this medication, and the FDA advises that it should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus.
"Studies also show that patients with psoriasis taking cyclosporine may be at increased risk of developing squamous cell carcinoma, particularly those with a history of more than 200 PUVA treatments," said Dr. Pariser. "Due to these known toxicities and contraindications, a careful assessment of a psoriasis patient's disease severity is critical when assessing the risk-benefit ratio of treatment with cyclosporine."
Acitretin is an oral retinoid, which is derived from vitamin A. Although the exact way retinoids work in the treatment of psoriasis is not completely understood, they are known to inhibit excessive cell growth and stimulate differentiation of the epidermis (outermost layer of the skin). Etretinate was the first retinoid introduced for the treatment of severe psoriasis and was replaced by acitretin, the active metabolite of etretinate, in 1988.
Efficacy & Dosage
Clinical studies suggest that when used alone, acitretin is the least effective of the traditional systemic therapies and is therefore often used in conjunction with ultraviolet (UV) light. The effectiveness of acitretin is dose dependent, with dosing ranging from 10 mg to 50 mg per day administered as a single dose.
"Typically, it takes three to six months for acitretin to achieve the desired response in most psoriasis patients," explained Dr. Pariser. "Appropriate dosing must take into account the balance among safety, tolerability and efficacy, as many patients may not be able to tolerate the higher dosages of acitretin needed for optimal efficacy."
Toxicities & Contraindications
Several potential adverse effects are associated with acitretin, such as alopecia, nausea and abdominal pain, and joint and muscle pain, to name a few. However, Dr. Pariser explained that these can generally be minimized by appropriate patient selection, careful dosing and monitoring. As is the case with methotrexate, acitretin's most serious side effect is its potential to cause birth defects. Therefore, its use is limited to male and female patients of non-childbearing potential. In addition, other increased risks include severely impaired liver or kidney function and chronic, abnormally elevated blood lipid values. For this reason, patients should be monitored with lipid profiles and liver enzymes once every two weeks after starting acitretin.
"These guidelines emphasize that the decision to prescribe methotrexate, cyclosporine, acitretin or any other traditional therapy must be individualized," said Dr. Pariser. "Under the right circumstances, systemic therapies can significantly improve even the more severe cases of psoriasis. But every patient needs to be carefully evaluated in terms of disease severity, quality of life, and general medical and psychological history. Dermatologists and patients must work together to continually review the response to treatment and potential risks."
To learn more about psoriasis, visit the PsoriasisNet section of www.skincarephysicians.com, a Web site developed by dermatologists that provides patients with up-to-date information on the treatment and management of disorders of the skin, hair and nails.
Headquartered in Schaumburg, Ill., the American Academy of Dermatology (Academy), founded in 1938, is the largest, most influential, and most representative of all dermatologic associations. With a membership of more than 16,000 physicians worldwide, the Academy is committed to: advancing the diagnosis and medical, surgical and cosmetic treatment of the skin, hair and nails; advocating high standards in clinical practice, education, and research in dermatology; and supporting and enhancing patient care for a lifetime of healthier skin, hair and nails. For more information, contact the Academy at 1-888-462-DERM (3376) or www.aad.org.
Editor's Note: A copy of the guidelines can be accessed through the Academy's Web site at http://www.aad.org/research/guidelines/index.html.
|SOURCE American Academy of Dermatology|
Copyright©2009 PR Newswire.
All rights reserved