For more severe forms of psoriasis, doctors sometimes prescribe medicines that are taken internally:
- Methotrexate--This treatment, which can be taken by pill or
injection, slows cell production by suppressing the immune system. Patients
taking methotrexate must be closely monitored because it can cause liver
damage and/or decrease the production of oxygen-carrying red blood cells,
infection-fighting white blood cells, and clot-enhancing platelets.
As a precaution, doctors do not prescribe the drug for people with long-term
liver disease or anemia. Methotrexate should not be used by pregnant
women, by women who are planning to get pregnant, or by their male partners.
- Cyclosporine--Taken orally, cyclosporine (Neoral)
acts by suppressing the immune system in a way that slows the rapid
turnover of skin cells. It may provide quick relief of symptoms, but
it is usually effective only during the course of treatment. The best
candidates for this therapy are those with severe psoriasis who have
not responded to or cannot tolerate other systemic therapies. Cyclosporine
may impair kidney function or cause high blood pressure (hypertension),
so patients must be carefully monitored by a doctor. Also, cyclosporine
is not recommended for patients who have a weak immune system, those
who have had substantial exposure to UVB or PUVA in the past, or those
who are pregnant or breast-feeding.
- Hydroxyurea (Hydrea®)--Compared with
methotrexate and cyclosporine, hydroxyurea is less toxic but also less
effective. It is sometimes combined with PUVA or UVB. Possible side
effects include anemia and a decrease in white blood cells and platelets.
Like methotrexate and cyclosporine, hydroxyurea must be avoided by pregnant
women or those who are planning to become pregnant.
- Retinoids--A retinoid, such as acitretin (Soriatane),
is a compound with vitamin A-like properties that may be prescribed
for severe cases of psoriasis that do not respond to other therapies.
Because this treatment also may cause birth defects, women must protect
themselves from pregnancy beginning 1 month before through 3 years after
treatment. Most patients experience a recurrence of psoriasis after
acitretin is discontinued.
- Antibiotics--Although not indicated in routine treatment, antibiotics may be employed when an infection, such as Streptococcus, triggers the outbreak of psoriasis, as in certain cases of guttate psoriasis.
