FYI on Recent Drug Trials
To date, there is no known cure for chronic fatigue syndrome, but medications to treat the illness are being studied, with varying results. Sometimes existing medications are tested for effectiveness in treating the symptoms of CFS. Here are some highlights from recent drug trials related to CFS.
Treatment with modafinil yields mixed results
A London study published last fall in the Journal of Psychopharmacology explored the effects of modafinil (Provigil)—a selective wakefulness-promoting agent—to determine its effects on cognition and fatigue in patients with CFS.
Fourteen patients classified as having CFS, but without concurrent major depression, significant sleepiness or use of psychoactive medication, completed the double-blind, placebo-controlled, crossover study. The treatment periods were 20 days each at 200mg and 400mg per day, with “wash out” periods of two weeks in between the two dosage levels.
In a test of sustained attention, treatment with 200mg of modafinil improved performance, but 400mg increased the number of mistakes. In a test of spatial planning, the 400mg dose reduced the initial thinking time for the hardest part of the test. But in a test of mental flexibility and motor speed, patients performed worse while on the modafinil than the placebo.
The authors of the study conclude that “chronic treatment with modafinil may not be beneficial in patients with chronic fatigue syndrome.”
Ritalin study shows modest results
In February a report was published in the American Journal of Medicine describing promising results from a pilot treatment study of the effects of methylphenidate (Ritalin) on 60 CFS patients.
Using a double-blind, randomized, placebo-controlled process, researchers found that controlled doses of the drug were statistically better than the placebo at relieving fatigue and concentration disturbances in a portion of the CFS patients studied.
Participants in the study were randomly assigned to four weeks of treatment with 10mg per day of methylphenidate, followed by four weeks of a placebo, or vice versa. During the course of the trial, fatigue scores fell significantly for 17 percent of participants during methylphenidate intake in comparison with both the placebo and the baseline. Twenty-two percent experienced improved concentration.
Further studies are needed to investigate the long-term effects of this treatment.
Note: Modafinil (Provigal) and methylphenidate (Ritalin) are both classified as stimulants, but their pharmacological profiles are different. In addition, each of the previously-mentioned studies measured very specific and different responses—perhaps leading to the diverse conclusions as to the benefits of the drugs.
Antidepressants show long-term benefits for CFS symptoms
Results were recently published from the longest study to date of the benefits of antidepressant medication in the recovery of CFS patients. The study, conducted by Marie A. Thomas and Andrew P. Smith of the Center for Occupational and Health Psychology at Cardiff University in the United Kingdom, included 275 patients who fulfilled the international case definition for CFS.
Forty-nine of these patients had been prescribed antidepressant medications such as tricyclic drugs or selective serotonin reuptake inhibitors (SSRIs). The others had not. As part of the investigation, all participants completed measures assessing illness history, global ratings of well-being, sleep, activity levels and psychopathology at various intervals from outset to 6 months, 18 months and a three-year follow-up.
The results, published in Human Psychopharmacology: Clinical and Experimental (18 September, 2006), suggest that CFS patients taking antidepressant medication recover from the effects of the illness at an increased rate over time compared to the untreated patient sample. Those taking the antidepressants—particularly the SSRIs—showed significantly lower total symptom scores. These improvements included a reduction in the levels of fatigue recorded by patients, as well as higher sleep quality. What’s more, the positive effects of antidepressant therapy remained viable at the three-year follow-up point.
Note: Similar findings haven’t been demonstrated in previous studies of antidepressant therapy for patients with CFS, possibly due to the shorter time periods examined in the earlier research. The researchers recommend additional investigation to corroborate their results.