Small, "naturalistic" study shows treatment with desvenlafaxine produces high rates of symptom improvement and remission with low rates of adverse events in patients with major depressive disorder.
Desvenlafaxine (brand name: Pristiq) was tested in clinical trials and was approved by the US Food and Drug Administration in 2008 for the treatment of major depressive disorders in adults. Now, a team of 10 physicians from Argentina, Chile, Colombia, and Mexico has tested the drug in a “naturalistic,” real-world setting in clinical practice.
Although the researchers will continue to monitor the patients for another year, the results so far indicate strong effectiveness even outside of pristine lab conditions, including among people taking other medications, the researchers reported on Sunday, May 4, at the 2014 annual meeting of the American Psychiatric Association in New York City, NY.
“Patients who had a history of more depressive episodes and more treatment recovered less,” said Daniel Mosca, MD, a psychiatrist at the Alvear Emergency Psychiatric Hospital in Buenos Aires.
The physicians recruited the 90 volunteer participants from among patients that they had determined were appropriate candidates to start treatment with the drug.
The trial began in November 2013 with patients receiving once-daily desvenlafaxine 50 mg, for a period of up to 6 months. After two months, 15 patients who showed low response levels based on HAM-D and MADRS scores had their dosages increased to once-daily desvenlafaxine 100 mg. After two more months, if they were still not responsive, another antidepressant was added: 6% were given buproprion (Wellbutrin and other brand names), 5% each mirtazapine (Remeron) or lamotrigine (Lamictal), and 3% received aripiprazole (Abilify).
At the end of six months, 73% of patients showed at least a 50% level of improvement in the standard assessments of anxiety systems, including 54% who were in complete remission. Ten percent had dropped out of the trial: four people because of lack of responsiveness, three due to side effects, and two who lost contact.
The scientists reported several adverse side effects, the most common of which (nausea, experienced by 18 people) disappeared within six days. Other adverse effects included decreased libido (4 people), insomnia (4 people), delayed ejaculation (3 people), and constipation (1 person).
However, the National Institutes of Health lists a wide range of potential side effects, most seriously an increased risk of suicide among children, teenagers, and young adults. Some of the 40 other possible side effects cited by the NIH are rash, vomiting, drowsiness, difficulty breathing, chest pain, dizziness, shaking, and blurred vision.
Although the main part of this trial ended one month ago, the study is not completely over. The patients who exhibited complete remission will continue on whatever their ending dosage was, and their doctors will follow up with them at 12 months and again at 18 months to analyze their condition at those points.
Mosca said that the results were not surprising, since they echo the clinical trials and what he has observed informally in his work. Nevertheless, he said there was value in conducting this research. “In the clinical trials, you have to select the same kind of people,” he said. But in this research, “we really had a random selection of whoever was willing.”