There is little to no information on the impact on pregnancy of therapies approved to manage fibromyalgia nerve pain, a study has found.
Because of this lack of data, the decision on whether to continue these therapies during pregnancy should be carefully considered, researchers suggest.
The review study, “Managing fibromyalgia syndrome in pregnancy no bridges between USA and EU,” was published in the journal Archives of Women’s Mental Health.
Fibromyalgia is characterized by generalized chronic pain, so it is mainly recognized as a pain disorder, at least in the rheumatology and pain communities. In other clinical fields, fibromyalgia has been perceived as a symptomatic or psychosomatic disorder, meaning a physical disease caused by mental factors.
Previous studies have reported that various psychiatric conditions, including mood and anxiety disorders, can coexist with fibromyalgia. Specifically, reports have noted that 20-80% of fibromyalgia patients experience major depression, while many patients may also have persistent depressive disorder (dysthymia) and generalized anxiety disorder.
Although there is no clear evidence that fibromyalgia has a negative impact on pregnancy outcomes, some studies have suggested that the disease can increase the risk of delivery complications and health problems for the newborn. This underscores the need for better understanding on the effects fibromyalgia treatments can have on pregnancy.
Italian researchers reviewed publicly available information on approved therapies for fibromyalgia, including Cymbalta (duloxetine), Lyrica (pregabalin), and Savella (milnacipran), as well as for nonpharmacological interventions, such as cognitive behavioral therapy.
Data collected from case reports and controlled trials revealed that treatment with Cymbalta is not associated with congenital malformations of the fetus. However, as it was reported with Effexor (venlafaxine), it may induce neonatal symptoms attributable to the onset of prenatal antidepressant exposure syndrome.
Cymbalta’s use has also been linked to some complications during pregnancy such as gestational hypertension and preeclampsia.
“Obviously, women should be informed about the teratogenic [potentially dangerous to the fetus] risks associated with [Cymbalta],” the researchers wrote.
Regarding Savella use, there is no available information about its possible effects on pregnant women or on the unborn child. This is currently being evaluated in the ongoing Savella Pregnancy Registry (NCT01026077), which is still recruiting participants.
This U.S.-based study was designed to monitor pregnant women exposed to Savella, and estimate the prevalence of major congenital anomalies as well as pregnancy complications.
“Waiting for the first reproductive safety data, [Savella] use should be avoided in pregnant women with fibromyalgia syndrome,” the authors said.
Studies on the use of Lyrica have not provided very positive results. They have found that treatment with this agent is associated with an increased risk of major birth defects, including central nervous system and heart defects, especially if taken during the first trimester of a pregnancy. But these results are controversial due to the limited number of women included in the studies.
“Available data, albeit inconclusive, seem to suggest that the drug is not devoid of structural terogenicity potential,” the researchers wrote. “The over-causal handling, off-label use of [Lyrica] in pregnancy must be strongly stigmatized and condemned.”
In the literature review, the team found almost no information on the impact on pregnancy of nonpharmacological treatments for fibromyalgia.
However, a clinical trial conducted in women who were not pregnant demonstrated that cognitive behavioral therapy could effectively reduce symptoms and disability of fibromyalgia when administered both in short- and long-term regimens.
These findings suggest that all women requiring the use of these medications due to severe symptom worsening during pregnancy should be carefully monitored. Decisions on treatment should be carefully made by weighing the benefits and risks.
“The future direction of research in the field should be focused to definitively establish whether or not [Cymbalta], [Lyrica], and [Savella] work effectively in fibromyalgia syndrome,” the researchers said, adding that “non-pharmacological interventions and, especially, cognitive behavioral therapy should be proved to be effective even during pregnancy.”