The Food and Drug Administration approval of zuranolone for postpartum depression in August 2023 has raised many important questions (and opinions) about its future use in clinical practice.
At the UNC-Chapel Hill Center for Women’s Mood Disorders, we treat women and pregnant people throughout hormonal transitions, including pregnancy and the postpartum, and have been part of development, research, and now delivery of both brexanolone and zuranolone. While we are excited about new tools in the arsenal for alleviating maternal mental health, we also want to be clear that our work is far from complete and continued efforts to care for pregnant people and their families are imperative.
courtesy UNC-Chapel Hill
Dr. Julia Riddle
What is zuranolone?
Zuranolone (brand name Zurzuvae) is an oral medication developed by Sage Therapeutics and Biogen. It is a positive allosteric modulator of the GABAA receptor, the brain’s major inhibitory system. As a positive allosteric modulator, it increases the sensitivity of the GABAA receptor to GABA.
Zuranolone is very similar to brexanolone, a synthetic form of allopregnanolone, a neurosteroid byproduct of progesterone (see below). However, zuranolone is not an oral form of brexanolone – it was slightly modified to ensure good oral stability and bioavailability. It is metabolized by the hepatic enzyme CYP3A4 and has a half-life of 16-23 hours. Zurzuvae is currently produced in capsule form.
What does zuranolone treat?
Zuranolone is the first FDA-approved oral drug for postpartum depression (PPD). It follows brexanolone, an intravenous drug, which was the first FDA-approved medication for PPD. Though these are the first medications with specific approval for PDD, many other treatment options are currently available including therapy, SSRIs, serotonin norepinephrine reuptake inhibitors (SNRIs), and other treatments used in major depression.
How does zuranolone work?
courtesy UNC-Chapel Hill
Dr. Elizabeth Richardson
Zuranolone is a neuroactive steroid, which means that it is a steroid that goes into and acts on the brain. Zuranolone binds to different GABA receptor subunits from those bound by other positive modulators, such as benzodiazepines (for example, lorazepam). As a synthetic form of allopregnanolone, a metabolite of progesterone which rises dramatically in pregnancy then drops during labor and delivery, zuranolone was originally thought to mitigate the response to this drop in patients that are vulnerable to it during the postpartum. An alternative proposed mechanism is that the increased GABAergic, inhibitory signaling with zuranolone may act directly to decrease depression irrespective of the exact mechanism by which the depression occurred.
How was it studied?
Zuranolone was studied in women with severe postpartum depression and had to meet criteria for major depressive disorder (MDD) no earlier than the third trimester of pregnancy (about 28 weeks’ gestation) and no later than 4 weeks post partum. Patients were excluded from these studies if they had a history of bipolar disorder, psychotic disorders, attempted suicide, or if they were at risk for suicide.
The two phase 3 clinical trials that led to FDA approval are ROBIN and SKYLARK. These studies measured the efficacy and safety of zuranolone at 30 mg and 50 mg, respectively, and met their end points of rapid improvement in depressive and anxiety symptoms in postpartum depression.
When will we be able to start using it?
It is anticipated that zuranolone will become commercially available in early 2024.
Who can prescribe it?
courtesy UNC-Chapel Hill
Dr. Margo Nathan
Those with medical licenses. Most people will likely receive treatment from their obstetric, family medicine, or psychiatric clinicians.
How much will it cost?
The manufacturers have not released this information as of August 2023.
What sort of doses and duration is recommended?
The current FDA recommended dose is 50 mg for 14 days, taken once per evening with a fatty meal. The dose can be reduced to 40 mg if there are central nervous system (CNS) depressant effects, and to 30 mg if the patient has severe hepatic or moderate-severe renal impairment. There are currently no studies on longer courses of treatment.
What happens if the patient relapses after a 14-day trial?
While there is no clear guidance, an open-label trial (The SHORELINE Study) demonstrated that a repeated 14-day administration can restore clinical response.
What are the side effects?
courtesy UNC-Chapel Hill
Dr. David Rubinow
Common side effects include drowsiness, dizziness, lower energy, diarrhea, and symptoms similar to the common cold. Zuranolone can act like a CNS depressant and can lead to sedation and somnolence.
Are there any boxed warnings?
Because of the CNS depressant effects, zuranolone was given a boxed warning that patients should not drive or operate heavy machinery within 12 hours of taking the medication as it may lead to impairment. Similar to other antidepressants, there is also a warning that zuranolone may increase risk for suicidal thoughts in patients under 24 years old.
Can it be used with other medications?
Yes. In the original trials, women were allowed to remain on medications treating their depressive symptoms (such as SSRIs and SNRIs). According to the FDA, zuranolone can be used alone or with other antidepressants.
Are there any medicines to avoid?
We recommend caution with other medications which may increase sedation, such as benzodiazepines.
Can it be used with birth control?
Yes. In fact, because the outcomes on a fetus are not yet studied, it is recommended that patients be on concurrent birth control during treatment and for a week after cessation. This does not mean that zuranolone is known to cause issues with fetal development, but rather that we do not know at this time.
Can it be used in pregnancy?
As above, the outcomes on fetal development are not known at this time, nor are the effects of zuranolone on labor and delivery. More research will need to be done to understand if there is risk with taking zuranolone during pregnancy. It should be noted that allopregnanolone levels ordinarily reach quite high levels during pregnancy.