Publish date: September 10, 2019

The last decade has brought increasing awareness of the need to effectively screen for postpartum depression, with a majority of states across the country now having some sort of formal program by which women are screened for mood disorder during the postnatal period, typically with scales such as the Edinburgh Postnatal Depression Scale (EPDS).In addition to effective screening is a pressing need for effective referral networks of clinicians who have both the expertise and time to manage the 10%-15% of women who have been identified and who suffer from postpartum psychiatric disorders – both postpartum mood and anxiety disorders. Several studies have suggested that only a small percentage of postpartum women who score with clinically significant level of depressive symptoms actually get to a clinician or, if they do get to a clinician, receive adequate treatment restoring their emotional well-being (J Clin Psychiatry. 2016 Sep;77[9]:1189-200).Zulresso (brexanolone), a novel new antidepressant medication which recently received Food and Drug Administration approval for the treatment of postpartum depression, is a first-in-class molecule to get such approval. Zulresso is a neurosteroid, an analogue of allopregnanolone and a GABAA receptor–positive allosteric modulator, a primary inhibitory neurotransmitter in the brain.

Zulresso, an IV infusion, was developed by its manufacturer Sage Therapeutics specifically for moderate to severe postpartum depression. There is every reason to believe that, as a class, this group of neurosteroid molecules are effective in treating depression in other populations aside from women with postpartum depression and hence may not be specific to the postpartum period. For example, recent presentations of preliminary data suggest other neurosteroids such as zuranolone (an oral medication also developed by Sage Therapeutics) is effective for both men and women who have major depression in addition to women suffering from postpartum depression.

Zulresso is approved through a Risk Evaluation and Mitigation Strategy–restricted program and, per that protocol, needs to be administered by a health care provider in a recognized health care setting intravenously over 2.5 days (60 hours). Because of concerns regarding increased sedation, continuous pulse oximetry is required, and this is outlined in a boxed warning in the prescribing information. Zulresso has been classified by the Drug Enforcement Administration (DEA) as a Schedule IV injection and is subject to the prescribing regulations for a controlled substance.

Since Zulresso’s approval, my colleagues and I at the Center for Women’s Mental Health have received numerous queries from patients and colleagues about our clinical impression of this new molecule with a different mechanism of action – a welcome addition to the antidepressant pharmacopeia. The question posed to us essentially is: Where does brexanolone fit into our algorithm for treating women who suffer from postpartum depression? And frequently, the follow-up query is: Because subjects in the clinical trials for this medication included women who had onset of depression either late in pregnancy or during the postpartum period, how specific is brexanolone with respect to being a targeted therapy for postpartum depression, compared with depression encountered in other clinical settings.

What clearly can be stated is that Zulresso has a rapid onset of action and was demonstrated across clinical trials to have sustained benefit up to 30 days after IV administration. The question is whether patients have sustained benefit after 30 days or if this is a medicine to be considered as a “bridge” to other treatment. Data answering that critical clinical question are unavailable at this time. From a clinical standpoint, do patients receive this treatment and get sent home on antidepressants, as we would for patients who receive ECT, often discharging them with prophylactic antidepressants to sustain the benefit of the treatment? Or do patients receive this new medicine with the clinician providing close follow-up, assuming a wait-and-see approach? Because data informing the answer to that question are not available, this decision will be made empirically, frequently factoring in the patient’s past clinical history where presumably more liberal use of antidepressant immediately after the administration of Zulresso will be pursued in those with histories of highly recurrent major depression.

So where might this new medicine fit into the treatment of postpartum depression of moderate severity, or modest to moderate severity? It should be kept in mind that for patients with mild to moderate postpartum depression, there are data supporting the efficacy of cognitive-behavioral therapy (CBT). CBT frequently is pursued with concurrent mobilization of substantial social support with good outcomes. In patients with more severe postpartum depression, there are data supporting the use of antidepressants, and in these patients as well, use of established support from the ever-growing network of community-based support groups and services can be particularly helpful. It is unlikely that Zulresso will be a first-line medication for the treatment of postpartum depression, but it may be particularly appropriate for patients with severe illness who have not responded to other interventions.

Other practical considerations regarding use of Zulresso include the requirement that the medicine be administered in hospitals that have established clinical infrastructure to accommodate this particular population of patients and where pharmacists and other relevant parties in hospitals have accepted the medicine into its drug formulary. While coverage by various insurance policies may vary, the cost of this new medication is substantial, between $24,000 and $34,000 per treatment, according to reports.

Where Zulresso fits into the pharmacopeia for treating postpartum depression may fall well beyond the issues of efficacy. Given all of the attention to this first-in-class medicine, Zulresso has reinforced the growing interest in the substantial prevalence and the morbidity associated with postpartum depression. It is hard to imagine Zulresso being used in cases of more mild to moderate depression, in which there is nonemergent opportunity to pursue options that do not require a new mom to absent herself from homelife with a newborn. However, in picking cases of severe new onset or recurrence of depression in postpartum women, the rapid onset of benefit that was noted within days could be an extraordinary relief and be the beginning of a road to wellness for some women.

Ultimately, the collaboration of patients with their doctors, the realities of cost, and the acceptability of use in various clinical settings will determine how Zulresso is incorporated into seeking treatment to mitigate the suffering associated with postpartum depression. We at the Center for Women’s Mental Health are interested in user experience with respect to this medicine and welcome comments from both patients and their doctors at admin@womensmentalhealth.org.

Dr. Cohen is the director of the Ammon-Pinizzotto Center for Women’s Mental Health at Massachusetts General Hospital in Boston, which provides information resources and conducts clinical care and research in reproductive mental health. This center was an investigator site for one of the studies supported by Sage Therapeutics, the manufacturer of Zulresso. Dr. Cohen is also the Edmund and Carroll Carpenter professor of psychiatry at Harvard Medical School, also in Boston. He has been a consultant to manufacturers of psychiatric medications. Email Dr. Cohen at obnews@mdedge.com