Todays clinical pearl comes from Nicholas Goodwin, DNP PMHNP who recently collaborated with me on our two new psychiatric based courses:

Should Mirtazapine be used regularly for sleep aid?

When it comes to treating insomnia, finding a medication that provides quick relief can be a challenge!  Especially when the go-tos have already not worked or have not been tolerated well (i.e. Trazodone, hydroxyzine, melatonin etc.) 

There are also some obvious good reasons to try and avoid the potentially addictive or abuseable sleep aids like zolpidem or benzodiazepines.

Mirtazapine is an antidepressant that also can be very sedating which can make for a good sleep agent.  As to whether it should be regularly considered greatly depends on the clinical situation as we will discuss below.

Before treating sleep issues or insomnia, the cause of that insomnia should be assessed for.  In my practice I see insomnia usually as secondary to mood disorders. But other primary causes like sleep apnea, restless legs, and vasomotor symptoms should be screened and ruled out as well.  Sometimes the insomnia is primary and does not seem to have any originating issue.

For people with depression with insomnia, mirtazapine can be a nice choice as it is therapeutic at 15mg and very sedating at that dose too.  So, one can treat depression and insomnia with 1 medication.  However, with the side effect panel I would still closely screen this patient, as this still may not be first line.

Pros of Mirtazapine:

• Antidepressant effect at doses of 15mg +. Most guidelines put mirtazapine as 2^nd or 3^rd line for depression, but for the right client, 1^st line may be considered.
• Sedating effect at doses of 7.5+, but seem to remain sedating even at 45mg
• Powerful antidepressant augmenter (combination of venlafaxine and mirtazapine is coined “California rocket fuel”)
• Lower risk for sexual side effects, or even completely neutral for sexual side effects, compared to other ssri/snri’s. 
• Can function as an anti-nausea agent, so this is ideal as nausea is a common side effect which is a deterrent for people looking at medication management.
• Can treat akathisia and drug induced akathisia- akathisia is a potentially dangerous and a very uncomfortable movement disorder (not at higher doses).
• Potent appetite inducer for underweight clients, clients with anorexia, or clients experiencing appetite suppression from other medication

CONS of Mirtazapine

• Too sedating- unlike trazodone, mirtazapine seems to be as sedating at every dose and sometimes that is too much. I have had clients tell me they slept over 24 hours on it.  The sedation can lessen with time but sometimes after weeks, which many clients are not ok with.
• Appetite inducing: This is often the first thing clients tell me, “I don’t want a medication that causes weight gain”, as far as meds that cause weight gain, mirtazapine is close to the top.  Weight gain can further increase the risk of metabolic syndrome and diabetes.  Therefore, mirtazapine is probably only an appropriate first line for some clients, and not usually for any non-mood disorder treatment (insomnia, nausea, akathisia) either due to this risk.
• Potent activator: Due to its potent antidepressant effect, especially in combination with another antidepressant, activation can be a risk as well. I used it in a client with severe depression with venlafaxine. She felt great and stopped needing to sleep.  And went almost a full week with 0 sleep.  Which is the opposite of what I usually see. It subsided when she stopped, and no other manic symptoms were assessed.

How to dose:

• I always start at 15mg! 7.5mg can be effective for insomnia.  But this is not an effective antidepressant dose, and I am mostly using it for depression with insomnia, and feel that unless other specific issues exist, the risk of mirtazapine does not justify its use for insomnia treatment alone. (30mg starting dose is tolerable and is what some sources recommend but will cause an increase in AM tiredness).

Side effects:

• As discussed above: oversedation, issues waking up, tired during the day, appetite increase, weight gain, and activation/mania.
• Black box warning for all antidepressants for increase in suicidality for people 24 and younger.

Bottom line:

• Mirtazapine can help with insomnia. Due to the weight gain risk, mirtazapine is not considered first line unless other existing conditions that may benefit from it exist: depression, akathisia, anorexia.
• With clients that have depression with sleep disturbance, I still usually use SSRI + a sleep aid before considering mirtazapine due to the side effects.
• But for the right client I have seen lots of people recover and remit due to mirtazapine, and if you are not using it in your algorithm, then hopefully this post adds a tool to your toolbox!

For a plethora of additional clinical pearls, check out the new “Clinical Psychiatry for the Nurse Practitioner Course”, or if you are interested in starting your very own mental health clinic, check out the other psych course “How to Open a Psychiatric Practice Course” which will walk the nurse practitioner through the steps of opening their very own psychiatric practice.