For what situations are trazodone or mirtazapine commonly used in insomnia, and what are potential risks?

• A. Off-label for sleep (often with comorbid depression); risks include daytime sedation, anticholinergic effects (mirtazapine), orthostatic hypotension, weight gain.
• B. First-line treatment for insomnia; risks include dependence and withdrawal.
• C. Used primarily for REM sleep behavior disorder; risks include arrhythmias.
• D. Only used for circadian rhythm disorders; risks include photosensitivity.

Answer: (A)

Trazodone and mirtazapine are sedating antidepressants that are commonly used off-label to help with sleep, especially when insomnia occurs alongside depression or anxiety. They’re not first-line treatments for primary insomnia, but they can improve sleep continuity and reduce time to fall asleep in patients who also need mood management.

The risks to watch for include daytime sedation, which can linger into the day and affect alertness and functioning. Orthostatic hypotension is another consideration, since these medications can lower blood pressure when you stand up, leading to dizziness or faintness. Weight gain is a notable side effect with mirtazapine due to increased appetite and metabolic changes. Mirtazapine can also have anticholinergic effects, though these tend to be milder than with some other agents. Trazodone carries a rare risk of priapism, so patients should be aware of this possibility and seek care if unusual penile erections occur.

These drugs aren’t intended for REM sleep behavior disorder or circadian rhythm disorders specifically, which is why their use for those conditions isn’t appropriate in typical treatment guidelines.