Mirtazapine Administration Time
Mirtazapine should be administered once daily in the evening, preferably prior to sleep. 1
Rationale for Evening Dosing
The FDA-approved labeling explicitly recommends evening administration before bedtime 1, which aligns with the drug's pharmacological profile and clinical benefits:
Sedative properties are leveraged therapeutically - The National Comprehensive Cancer Network recognizes that mirtazapine's sedating effects can effectively address sleep disturbances that commonly accompany depression 2
Particularly beneficial for patients with comorbid insomnia - Mirtazapine is specifically recommended by the National Comprehensive Cancer Network for patients experiencing both depression and insomnia 2
Elimination half-life supports once-daily dosing - With a half-life of 20-40 hours, mirtazapine is well-suited for single daily administration 3, 4
Dosing Schedule
Dose adjustments should not occur more frequently than every 1-2 weeks to allow adequate time for response evaluation 1
Maximum dose: 45 mg daily 1
Clinical Benefits of Evening Administration
Early improvement in sleep and anxiety symptoms - Sleep disturbances and anxiety may improve within the first week of treatment, even before the full antidepressant effect emerges at 2-4 weeks 3, 4
Reduces need for additional hypnotic medications - The sedative effects when dosed at bedtime may eliminate the need for separate sleep aids 4
Minimizes daytime sedation concerns - By timing administration before sleep, the sedating effects are less likely to interfere with daytime functioning 6
Important Precautions
Obstructive sleep apnea warning - Exercise caution in patients with obstructive sleep apnea, as mirtazapine may worsen this condition according to the American Academy of Sleep Medicine 2
Common sedation-related side effects - Drowsiness and excessive sedation are more common with mirtazapine than placebo, making evening dosing particularly appropriate 6
Gender considerations - While evening administration is recommended for both sexes, women may require higher doses than men to achieve equivalent therapeutic effects 2