Remeron (Mirtazapine) Sexual Side Effects
Mirtazapine has minimal to no sexual side effects and may actually improve sexual function in depressed patients, making it an excellent alternative for patients experiencing sexual dysfunction from other antidepressants. 1
Key Clinical Evidence
Sexual Dysfunction Profile
Mirtazapine does not cause sexual dysfunction and is specifically noted as "particularly useful in patients who experience sexual side effects from other antidepressants" 2
In direct comparison studies, mirtazapine-treated patients reported significantly improved sexual function rather than worsening, with sexual problems decreasing from 93.2% at baseline to only 24.6% at study end 3
When depressed women were treated with mirtazapine, desire improved by 41%, arousal/lubrication by 52%, and ease/satisfaction of orgasm by 48%; men showed improvements of 10%, 23%, and 14% respectively in these domains 4
Mechanism Explaining Low Sexual Side Effects
Mirtazapine blocks postsynaptic 5-HT2 and 5-HT3 receptors, which are the specific serotonin receptors responsible for sexual dysfunction caused by SSRIs 4, 5
This unique pharmacological profile provides antidepressant efficacy through alpha-2 antagonism and 5-HT1 receptor-mediated serotonergic enhancement, while avoiding the sexual side effects caused by 5-HT2 receptor stimulation 5
Clinical Application Algorithm
When to Choose Mirtazapine
First-line consideration: Depressed patients with pre-existing sexual dysfunction or those who prioritize maintaining sexual function 2
Switching strategy: When patients develop SSRI-induced sexual dysfunction, switching to mirtazapine results in return of normal sexual function in 58% of patients and significant improvement in another 11%, while maintaining antidepressant response 6
Additional benefits: Particularly valuable when depression is accompanied by anxiety, insomnia, or poor appetite, as mirtazapine "promotes sleep, appetite, and weight gain" 1
Dosing Considerations
Start at 7.5 mg at bedtime, with maximum dose of 30 mg at bedtime 1
The sedating effects (related to H1 antihistamine activity) are actually less frequent at higher doses 5
Important Caveats
Trade-offs to Consider
Weight gain is the primary concern: Mirtazapine causes more weight gain than sertraline, trazodone, or venlafaxine 1
Sedation occurs commonly, especially at lower doses, though this can be therapeutically beneficial for patients with insomnia 1, 2
Rare but serious risk: Agranulocytosis occurs in approximately 1 in 1,000 patients, though it is usually reversible when medication is stopped 2
Comparative Context
In stark contrast, paroxetine has the highest sexual dysfunction rate (70.7%) among all SSRIs 7
Bupropion remains the single best option when sexual function is the primary concern (8-10% sexual dysfunction rate), but it cannot be used in agitated patients or those with seizure disorders 7
SSRIs as a class cause "various gastrointestinal and sexual disturbances" as typical side effects 1, while mirtazapine is specifically noted to avoid these problems 5