Olanzapine and Sexual Dysfunction
Olanzapine is associated with sexual dysfunction, not increased sexual expression—it causes decreased sexual function in approximately 35-40% of patients, manifesting as reduced libido, arousal difficulties, and orgasm problems. 1, 2
Evidence for Sexual Dysfunction with Olanzapine
The available evidence consistently demonstrates that olanzapine impairs rather than enhances sexual function:
In the EIRE study, 35.3% of patients on olanzapine experienced sexual dysfunction, which was comparable to haloperidol (38.1%) and lower than risperidone (43.2%), but substantially higher than quetiapine (18.2%). 2
Sexual dysfunction with olanzapine appears dose-related, with higher doses associated with greater impairment of sexual function. 2
Female patients with schizophrenia on olanzapine showed 83% prevalence of sexual dysfunction, with significant reductions in pleasure, frequency of sexual contacts, desire, arousal, and orgasm. 3
Mechanism of Sexual Dysfunction
The sexual side effects occur through multiple pathways:
Olanzapine elevates prolactin levels, which suppresses hypothalamic GnRH and reduces pituitary gonadotropin secretion, ultimately impairing gonadal steroidogenesis in both sexes. 4
Hyperprolactinemia can cause galactorrhea, amenorrhea, gynecomastia, and impotence as direct clinical manifestations. 4
Dopamine antagonism combined with prolactin elevation contributes significantly to sexual dysfunction. 5
In clinical trials, 30% of adults treated with olanzapine showed changes from normal to high prolactin concentrations compared to 10.5% on placebo. 4
Clinical Manifestations
The FDA label documents specific reproductive side effects:
Sexual function-related events occurred in 2% of patients (including anorgasmia, delayed ejaculation, erectile dysfunction, decreased libido, and sexual dysfunction). 4
Menstrual-related events occurred in 2% of females (amenorrhea, hypomenorrhea, menstruation delayed, oligomenorrhea). 4
Breast-related events occurred in 0.7% of females and 0.2% of males (breast discharge, enlargement, galactorrhea, gynecomastia). 4
Comparative Profile
Olanzapine ranks in the middle range for sexual dysfunction among antipsychotics: risperidone > haloperidol > olanzapine > quetiapine > aripiprazole. 6
Important Clinical Caveat
There is no evidence that olanzapine increases sexual expression or libido—the documented effects are uniformly in the direction of sexual impairment. Any apparent increase in sexual behavior in a patient on olanzapine would more likely represent:
- Improvement in underlying psychotic symptoms that were previously inhibiting normal function
- Disinhibition from the underlying psychiatric condition
- A separate clinical issue unrelated to the medication
Monitor patients for sexual dysfunction proactively, as it significantly impacts quality of life and medication adherence. 6, 5