From the Guidelines
Finasteride and fluoxetine can generally be taken together, as there are no significant known drug interactions between these medications. Finasteride (a 5-alpha-reductase inhibitor used for male pattern baldness and prostate enlargement) and fluoxetine (an SSRI used for depression, anxiety, and other mental health conditions) work through different mechanisms in the body. Finasteride primarily affects hormone pathways by blocking the conversion of testosterone to dihydrotestosterone, while fluoxetine affects serotonin levels in the brain. However, it's essential to note that both medications can potentially cause sexual side effects independently, such as decreased libido or erectile dysfunction, and taking them together might theoretically increase the risk of experiencing these side effects, as seen in studies such as 1 which reports on the adverse effects of 5-alpha-reductase inhibitors.
When starting this combination, you should take each medication as prescribed by your healthcare provider - typically finasteride at 1mg daily for hair loss or 5mg daily for prostate issues, and fluoxetine at the dose prescribed for your specific condition (commonly starting at 20mg daily). Always inform your healthcare provider about all medications you're taking to ensure proper monitoring for any potential side effects or rare interactions that might occur in your specific case. It's also crucial to consider the potential for increased risk of sexual dysfunction when combining these medications, as noted in studies on SSRIs like fluoxetine 1.
Some key points to consider when taking finasteride and fluoxetine together include:
- Monitoring for sexual side effects, as both medications can cause decreased libido, erectile dysfunction, or other sexual issues.
- Informing your healthcare provider about all medications, including supplements and over-the-counter drugs, to minimize the risk of interactions.
- Following the prescribed dosage for both finasteride and fluoxetine to ensure efficacy and minimize side effects.
- Regular follow-up with your healthcare provider to assess the effectiveness of the treatment and address any concerns or side effects that may arise, considering guidelines such as those from 1 for the use of 5-alpha-reductase inhibitors.
Given the information available, the most recent and highest quality study directly relevant to the question of taking finasteride and fluoxetine together is not explicitly provided in the evidence, but based on the general principles of pharmacology and the known effects of these medications, it is recommended to proceed with caution and under medical supervision. The evidence provided, such as 1, discusses the use of second-generation antidepressants, including fluoxetine, but does not directly address the combination of finasteride and fluoxetine. Therefore, the decision to take these medications together should be made on a case-by-case basis, considering the individual's health status, the specific conditions being treated, and the potential risks and benefits.
From the Research
Interaction between Finasteride and Fluoxetine
- There is limited research directly addressing the interaction between finasteride (a 5-alpha-reductase inhibitor) and fluoxetine (a selective serotonin reuptake inhibitor, SSRI) 2, 3, 4, 5, 6.
- Finasteride has been associated with depressive symptoms and anxiety in some studies, which could potentially interact with the effects of fluoxetine, an antidepressant 2.
- One study found that finasteride might induce depressive symptoms, suggesting that patients with a high risk of depression should be prescribed finasteride cautiously 2.
- Another study suggested that finasteride for benign prostatic hyperplasia (BPH) was correlated with erectile dysfunction (ED), but the relationship between finasteride and ED is still controversial 4.
- There is evidence that finasteride use is associated with a potential safety signal for obstructive sleep apnea (OSA), which could be related to the "post-finasteride syndrome" (PFS) and may have implications for patients taking fluoxetine 5.
- A preclinical study found that finasteride cancelled the antidepressant-like actions of olanzapine combined with 17-beta estradiol or fluoxetine in rats forced to swim, suggesting a potential interaction between finasteride and antidepressant medications 6.
Potential Implications for Co-administration
- While there is no direct evidence on the interaction between finasteride and fluoxetine, the potential for finasteride to induce depressive symptoms or exacerbate sexual dysfunction could be relevant for patients taking fluoxetine 2, 4.
- Patients taking finasteride and fluoxetine concurrently should be monitored for potential adverse effects, such as increased risk of depressive symptoms, sexual dysfunction, or sleep disturbances 2, 4, 5.
- Further research is needed to determine the safety and efficacy of co-administering finasteride and fluoxetine 2, 3, 4, 5, 6.