From the Research
Reducing tamoxifen to 5 mg daily is a reasonable approach if the standard 10 mg dose is causing intolerable side effects. While the standard tamoxifen dose for breast cancer treatment is typically higher, studies have shown that lower doses can still provide significant estrogen receptor blockade while potentially reducing side effects like hot flashes, vaginal dryness, mood changes, and thromboembolic risks 1. The effectiveness of the lower dose may be somewhat reduced compared to standard dosing, but some therapy is better than discontinuing treatment altogether due to toxicity. Before reducing the dose, consider trying supportive measures for side effect management, such as:
- SSRIs for hot flashes (avoiding paroxetine and fluoxetine due to drug interactions)
- Vaginal moisturizers for dryness
- Exercise for fatigue If side effects persist despite the dose reduction to 5 mg daily, alternating day dosing (10 mg every other day) could be considered as another option before completely discontinuing therapy 2. Always discuss these changes with the prescribing oncologist to ensure the modified regimen still provides adequate protection against cancer recurrence for the individual patient's risk profile. It's also important to note that newer compounds, such as raloxifene, have a similar SERM profile to tamoxifen but are neutral on the uterus, which may be a consideration for some patients 3. However, the primary concern is to balance the benefits of tamoxifen therapy with the potential risks and side effects, and to prioritize the patient's quality of life and overall health outcomes.