A key side effect of the FGFR inhibitor erdafitinib is central serous retinopathy, presenting as blurred vision. Standard of care involves a baseline ophthalmologic exam before starting treatment. If blurred vision occurs, treatment should be held immediately, but the condition is typically reversible and manageable with dose reduction.

Patients report a temporary, fully reversible blue-gray tint to their vision. This occurs because the drug's target, GSK, is present in eye photoreceptors. Rather than a major concern, this manageable 'nuisance side effect' serves as a real-time biological marker that the drug is successfully engaging its target systemically.

A subtle but significant quality-of-life benefit of oral SERDs over AIs is their mechanism allows for the safe use of topical vaginal estrogens. This is a major advantage for younger patients who struggle with genitourinary symptoms but cannot use estrogens with AIs due to the risk of systemic absorption and spillover effects.

Transdermal estradiol is gaining renewed attention as an ADT option. Recent trials show it is non-inferior to standard LHRH analogs, offering a different side effect profile. This allows clinicians to trade side effects like hot flashes for gynecomastia, enabling more personalized treatment decisions.

Nurses can proactively educate patients that if ocular side effects occur, they will likely manifest around the second cycle, between days 10 and 14. This specific timing helps manage patient anxiety and ensures prompt reporting and intervention.

With multiple FDA-approved oral SERDs available, clinical decision-making is heavily influenced by their distinct side effect profiles. Elacestrant predominantly causes nausea, while iminoralestrant causes diarrhea. This distinction is a primary factor in tailoring treatment to individual patients.

A significant, immediate use for adjuvant oral SERDs like gerodestrant will be for patients who cannot tolerate the arthralgias and other side effects of standard aromatase inhibitors (AIs). This addresses a large and challenging clinical problem, positioning SERDs as a key alternative for maintaining long-term adherence to endocrine therapy.

While both approved oral SERDs are well-tolerated, they have distinct gastrointestinal side effect profiles. Elacestrant is more associated with upper GI issues like nausea (mitigated by taking it with food), whereas imlunestrant is linked to lower GI toxicity like diarrhea. This helps in drug selection and proactive patient counseling.

Unlike some endocrine therapies, oral SERDs used in premenopausal women require concurrent ovarian suppression (e.g., with a GnRH agonist). This is a critical safety measure to mitigate the risk of developing ovarian cysts, a potential side effect of using these agents without adequately suppressing ovarian function.