Management of Erectile Dysfunction in Patients Taking Anastrozole
Start with oral PDE5 inhibitors (sildenafil, tadalafil, vardenafil, or avanafil) as first-line therapy for ED in patients on anastrozole, as these agents demonstrate equivalent efficacy and are the standard of care regardless of the underlying etiology. 1, 2
Initial Treatment Approach
Begin with a PDE5 inhibitor at standard dosing and titrate upward as needed to optimize efficacy. 1 All four available agents show similar success rates, so selection can be based on patient preference regarding timing and duration of action 1, 2
Provide explicit instructions on proper use: sexual stimulation is required for effectiveness, and timing varies by medication (sildenafil/vardenafil: 30-60 minutes before intercourse; tadalafil: up to 36 hours window; avanafil: 15-30 minutes) 1
Before declaring treatment failure, verify the patient is using the medication correctly with adequate timing and sexual stimulation, as education about proper dosing can restore effectiveness 1
Mandatory Baseline Evaluation
Measure morning total testosterone level to identify hypogonadism, which commonly contributes to ED and may be exacerbated by aromatase inhibitor therapy 1, 3
Perform cardiovascular risk assessment before initiating PDE5 inhibitors, as ED is an independent marker for cardiovascular disease requiring appropriate screening 1, 2
Check fasting glucose/HbA1c and lipid profile to identify cardiovascular risk factors 1, 3
Absolute contraindication: Do not prescribe PDE5 inhibitors to patients taking nitrates (wait 24 hours after sildenafil/vardenafil or 48 hours after tadalafil before nitrate administration) 2, 4
Special Considerations for Anastrozole Patients
Anastrozole causes known side effects including joint stiffness, arthralgias, vasomotor symptoms, and vaginal dryness 5, which may compound sexual dysfunction beyond ED alone
If testosterone is low in the setting of anastrozole therapy, consider that aromatase inhibitors can affect hormonal balance; testosterone replacement in combination with PDE5 inhibitors may benefit non-responders 1
Monitor bone health: Anastrozole increases bone loss risk, requiring baseline bone mineral density assessment and consideration of bone-protective agents 5
Second-Line Options if PDE5 Inhibitors Fail
Try a different PDE5 inhibitor before proceeding to more invasive therapies, though evidence for this strategy is limited 5, 1, 2
Intracavernous injection therapy (alprostadil, papaverine, phentolamine, or combinations) is highly effective as second-line treatment, but requires initial test dose under healthcare provider supervision to determine effective dosing and monitor for prolonged erection 5, 1, 2
Intraurethral alprostadil suppositories are less invasive than injections but have lower efficacy; the first dose must be administered under supervision due to 3% risk of syncope 5, 2
Vacuum constriction devices with vacuum limiters show 90% initial efficacy but drop to 50-64% at 2 years; only devices containing vacuum limiters should be used to prevent penile injury 5, 1, 2
Adjunctive Interventions
Offer psychosexual counseling as an adjunct to medical treatment, particularly given the chronic nature of breast cancer treatment and its psychological impact 1
Address modifiable risk factors: weight loss, increased physical activity, and smoking cessation may improve erectile function 3
Review all medications for agents that contribute to ED (thiazide diuretics, beta-blockers, antidepressants) 2, 6, 7
Common Pitfalls to Avoid
Do not overlook testosterone deficiency, as anastrozole's mechanism of action (aromatase inhibition) can affect hormonal balance beyond its intended breast cancer risk reduction effect 5, 1
Do not prescribe PDE5 inhibitors without screening for nitrate use, as this combination can be fatal 2, 4
Do not declare PDE5 inhibitor failure without optimizing dose, timing, and addressing modifiable factors such as proper sexual stimulation and medication timing 1, 2
Do not ignore that ED may signal underlying cardiovascular disease, requiring appropriate cardiac risk assessment especially in postmenopausal women on anastrozole who already have elevated cardiovascular risk 1, 3
Follow-Up Strategy
Schedule 3-month follow-up after initiating PDE5 inhibitors to assess response and adjust therapy 1
Reassess cardiovascular risk factors periodically, as ED and cardiovascular disease share common pathophysiologic pathways 3
Monitor for anastrozole-related side effects that may compound sexual dysfunction, including vasomotor symptoms and vaginal dryness 5