Does fenofibrate exacerbate erectile dysfunction (ED) and can a lower dose be used, and will discontinuing doxepin (Sinequan) and adding modafinil (Provigil) alleviate daytime sleepiness?

Management of Sleep Maintenance Issues and Erectile Dysfunction

Discontinuing doxepin and adding modafinil 100mg in the morning is an appropriate strategy to address daytime sleepiness while maintaining sleep, and reducing the fenofibrate dose from 160mg to 67mg may help alleviate medication-related erectile dysfunction.

Modafinil for Daytime Sleepiness

Modafinil is an effective treatment for excessive daytime sleepiness with several advantages over traditional stimulants:

• The American Academy of Sleep Medicine strongly recommends modafinil for treating excessive daytime sleepiness 1
• For elderly patients, starting with 100mg once daily in the morning is recommended, with increases at weekly intervals as needed 1
• Modafinil significantly improves daytime sleep latency and reduces excessive daytime sleepiness compared to placebo 1, 2
• Unlike amphetamines and methylphenidate, modafinil has a low abuse potential and lacks rebound phenomena after treatment withdrawal 1, 2

Adding modafinil 100mg in the morning as proposed is consistent with guidelines and should effectively address the daytime sleepiness caused by doxepin.

Discontinuing Doxepin

Discontinuing doxepin is appropriate given the side effects experienced:

• Doxepin (a TCA) is known to cause daytime sleepiness and sexual dysfunction including erectile dysfunction
• Abruptly stopping doxepin is reasonable since you're maintaining mirtazapine 11.25mg, which will continue to provide sleep maintenance effects

Fenofibrate and Erectile Dysfunction

Regarding fenofibrate and erectile dysfunction:

• While not extensively documented in the provided evidence, fibrates as a class can contribute to erectile dysfunction through their effects on lipid metabolism and potentially hormonal pathways
• Reducing the dose from 160mg to 67mg is a reasonable approach to maintain lipid-lowering benefits while potentially reducing the side effect of erectile dysfunction
• The lower dose may still provide adequate lipid control while minimizing adverse effects

Monitoring and Follow-up

After implementing these changes:

• Assess sleep quality, daytime alertness, and erectile function after 2 weeks as proposed
• Monitor for common side effects of modafinil including headache, nausea, and nervousness 1
• If daytime sleepiness persists, consider increasing modafinil to 200mg daily, which is the standard recommended dose for most adults 1
• If erectile dysfunction persists despite the fenofibrate dose reduction, further evaluation of other contributing factors may be warranted

Potential Benefits Beyond Primary Concerns

Interestingly, modafinil may offer additional benefits:

• Some case reports suggest modafinil may actually improve sexual function in patients with antidepressant-induced sexual dysfunction 3
• Modafinil improves cognitive function and executive function, which may provide additional quality of life benefits 4

This treatment plan addresses both the sleep maintenance issues and erectile dysfunction while maintaining therapeutic efficacy for the underlying conditions requiring these medications.