What is the proper approach to counseling a patient about erectile dysfunction (ED) drugs, including risks and contraindications?

Counseling Patients About Erectile Dysfunction Medications: Risks and Contraindications

When counseling patients about erectile dysfunction (ED) medications, physicians must thoroughly discuss absolute contraindications, cardiovascular risk assessment, and potential adverse effects to ensure patient safety and optimize treatment outcomes.

Initial Assessment Before Prescribing

• Perform cardiovascular risk assessment for all men with ED, especially those with cardiovascular disease 1, 2
• Sexual activity is equivalent to walking 1 mile in 20 minutes or climbing 2 flights of stairs in 20 seconds 1
• Men who cannot perform these exercises without symptoms should be referred to a cardiologist before ED treatment 1
• Screen for psychosocial problems that can contribute to ED:
  • Anxiety, depression, relationship issues
  • Drug or alcohol use
  • Prescription medications that may cause ED 1, 2

Absolute Contraindications to Discuss

• Nitrate medications: The most important contraindication for all PDE5 inhibitors 3, 4, 5

  • Include nitroglycerin in any form (tablets, patches, sprays)
  • Isosorbide mononitrate or dinitrate
  • "Poppers" (amyl nitrate/nitrite) 4
  • Combined use can cause dangerous, potentially fatal hypotension

• Specific cardiac medications:

  • Vardenafil is not recommended with Type 1A antiarrhythmics (quinidine, procainamide) or Type 3 antiarrhythmics (sotalol, amiodarone) 5

Important Drug Interactions to Highlight

• Alpha-blockers: Use with caution due to potential for additive hypotensive effects 5

  • Start with lowest PDE5 inhibitor dose
  • Separate dosing times when possible

• CYP3A4 inhibitors: May increase PDE5 inhibitor levels 2, 5

  • Azole antifungals (ketoconazole, itraconazole)
  • Antiretroviral protease inhibitors
  • Macrolide antibiotics (erythromycin, clarithromycin)
  • Dose adjustment may be required

• Alcohol: Acts as a vasodilator and can increase hypotensive effects 3

  • Substantial consumption (≥5 units) with tadalafil can increase orthostatic symptoms
  • May cause increased heart rate, decreased standing blood pressure, dizziness, headache

Potential Adverse Effects to Discuss

• Common side effects:

  • Headache, flushing, dyspepsia, nasal congestion, dizziness 6, 7
  • Usually mild and transient

• Vision-related concerns:

  • Risk of non-arteritic anterior ischemic optic neuropathy (NAION) 3, 4
  • Advise patients to seek immediate medical attention for sudden vision loss
  • Higher risk in patients with "crowded disc," age >50, diabetes, hypertension, CAD

• Hearing-related concerns:

  • Sudden decrease or loss of hearing, sometimes with tinnitus and dizziness 3, 4
  • Advise seeking prompt medical attention if these symptoms occur

• Priapism:

  • Erections lasting >4 hours require emergency medical attention 3
  • Can cause irreversible damage to erectile tissue if not treated promptly
  • Higher risk in patients with sickle cell anemia, multiple myeloma, leukemia, or penile anatomical deformations

Medication-Specific Counseling

• Sildenafil/Vardenafil:

  • Take approximately 1 hour before sexual activity
  • Duration of action 4-5 hours
  • Fatty meals may delay absorption and reduce effectiveness 6

• Tadalafil:

  • Can be taken as needed (30 minutes before activity) or daily
  • Longer duration of action (up to 36 hours) allows more spontaneity 3, 7
  • Daily dosing can be taken without regard to timing of sexual activity

• Avanafil:

  • Faster onset of action
  • May be taken as soon as 15 minutes before sexual activity 8

Treatment Algorithm

1. First-line therapy: PDE5 inhibitors

   • Start with conservative dosing and titrate as needed 1
   • Consider an adequate trial as at least 5 separate occasions at maximum dose before declaring ineffective 1
   • If first PDE5 inhibitor fails, try a different one

2. Second-line options (if PDE5 inhibitors fail):

   • Intraurethral alprostadil suppositories
   • Intracavernous injection therapy
   • Vacuum constriction devices 1

3. Third-line therapy:

   • Penile prosthesis implantation 1

Important Counseling Points

• ED medications offer no protection against sexually transmitted diseases 3
• Lifestyle modifications can improve ED: smoking cessation, weight loss, physical activity, limiting alcohol 1, 2
• ED may be a marker for underlying cardiovascular disease requiring evaluation 2
• Medications that commonly cause ED include antihypertensives, NSAIDs, antacids, and psychiatric medications 9

By following this comprehensive counseling approach, clinicians can ensure patients are well-informed about ED medication risks and contraindications, leading to safer and more effective treatment outcomes.