What are the patient instructions for taking sildenafil (Viagra)?

Patient Instructions for Taking Sildenafil (Viagra)

Sildenafil should be taken approximately 30-60 minutes before sexual activity, with or without food, though high-fat meals may delay onset of action. 1, 2

Dosing Information

• Starting dose:

  • For erectile dysfunction: 50 mg as needed (can be adjusted to 25-100 mg based on efficacy and tolerability) 3
  • For pulmonary arterial hypertension: 20 mg three times daily, taken 4-6 hours apart 1

• Timing considerations:

  • Take 30-60 minutes before anticipated sexual activity 2
  • Effects can last up to 4 hours, though may remain effective for up to 10 hours 2
  • Can be taken with or without food, though high-fat meals may delay onset of action 2

Important Safety Warnings

• Absolute contraindication: Do not take with nitrate medications (including nitroglycerin in any form, isosorbide mononitrate/dinitrate, or "poppers") due to risk of severe, potentially fatal hypotension 4, 1

  • If taking sildenafil, avoid nitrates for at least 24 hours 4
  • If emergency nitrate administration is needed, it must be done under close medical supervision 4

• Cardiovascular considerations:

  • Use caution if you have unstable angina, recent heart attack or stroke, cardiac failure, uncontrolled hypertension, or impaired cardiac reserve 3
  • Report any chest pain, severe dizziness, or fainting to your doctor immediately 1

Common Side Effects

• Headache, flushing, upset stomach, nasal congestion
• Visual disturbances (temporary blue tinge to vision)
• Dizziness, back pain, muscle pain 3, 1

Special Instructions

• For optimal effectiveness:

  • Ensure adequate sexual stimulation, as sildenafil will not work without it 4, 3
  • Allow sufficient time for onset of action (30-60 minutes) 2
  • If first attempt is unsuccessful, try again on different occasions before concluding it doesn't work 4

• Dose adjustments:

  • If experiencing side effects with 50 mg, consider reducing to 25 mg
  • If 50 mg is insufficient, may increase to 100 mg with doctor's approval 3, 1
  • Elderly patients (>65 years) or those with liver/kidney impairment may need to start with 25 mg 5

When to Contact Your Doctor

• If you experience an erection lasting more than 4 hours (priapism) - this requires immediate medical attention 1
• Sudden decrease or loss of vision or hearing 1
• If medication doesn't work after several attempts with proper usage 4
• Before taking any new medications, as interactions may occur 1

Follow-up Care

• Regular follow-up with your doctor is recommended to assess efficacy, side effects, and any changes in health status or medications 4

Remember that erectile dysfunction may be a sign of underlying cardiovascular disease, so appropriate medical evaluation is important 3.