Avanafil

Avanafil: A Comprehensive Guide for Australian Patients

Basic Product Information

Mechanism of Action

In Simple Terms: Avanafil helps men with erectile dysfunction (ED) by increasing blood flow to the penis, making it easier to achieve and maintain an erection during sexual stimulation. It works by relaxing blood vessels in the penis, allowing more blood to enter when a man is sexually aroused.

For Specialists: Avanafil is a selective phosphodiesterase type 5 (PDE5) inhibitor. By inhibiting PDE5, avanafil enhances the effect of endogenous nitric oxide, increasing cyclic guanosine monophosphate (cGMP) levels in corpus cavernosum smooth muscle. This leads to smooth muscle relaxation and inflow of blood, facilitating erection in the presence of sexual stimulation.

Pharmacokinetics

• Absorption: Rapidly absorbed after oral administration. Peak plasma concentrations occur in 30–45 minutes (range: 20–60 minutes).
• Onset of Action: Effects may be noticed as early as 15 minutes after dosing.
• Metabolism: Primarily metabolised in the liver via CYP3A4 and to a lesser extent CYP2C9 enzymes.
• Elimination: Eliminated mostly via faeces (approx. 63%) and urine (approx. 21%) mainly as metabolites.
• Half-Life: About 6–17 hours (mean terminal half-life).
• Duration of Action: Up to 6 hours; some efficacy may persist for longer.

Use in Everyday Life & Best Practices

In Australia, avanafil is commonly used by adult men diagnosed with erectile dysfunction. Its rapid onset allows for more spontaneity compared to some older ED medications.

• Usual Dose: 100 mg taken as needed, 15–30 minutes before sexual activity.
• Maximum Dose: 200 mg per day
• Starting Dose: For some people, especially older adults or those with liver or kidney impairment, 50 mg may be sufficient.
• Do Not Take More Than Once a Day: Taking more than the recommended dose can increase the risk of side effects without improving efficacy.
• Sexual Stimulation Required: Avanafil does not cause an erection unless there is sexual stimulation.

Dosing: Morning vs Evening

• Avanafil can be taken at any time of day. Unlike some ED medications, it does not need to be taken regularly but should be used only when needed, before sexual activity.
• Morning Use: Offers the chance for intimacy earlier in the day; helpful for those with busy evening schedules or who find morning time preferable.
• Evening Use: Most common. May align better with natural sexual routines and partner schedules.
• Try to take avanafil at the same interval before planned activity (e.g., always 15–30 minutes prior), regardless of time of day, for best results.
• Consistency enhances confidence, but flexibility is an advantage of avanafil's rapid action.

Taking with Food or on an Empty Stomach

• With or Without Food: Avanafil can be taken with or without food.
• Meals: A high-fat meal may delay its absorption and the time to effect by approximately 1 hour.
• Australian Dietary Context: Taking avanafil after a light breakfast or lunch (e.g., toast, cereal, salad) will not significantly affect onset. Avoid large, fatty meals immediately before use.

Interaction Warnings

Indications

Dosing According to Clinical Indications

Safety Profile & Side Effects

• Common side effects (≥1%):
  • Headache
  • Flushing (warmth, redness in face)
  • Nasal congestion
  • Dizziness
  • Back pain
  • Sinus discomfort
• Uncommon/Rare side effects (<1%):
  • Vision changes (colour tinge, blurred vision)
  • Increased heart rate or palpitations
  • Prolonged erection (>4 hours) – Priapism; seek urgent treatment
  • Sudden hearing loss; rare, report immediately
  • Allergic reactions (rash, swelling)
• Warnings:
  • Not to be used with nitrate medications
  • Use caution in those with heart disease, uncontrolled hypertension, liver or kidney impairment
  • If chest pain occurs during sex, stop immediately and seek urgent care

Guidelines for Proper Use: Pharmacist Advice

• Only take avanafil when planning sexual activity; not for regular/daily use
• Store in a cool, dry place, below 25°C, out of reach of children
• Do not use after the expiry date
• Tell your GP or pharmacist about all medications, supplements, and herbal products you use
• Inform your doctor if you experience prolonged side effects or allergic reactions
• Maintain a healthy lifestyle (diet, exercise, moderation in alcohol) for best results
• Discuss with a healthcare professional before use if you have significant heart, liver, or kidney conditions
• Refer to TGA for complete safety and update information

Alternative Treatment Options

• Sildenafil (Viagra® and generics): Widely available, longer onset (30–60 min), lasts up to 4–6 hours. May be slightly more affected by food. Often first-line due to cost and familiarity.
  • Pros: Long clinical track record, cost-effective options, available on PBS for specific indications.
  • Cons: Frequent headaches, greater food effect, possible visual side effects.
• Tadalafil (Cialis® and generics): Long duration (up to 36 hours), can be taken daily in low doses or as needed.
  • Pros: Lasts longer, suitable for regular/anticipated activity, minimal food effect.
  • Cons: Longer persistence of side-effects, costlier, not suitable for everyone.
• Vardenafil (Levitra®): Rapid onset, similar to avanafil, but more affected by fatty meals.
  • Pros: Effective alternative if sildenafil doesn’t work.
  • Cons: Less convenient with high-fat meals, not commonly prescribed in Australia.
• Non-drug Options: Psychotherapy, device-aided therapy (vacuum pumps), intracavernosal injections, surgical implants (for severe cases).

Legal, Registration & Reimbursement Status in Australia

• Therapeutic Goods Administration (TGA) Approval: Yes
• Prescription Only: Schedule 4 (S4); must be prescribed by an Australian registered health practitioner
• Reimbursement: Not covered by the Pharmaceutical Benefits Scheme (PBS) for most patients
• Availability: Widely available through community pharmacies by prescription
• Not available over the counter or via the National Disability Insurance Scheme (NDIS) as a standard benefit