Avanafil instructions for use, how to take?

Avanafil is one of the most modern pharmacological agents developed for the symptomatic treatment of Erectile Dysfunction (ED) in adult men. It represents a newer generation of medications belonging to the esteemed class of Phosphodiesterase Type 5 (PDE-5) inhibitors. The key differentiator and primary advantage of Avanafil, which sets it apart from its counterparts, is its exceptionally rapid onset of action.

The drug provides reliable and effective support for erectile function but, like all PDE-5 inhibitors, it works exclusively on the condition of sexual stimulation. It is not an aphrodisiac or a hormone; it does not create desire but merely facilitates the physiological response to it.

Due to its ability to be rapidly absorbed and begin working quickly, Avanafil has become a convenient and popular solution for men. It allows for greater spontaneity in intimate relationships, reducing the need for the strict planning required by first-generation drugs, and permits a swift return of control over sexual activity.

Indications for Use of Avanafil

Avanafil has one clear and approved indication: the therapy of erectile dysfunction. This condition is diagnosed as the persistent inability to achieve or maintain a penile erection sufficient for satisfactory sexual intercourse. This problem can significantly impact a man's quality of life, self-esteem, and relationship with his partner.

The drug works by improving hemodynamics (blood flow) in the pelvic region. It helps restore the natural mechanism of filling the corpus cavernosum with blood. It is important to emphasize once more that achieving a firm erection when taking Avanafil requires an initial erotic stimulus and sexual arousal. Without this initial impulse, the drug will have no effect.

How Does Avanafil Work? An In-depth Mechanism

To understand how Avanafil works, it is necessary to review the biochemical cascade underlying a normal erection:

1. Stimulation and NO: When a man experiences sexual arousal, nerve endings in the corpus cavernosum of the penis release nitric oxide (NO).

2. Enzyme Activation: Nitric oxide acts as a signaling molecule, activating an enzyme called guanylate cyclase.

3. cGMP Production: Guanylate cyclase, in turn, converts guanosine triphosphate (GTP) into cyclic guanosine monophosphate (cGMP).

4. Role of cGMP (Vasodilation): cGMP is the key executor. It causes the smooth muscle cells in the walls of the penile arteries and within the erectile tissue itself to relax.

5. Erection: This relaxation leads to vasodilation (a dramatic widening of the arteries). Blood under pressure begins to flow massively into the penis, filling it like a sponge. Simultaneously, the veins that drain the blood are compressed, trapping the blood inside. This creates a firm erection.

6. The "Brake" (PDE-5): The body has a natural regulator—an enzyme called Phosphodiesterase Type 5 (PDE-5). Its job is to destroy (hydrolyze) cGMP to end the erection after sexual activity is complete.

In men with ED, this mechanism is often impaired.

Avanafil's Role: Avanafil is a potent and highly selective inhibitor of PDE-5. This means it specifically blocks this enzyme, with minimal effect on other PDE types in the body (e.g., PDE-6 in the retina, which reduces the risk of vision-related side effects, or PDE-11).

By blocking PDE-5, Avanafil prevents it from destroying cGMP. As a result, during stimulation, cGMP levels remain higher for longer, muscle relaxation is sustained, and blood flow remains intense.

Key Advantage: The unique molecular structure of Avanafil allows it to be absorbed and reach peak concentration in the blood extremely quickly. An effect is often observed within just 15-30 minutes of ingestion, which is significantly faster than sildenafil or vardenafil.

How to Take Avanafil Correctly

• Dosage: The choice of dose is individualized and depends on efficacy, tolerability, and a doctor's recommendation.

  • 100 mg: This is the standard recommended starting dose for most men.

  • 200 mg: The maximum daily dose. It is prescribed if 100 mg did not produce a sufficient effect but was well-tolerated.

  • 50 mg: The minimum dose. It is recommended for elderly patients, patients with mild liver or kidney impairment, or those taking weak inhibitors of the CYP3A4 enzyme.

• Timing: Thanks to its rapid onset, the tablet should be taken only 15-30 minutes before planned sexual activity.

• Duration of Action: The effective "window of opportunity" (the time during which the drug helps achieve an erection in response to stimulation) lasts for up to 6 hours.

• Method of Administration: The tablet should be swallowed whole with a full glass of water. Avanafil can be taken with or without food.

  • Food's Impact: Unlike some other PDE-5 inhibitors, food intake (even a high-fat meal) does not have a clinically significant effect on the absorption of Avanafil at 50 mg and 100 mg doses. However, with the maximum 200 mg dose, a very high-fat meal may slightly delay the time to peak concentration, but not the overall effectiveness.

• Frequency of Use: It is strictly forbidden to take more than one tablet (regardless of dose) per day (within a 24-hour period).

What are the Contraindications for Avanafil?

1. Nitrate Use (ABSOLUTE CONTRAINDICATION): This is the most severe prohibition. The simultaneous use of Avanafil with organic nitrates (e.g., nitroglycerin, isosorbide dinitrate, used for angina/chest pain) or any nitric oxide donors is strictly forbidden. Both drugs cause vasodilation, and their combination leads to a synergistic effect—a sudden, uncontrolled, and life-threatening drop in blood pressure (collapse).

2. Severe Cardiovascular Disease: The drug is contraindicated for patients for whom sexual activity is inadvisable due to cardiac risk. This includes patients with a recent (within the last 6 months) heart attack or stroke, or those with unstable angina, uncontrolled arrhythmia, or severe heart failure.

3. Allergy: A known hypersensitivity or allergic reaction to avanafil or any of the excipients in the tablet.

4. Severe Liver or Kidney Disease: As Avanafil is metabolized by the liver (primarily by the CYP3A4 enzyme) and excreted by the kidneys, its use is contraindicated in severe hepatic or renal failure (including dialysis) due to the risk of toxic accumulation.

Avanafil: What are the Side Effects?

Most of Avanafil's side effects are related to its primary mechanism (vasodilation) and are usually mild to moderate and short-lived.

Most Common Side Effects:

• Headache: The most frequent complaint.

• Facial Flushing: A sudden feeling of warmth and redness of the face.

• Nasal Congestion (Rhinitis): Swelling of the nasal lining.

• Dizziness.

• Nausea.

• Back pain or muscle pain (myalgia).

Avanafil's high selectivity for PDE-5 means that side effects related to other PDEs (such as the color-vision changes seen with sildenafil) are significantly less common.

Serious (Rare) Side Effects: If any of these symptoms occur, urgent medical attention is required:

• Priapism: A painful erection lasting longer than 4 hours. This is a medical emergency that can lead to irreversible damage to the penile tissue.

• Chest pain, severe palpitations, a sharp drop in blood pressure (especially when interacting with other drugs).

• Sudden vision loss in one or both eyes (a sign of NAION - Non-Arteritic Anterior Ischemic Optic Neuropathy).

• Sudden hearing loss.

Avanafil Interactions with Other Medications

• Nitrates: As stated above, strictly prohibited.

• Potent CYP3A4 Inhibitors: Drugs that block the enzyme that breaks down Avanafil. These include antifungal agents (ketoconazole, itraconazole), macrolide antibiotics (clarithromycin, telithromycin), and protease inhibitors (HIV drugs, e.g., ritonavir). Their concurrent use with Avanafil is contraindicated as it can increase its concentration in the blood tenfold or more.

• Antihypertensives (Blood Pressure Meds): Avanafil itself has a mild vasodilating effect. Taking it with other blood pressure drugs, especially alpha-blockers (used for prostate enlargement), can amplify this effect and cause dizziness or orthostatic hypotension. Medical supervision is required.

• Grapefruit Juice: This is a moderate CYP3A4 inhibitor and should be avoided when taking Avanafil.

Special Recommendations

• Alcohol: Consuming alcohol with Avanafil can enhance the side effects of both substances. Specifically, it increases the risk of dizziness, headache, and orthostatic hypotension (a drop in blood pressure upon standing). Furthermore, alcohol itself is a central nervous system depressant and can worsen erectile function, thereby negating the drug's effect.

• Driving and Operating Machinery: Because Avanafil can cause dizziness or temporary vision changes, caution is advised. Do not drive or operate complex machinery until you are sure the drug does not negatively affect your reactions.

Storage

Store Avanafil in its original packaging at room temperature (not exceeding 30°C / 86°F). The location must be dry, protected from moisture and direct sunlight, and absolutely out of the reach of children.

Summary

Avanafil is a significant achievement in modern pharmacology for the treatment of erectile dysfunction. Its main advantages are an exceptionally rapid onset of action (15-30 minutes), high efficacy, and a favorable safety profile due to its high selectivity. It restores not only physiological function to men but also confidence and spontaneity in their sexual lives.

However, like any potent medication, it demands a responsible approach. Consultation with a physician before use is mandatory. Only a professional can assess your cardiovascular health, rule out dangerous contraindications (especially nitrate use), and select the optimal and safe dosage.