• Nitrate Medications: Do not use sildenafil if you are taking nitric oxide donors, including organic nitrates or nitrites, as it can cause a dangerous drop in blood pressure.
• Allergies: Avoid sildenafil if you have a known allergy to it.
• Guanylate Cyclase (GC) Stimulators: Do not use if you are taking medications like riociguat, as it can also cause a significant drop in blood pressure.

• Timing: Take sildenafil approximately 30 minutes to 1 hour before sexual activity. It can be taken with or without food.
• Frequency: Do not take more than once in a 24-hour period.

• Nitrates, Alpha-Blockers, and Antihypertensives: These can cause a sudden drop in blood pressure when taken with sildenafil.
• CYP3A4 Inhibitors: Medications like ritonavir, ketoconazole, itraconazole, and erythromycin can increase sildenafil levels in the bloodstream, leading to potential side effects.

• Headache: This is the most commonly reported side effect.
• Flushing: A feeling of warmth, especially in the face, neck, or chest.
• Indigestion: Some users may experience stomach discomfort or pain.
• Nasal Congestion: A stuffy nose can occur.
• Dizziness: Some users may feel lightheaded or dizzy.
• Visual Disturbances: Changes in vision, such as blurred vision or a blue tinge to vision, can occur.

• Sudden Vision Loss: In rare cases, sildenafil can cause sudden vision loss in one or both eyes.
• Sudden Hearing Loss: Some users may experience a sudden decrease or loss of hearing.
• Priapism: An erection that lasts more than 4 hours requires immediate medical attention to prevent long-term damage.
• Severe Allergic Reactions: Symptoms may include rash, itching/swelling, severe dizziness, or trouble breathing.

• Medical History: Always inform your healthcare provider about all medications you are taking, including over-the-counter drugs, vitamins, and supplements. This helps to avoid potential drug interactions and side effects.

Sildenafil: This medication is clinically proven to help achieve and maintain erections by increasing blood flow to the penis during sexual arousal. For more information, you can refer to the FDA Sildenafil Information.

Apomorphine: This medication works differently by stimulating dopamine receptors in the brain to enhance sexual arousal and response. While it has shown effectiveness in treating erectile dysfunction, it is not as widely studied or approved for this use in all regions, including the United States. For more details, you can check the FDA Apomorphine Information.