Penegra is a brand-name medication that contains sildenafil as its active ingredient. It belongs to the therapeutic class of erectile dysfunction (ED) treatments and is supplied as oral tablets (pill) in strengths of 25 mg, 50 mg, and 100 mg. In Hong Kong, Penegra is classified as a prescription-only medicine and is regulated by the Hong Kong Medicines and Healthcare Products Regulatory Authority (HKMA).
Sildenafil is a phosphodiesterase-5 (PDE5) inhibitor. By blocking the PDE5 enzyme, it increases levels of cyclic guanosine monophosphate (cGMP) in the smooth muscle of the penile arteries. Elevated cGMP leads to relaxation of these muscles, allowing increased blood flow into the penis when sexual stimulation occurs. The drug’s onset of action typically begins within 30-60 minutes, peaks around 1-2 hours, and its effects last for up to 4-6 hours. Sildenafil is absorbed orally with an estimated bioavailability of about 40 % and is metabolised primarily by the liver enzyme CYP3A4.
Penegra is approved in Hong Kong for the treatment of erectile dysfunction in adult men. It is intended for use on an as-needed basis before sexual activity. The medication is not approved for routine daily use or for other medical conditions unless specifically prescribed for those indications by a qualified clinician.
Pulmonary arterial hypertension (PAH). Sildenafil has been studied for PAH under the brand name Revatio. While not approved for this indication in Hong Kong under the Penegra label, some clinicians prescribe it off-label for PAH after careful risk-benefit assessment. Disclaimer: Off-label use must be supervised by a qualified healthcare professional and is not endorsed by regulatory agencies for this product.
Benign prostatic hyperplasia (BPH) symptoms. Small studies suggest potential improvement in lower urinary tract symptoms, but evidence remains limited and the use is experimental.
Absolute contraindications
Relative contraindications / cautions
Special populations
These effects are usually mild and transient. If they persist or worsen, patients should discuss dosage adjustments with their prescriber.
If individual health factors (e.g., liver or kidney disease) are present, dosing should be individualized by a healthcare professional.
Routine laboratory monitoring is not required for most patients. However, clinicians may:
Patients should contact their provider promptly if they experience a painful erection lasting more than four hours, sudden vision or hearing changes, or unexplained chest pain.
This article provides educational information about Penegra (sildenafil) and is not a substitute for professional medical advice. Treatment decisions, including use for unapproved indications, must be made under the guidance of a qualified healthcare provider. The content is intended for informational purposes and does not constitute medical recommendations. Always consult a physician before starting, stopping, or changing any medication regimen.
Alcohol in moderate amounts may increase the likelihood of dizziness or hypotension and can impair sexual performance. It is advisable to limit alcohol consumption when planning to use Penegra.
A high-fat meal can delay the drug’s absorption, resulting in a slower onset and reduced peak concentration. For more reliable results, take the tablet with a light meal or on an empty stomach.
Seek immediate medical attention. Priapism can cause permanent tissue damage if not treated promptly.
Men with well-controlled hypertension may use Penegra, but those on nitrates or with unstable blood pressure should avoid it. Always discuss cardiovascular status with your doctor before starting therapy.
It is generally contraindicated in the first six weeks after a myocardial infarction due to the risk of cardiac stress. A cardiologist should evaluate suitability on a case-by-case basis.
No. Penegra is intended for use on an as-needed basis before sexual activity, not for daily dosing.
Patients may notice a blue-tinted vision, heightened light sensitivity, or blurred vision. These effects are usually temporary and resolve after the medication wears off.
Yes. Penegra is a prescription-only medication in Hong Kong and must be prescribed by a licensed healthcare professional.
Keep the tablets in a cool, dry place away from direct sunlight. If ambient temperatures exceed 30 °C, store the medication in a climate-controlled area or in the original container with a desiccant.
Co-administration is permissible, but the combination should be reviewed by a physician to avoid unforeseen interactions or duplicate effects.
