Udenafil

Key points

• Udenafil is sold in some countries, but it holds no FDA approval.
• It is intended for adult men and is not indicated for use in women.
• The liver clears it rapidly, chiefly through the CYP3A pathway.

How it works

Sexual stimulation triggers nitric oxide release, and cGMP builds up in penile blood vessels. cGMP relaxes the smooth muscle there, so blood flows in. Udenafil blocks PDE5, the enzyme that breaks cGMP down, extending the effect. Without stimulation it does little.

Forms and brands

Udenafil is made as a tablet and sold under the Zudena brand at 100mg. Pharmacy partners in India send orders to Malaysia in discreet packaging.

Safety

Udenafil must not be used with organic nitrates such as nitroglycerin, or by men with severe cardiac failure or unstable blood pressure. Care is needed after a myocardial infarction, stroke or dangerous arrhythmia in the previous six months, and with resting hypotension or hypertension, heart failure, unstable angina or alpha-blocker use. Ketoconazole is another interacting medicine. Dyspepsia, flushing and headache are common; dizziness, slight visual blur and nasal congestion can also occur. Priapism is serious and needs immediate medical attention. Anyone breastfeeding should confirm suitability with a clinician or pharmacist.

What the sources say

• The whole class works through one shared mechanism (StatPearls).
• A PDE5 inhibitor taken with nitrates or nitroglycerin causes excessive preload reduction (StatPearls).
• These drugs are not genuinely selective for PDE5, and most harm comes from cross-reactivity with other PDE isoenzymes (StatPearls).

Further reading

• Erectile dysfunction - healthdirect
• PDE5 Inhibitors - StatPearls (NCBI Bookshelf)
• Udenafil - PubChem
• Udenafil - Medscape