Udenafil

Udenafil is a phosphodiesterase type 5 (PDE5) inhibitor developed in South Korea for erectile dysfunction. It sits in the same pharmacological family as sildenafil and avanafil. Like them, it helps the blood vessels in the penis relax in response to sexual stimulation, so it does not cause an erection on its own and does nothing without sexual excitement. Udenafil is not authorised by the MHRA, so there is no UK SmPC, no UK patient leaflet and no entry on the electronic medicines compendium. Information about it comes mainly from the overseas product label and published studies, some of them funded by the manufacturer, so it is less complete than for licensed UK medicines.

Udenafil has no UK marketing authorisation and no UK-authorised brand. The licensed UK options for erectile dysfunction are other PDE5 inhibitors, such as sildenafil (Viagra and generics), vardenafil and avanafil (Spedra), with legal status depending on the product (Viagra Connect 50 mg, for example, is a pharmacy medicine). The product on this page is an imported generic, and the pack shown on the listing is the manufacturer's own brand pack rather than a UK-licensed one. Its text, language and storage advice may differ from what UK users expect. It is worth bearing this in mind before you decide to use it, and equally worth keeping the original pack and leaflet for your prescriber to look at.

A single strength is offered, 100 mg, in packs of 4, 8, 16, 24, 32, 64 or 92 tablets. This page gives no dosing schedule, because UK guidance does not exist for udenafil. Take only what your prescriber has advised, and do not combine it with any other erectile dysfunction medicine.

PDE5 inhibitors as a class must never be taken with nitrates, whether tablets, sprays, patches or the recreational poppers (amyl nitrite), or with nitric oxide donors, because blood pressure can fall dangerously. They are also generally not advised after a recent heart attack or stroke, with unstable angina, severe heart failure, very low blood pressure, or severe liver disease, or if you have lost vision in one eye through optic nerve damage. Your doctor should also know if you take alpha-blockers, other blood pressure medicines, HIV protease inhibitors, or certain antifungals and antibiotics, which can raise PDE5 inhibitor levels.

The effects reported most often with udenafil are facial flushing and headache. Others include a blocked nose, red eyes, indigestion and dizziness, which fits the pattern seen across the group. An erection lasting four hours or longer is an emergency: go to A&E at once. Sudden loss of vision or hearing, chest pain during sexual activity, or fainting also need immediate help, and the tablets should be stopped. Do not drive or use machinery if you feel dizzy or your vision seems odd. Tell your GP about any side effect that lingers, since udenafil data are limited and unusual reactions matter.

Erectile difficulties can be an early sign of heart disease, diabetes, low testosterone or a side effect of other medicines, so it is wise to talk to your GP rather than self-treat. Your GP can offer a licensed alternative with full UK safety information, or advise whether an imported product such as udenafil is appropriate in your case.