It's not always that the release of a drug is celebrated by many, particularly men. A drug that was released in India last week is the recent in the list of drugs that has a cure for erectile dysfunction. The manufacturers say udenafil, which will be marketed under the brand name Udezire, will be long-acting, but with minimal side effects.

Erectile dysfunction (ED) is an inability to achieve or sustain an erection suitable for sexual intercourse. Sexologists say at least 10% men in India may have to use these drugs at some point. Studies have shown that 40% of men up to the age of 40 years have ED and it goes up 70% by 60 years.

The commonly prescribed drugs for the disorder in India are sildenafil (Viagra) and tadalafil, which belong to a category called phosphodiesterase type 5 drugs. Now, Zydus, a pharmaceutical company, has got exclusive permission to sell udenafil. The drug is manufactured by Korea-based Donga-A pharmTech Co. Ltd., and is being used in a dozen countries.

The last drug for the disorder was introduced nearly five years ago in the market. "Most of the existing drugs have side effects. While sildenafil puts pressure on the user to complete intercourse within four hours, tadalafil that lasts for nearly 17 hours causes back pain and headache in some users. Manufacturers say the effect of the new drug will last up to 12 hours, without much side effects," said sexologist Dr D Narayana Reddy.

Male sexual arousal is a complex process that involves the brain, hormones, emotions, nerves, muscles and blood vessels. Problems in any of these can cause erectile dysfunction. Stress and mental health problems can also cause erectile dysfunction. "In some people it could be a combination of physical and psychological issues," says Dr Reddy.

Manufacturers say they will market the drug through senior psychiatrists, andrologists, sexologists and diabetologists. In 80% of erectile dysfunction cases, physical factors such as drugs, blood flow abnormalities, nerve impulse abnormalities or hormonal abnormalities are the causes. Patients with high blood pressure and diabetes are also at risk of having erectile dysfunction. Physical causes of erectile dysfunction include heart disease, clogged blood vessels, high cholesterol, high blood pressure, diabetes, obesity, alcoholism, smoking, Parkinson's disease and other medical condition. Psychological causes of erectile dysfunction include depression, anxiety, stress or relationship problems.

The new drug will be priced at 575 per tablet, a little lesser than Viagra. "We expect to have 20% of the market share in one year because our survey reveals there is a fatigue with old drugs," said Zydus Pharma senior vice-president O P Singh.