VIENNA, Austria - Governments around the world must step up their efforts to limit access to date-rape drugs, sedatives that are secretly added to a person's drink to reduce their ability to resist sexual assault and remember it later, a watchdog said Wednesday.

Sexual predators can easily procure such drugs despite existing efforts to curb their misuse, the International Narcotics Control Board said in its annual report.

Governments should quickly adopt measures to limit illegal access to such drugs, and increase public awareness about the risks of leaving food and drinks unattended at public events such as parties, the board said. They also must do a better job of analyzing urine samples in suspected cases and be consistent about compiling and sharing statistics.

"The date-rape drug phenomenon, although fairly new, is evolving rapidly as sexual abusers attempt to circumvent stricter drug controls by using substances not restricted by international drug conventions," the Vienna-based UN agency said in a statement accompanying the report.

The misuse of flunitrazepam -- sold under the brand name Rohypnol -- has been reduced, thanks to international efforts, but the report said criminals are now using gamma-Hydroxybutyric acid -- known as GHB -- or ketamine and gamma-Butyrolactone, commonly referred to as GBL.

"Since in many countries most of those drugs are easily available, they frequently fall into criminal hands," the board said.

While GHB was put under international control in 2001, not all countries have followed up with regulations on a national level, the report said. Ketamine and GBL, meanwhile, remain outside drug conventions and can therefore be easily obtained.

"Drug traffickers obtain the substances in question through Internet pharmacies and the mail system, or from illicit manufacture," the report said.

To tackle the problem, the board urged governments to work together with the pharmaceutical and chemical industries, and to ensure that police and prosecutors have the legal authority to take appropriate action against offenders or suspects.

"In many countries, the use of substances to facilitate the commission of crime does not constitute a criminal offence and therefore cannot be properly sanctioned," the report said.

The report also included these findings:

-- In many countries, prescription drugs are the second or third most abused category of drugs. In the U.S., 6.2 million people abused prescription drugs in 2008. That was more than the total number of people who abused cocaine, heroin, hallucinogens, ecstasy and inhalants. In Germany, an estimated 1.4 million to 1.9 million people are addicted. While almost all countries are confronted with prescription drug trafficking and abuse, there is still a significant lack of awareness and data about the problem.

-- Faced with tighter controls of chemicals needed to make some drugs, traffickers and underground manufacturers are successfully shifting gears. Since a comprehensive ban on ephedrine and pseudoephedrine took effect in Mexico, for example, traffickers are increasingly using phenylacetic acid to make methamphetamine.

-- In Central America and the Caribbean, drug traffickers are increasingly using light aircraft with stolen or falsified registration numbers to transport illegal substances. Drug trafficking by sea also remains a problem in the region.

-- The smuggling of cocaine through West Africa from South America into Europe and elsewhere continues to be a serious problem and is contributing to an increase in cocaine abuse in the region. The seizure in Guinea in July of large amounts of chemicals and equipment suspected of being used to make synthetic drugs shows the region also remains at risk of being used by traffickers for the diversion of chemicals.

-- Trafficking in amphetamine-type stimulants has increased in South Asia and the discovery of several methamphetamine laboratories in the region over the past two years shows that countries in the area are increasingly being used to produce stimulants. In India, courier and postal services have become a common means of smuggling drugs out of the country.

-- While Britain, Italy, France and Germany account for most of the heroin seized in Europe, Eastern Europe's underground market for opiates has continued to expand. Recent national surveys suggest that cannabis use is stabilizing in many countries in the region. However, in Denmark, Spain and Britain, drug abusers may be replacing amphetamines and ecstasy with cocaine.

-- The United States continues to be the world's largest market for illegal drugs. Cannabis remains the most commonly abused substance, followed by the misuse of prescription drugs.

-- Afghanistan remains by the far the largest illegal producer of heroin and other opiates and also is becoming a major producer of cannabis.