AS WORCESTER's clubs and pubs ready themselves for wave of new students coming to the city, a warning is going out about the dangers of spiked drinks after recent troubling cases.

Several women were believed to have been targeted with spiked drinks in Essex earlier this week and West Mercia Police are investigating still a case where three young women were targeted on a night out in Worcester.

The women were taken to the accident and emergency department at Worcestershire Royal after the incident in April.

The number of investigations into alleged spiking, where victim's drinks are contaminated with a drug, likely with an aim to make them vulnerable targets of sexual assault, have more than doubled in the past year.

Similarly, in a study conducted by it found 44 per cent of men and 56per cent of women said they had had consumed spiked drinks or food.

The most common drugs being used include Rohypnol, Ketamine and Diazepam and the side effects include confusion, drowsiness, muscle spasms, unconsciousness and breathing difficulties. It can also cause seizures and the need for resuscitation,

Those found guilty of the crime can get up to a 10-year prison sentence.

The Worcester case came to light when one of the victim's friends sent out a warning via Facebook.

"We had all drank the same amount near enough, however one of my mates by about 10:30pm had started to be really sick and just looked genuinely so poorly slumped on the table," she said.

"She couldn’t lift her head. We had help to carry her outside as the staff weren’t willing to help us inside. She started to be really floppy and confused.

"Within an hour, our friend became completely unresponsive and 999 was called straight away.

"After this we checked on our two other friends that had left the club about 30-45 mins before us, with the same situation.

"Please girls out there, be careful."

According to Save the Student website, methods to avoid getting spiked include never leave your drink alone and always try and go to the bar with a friend.

Other suggestions include keeping you drink covered with either your hand, a cover or your phone.

It also urges people to never accept drinks from strangers, watch for changes in taste of your drink and don't drink from other people's glasses.