Canberra hospitals have seen an increasing number of overdoses linked to the drug GHB, medical experts say. Emergency doctors say a small trend of GHB use among Canberrans has emerged in the ACT in recent months. Calvary Hospital emergency doctor David Caldicott said while emergency rooms aren't being inundated at levels seen at the drug's peak in the early 2000s, smaller trends have emerged. "We've seen several GHB-like overdoses in the last year, so it's definitely around Canberra," Dr Caldicott said. "I've spoken with my colleagues that are southside and they've seen the same thing." Also known as liquid ecstasy or fantasy, GHB is a colourless and odourless liquid, mainly used as a party drug. The drug was most prominent during the late 1990s and early 2000s. Dr Caldicott said the illicit drugs market was cyclical, and though GHB hadn't disappeared entirely since its peak a decade earlier, it was still being used. "There was a generation of drug consumers in the 2000s who were put off by GHB and it's probably been rediscovered again, but [the drug] is nothing new," he said. "Within the trend of drug use, what we see are fads or surges. GHB is not going to be something to slip into the market or be mistaken for a pill." A Canberra Health Services spokeswoman said several patients had been seen in recent months in emergency rooms with symptoms consistent with toxicity from GHB. "The diagnosis is usually made based on the clinical history and physical examination, and management commences without confirmatory laboratory testing," the spokeswoman said. "GHB-related cases are concerning as the condition of these patients can change rapidly and they are at risk of severe complications." The resurgence of GHB comes as Canberra emergency staff have seen an increase in other stimulant drugs such as methamphetamine. "This group of drugs has caused a significant impact locally and nationally in regard to the number of presentations, unpredictable behaviour and risk of violence," the health services spokeswoman said. GHB has seen a resurgence of use overseas in the UK in past months. A British survey earlier this year of 2700 gay and bisexual men found half had passed out after taking the drug and one in four had been sexually assaulted after using it. Dr Caldicott said the UK had seen a rise in GHB cases more severely than other major Australian cities such as Sydney and Melbourne, where small spikes have been reported. He said the way the drug was consumed put users at a high risk of overdosing. "It can be a very difficult drug to dose properly and it's a fluid, so as with other drugs, it's hard to know what concentration it is or if it's diluted," Dr Caldicott said. "An overwhelming majority of consumers don't measure out a dosage, they'll just take a swig." As the summer party season approaches, Dr Caldicott said drug trends were being monitored, but said it was unlikely GHB would the drug of choice for partygoers. "We're on the highest alert [at that time of year]. Over the winter months we're looking overseas to see what drugs are being used and we're looking at patterns," he said. "There are issues with GHB as a drug that make it less attractive to those traditionally seeking drugs like MDMA, and I'd be very surprised if GHB became more popular than MDMA, but I'm still surprised [GHB] is still lingering."