New psychoactive substances (NPS) explained: bath salts, herbal highs and health risks

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You may have heard the terms bath salts, legal highs, herbal highs, party pills, social tonics, research chemicals, or synthetic drugs.

They are some of the alternative names given to new psychoactive substances, or NPS.

What are NPS?

NPS are defined by the United Nations Office on Drugs and Crime (UNODC) as ‘new (and emerging) psychoactive substances where most are not controlled by international drug conventions, but which may pose a public health threat.’

They are drugs designed to mimic the effects of existing chemicals that are banned or regulated such as cannabis, cocaine, MDMA (ecstasy) and LSD.

While they may have similar effects to the psychoactive drug they mimic, they will often not be detected in the usual tests for that drug. For many, no test has yet been developed.

These factors can make them attractive to manufacturers, traffickers and users of illicit drugs.

But they also make them potentially dangerous.

New NPS emerge all the time as manufacturers try and stay ahead of the law. They are sometimes advertised as ‘legal’. They do not come with recommended dosage information, and packaging is often misleading about ingredients. Even if the packaging is the same, the product can be very different from batch to batch.

Because they are new, they are untested and unregulated, so there is often no safety data on toxicity or cancer-causing potential, and the adverse effects and risks are mostly unknown.

There have been recent reports of dangerous synthetic opioids or substances containing them circulating at festivals in Australia.

Health problems

NPS use has been linked to dozens of deaths and health problems including:

  • psychiatric problems
  • aggression and acute psychosis
  • memory and cognitive impairment
  • breathing difficulties
  • fatigue
  • headaches
  • cardiovascular problems
  • abnormally fast heartbeat (tachycardia)
  • nausea and persistent vomiting
  • seizures
  • tolerance and dependence.

Types of NPS

NPS are grouped into several main types:

  • Synthetic cannabinoids – designed to produce similar effects to cannabis.
  • Phenethylamines – a class of drugs with psychoactive and stimulant effects. It includes amphetamine, methamphetamine and MDMA (ecstasy). NPS phenethylamines include the ‘2C series’, the NBOMe series, PMMA, and benzodifurans.
  • Synthetic cathinones – related to the khat plant, they are stimulants that have an amphetamine-like effect. They include mephedrone (‘meow meow’) and methylone.
  • Phencylidine-type substances – similar to PCP (phencyclidine) and ketamine. They can be both dissociative and stimulating.
  • Tryptamines – psychoactive hallucinogens (psychedelics) that can affect all senses and produce hallucinations. They are found in plants, fungi and animals. Psilocybin is a tryptamine.
  • Piperazines – these are often sold as MDMA (ecstasy) for their stimulant properties.
  • Novel benzodiazepines – have sedative and hypnotic effects, varying dosages of active ingredients and contain contaminants, including highly potent synthetic opioids (UNODC 2022). (These often don’t fit into a precise category and are grouped as ‘other substances.’)

Reducing harm

The use of any drug can have risks. There were at least 82 deaths in Australia between 2007 and 2017 related to NPS use.

  • If someone is experiencing negative effects of any drug, including NPS, and look like they are in trouble, call Triple Zero (000) immediately and ask for an ambulance. Remember, ambulance officers don’t have to involve police.
  • Don’t combine drugs, including NPS, with other drugs or alcohol. This makes negative side-effects and the possibility of overdose more likely.
  • Many NPS contain fillers and cutting agents which can cause health problems.
  • NPS often contain high doses of caffeine, so additional caffeine from coffee or elsewhere can lead to overdose.
  • Don’t rely on the information on the packaging of NPS drugs as it often doesn’t list all the ingredients and can be misleading. Having said that, if you need to get medical help for yourself or someone else who is in trouble after taking an NPS, the package may be helpful for the clinicians to know how to treat the issue.
  • People with mental health conditions may be at higher risk of harm from NPS, and most of the deaths associated with them have involved people with mental health conditions.
  • Don’t drive, ride, swim, or operate machinery if you are under the influence of any drug.

Getting help

You can call the confidential alcohol and drug support service at any time, Adis 24/7 Alcohol and Drug Support.

Visit the website for an online chat or to register for the SMS support program or phone 1800 177 833 for free and confidential counselling, 24 hours a day 7 days a week.

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