Ice causes death in many ways, overdose is just one of them

Methamphetamine (usually colloquially referred to as “ice”) is a major public health problem in Australia. When we think of methamphetamine-related death, however, we tend to focus on overdose. This is a very real and valid concern. But the extent of the problem extends far beyond drug toxicity.

Methamphetamine dependence is associated with an array of serious social, mental and physical health problems that include heart disease, stroke, suicide, mood and anxiety disorders, psychosis, and violence. The footprint of methamphetamine is far wider than that of many other drugs. Close to half of deaths occur in rural and regional areas, a great many users are employed, and half have never injected a drug. These are not the “usual suspects” for drug-related death.

In a new study we looked at all of the methamphetamine-related deaths that occurred in Australia from 2009 to 2015. There were 1,649 such deaths over that period, and the annual rate doubled from around 150 a year to 300. Of these deaths, 43% were due to drug toxicity.

In the case of methamphetamine, overdose typically results in heart arrhythmias (where the heart isn’t beating properly) and seizures caused by the drug. Importantly, even modest amounts of methamphetamine may cause heart arrhythmia and death. The remainder, however, were due to other causes.

How methamphetamine affects the heart long-term

In a fifth of cases, death was due to methamphetamine combined with disease, most commonly heart disease. Methamphetamine is cardiotoxic, meaning it causes damage to our heart muscle, and causes disease in our arteries.

There’s a circular pattern here. Methamphetamine damages the cardiovascular system. The drug also places strain on this system by increasing the force of the blood against the artery walls (it’s a “hypertensive”). Users are then placing strain on damaged hearts. And this damage accumulates and does not reverse.

There’s also a real risk of stroke, and we saw 38 such cases among young people, a demographic not commonly affected by stroke. Importantly, the damage to the cardiovascular system occurs regardless of how the drug is used. Smoked, injected or swallowed – it is the drug that does the damage.

How methamphetamine fatally reduces inhibition

Methamphetamine is also associated with traumatic injury and death, as it causes a high degree of disinhibition, impulsivity, aggression and impaired critical judgement. There were 300 completed suicides related to methamphetamine over our study period.

There were around 300 deaths from suicide linked to methamphetamine, and the methods used were more violent, which is linked to the aggression, violence and aggravation caused by the drug.

Some 15% of all methamphetamine-related deaths were due to traumatic accidents, most commonly motor vehicle accidents. Methamphetamine users commonly believe the drug improves their driving. It does not. What it does improve is the risk of injury and death. All of these deaths were avoidable.

What can we do?

Knowledge of the risks is a start. Many users might assume a racing heart and chest pains are part of the experience of using methamphetamine and not realise these are signs of a system under stress. The heart disease we are seeing in methamphetamine users will be a problem for decades to come, long after they cease use.

In terms of our treatment system, drug treatment centres need to be aware their methamphetamine patients may be at risk of heart disease. Doctors also should ask about methamphetamine involvement if young people are presenting with heart conditions.

Over the past few years there has a been an intense focus on methamphetamine in the wake of evidence of increasing use and harms, including in rural and regional areas. By examining the causes of these deaths we have uncovered that, unlike many other drugs, the harms are very diverse, particularly with regard to the extensive association with heart disease.

This suggests that even if use goes down, we will have a major public health problem for our hospital and community health services for many years to come.

Another striking finding of this research is that very few of those who died were in treatment at the time. Our treatment services are already under intense pressure and this underlines the urgent need for more resources to go into treatment and trials of new medications.