A report published in The Medical Journal of Australia found people who didn't eat enough, drank a lot of alcohol or took certain medications were vulnerable to toxic effects from paracetamol.
Elderly people with kidney or heart and lung problems may also be at increased risk.
"Accidental paracetamol poisoning should be suspected in any patient with acute liver failure," the report said.
"Clinicians should be cautious about prescribing regular doses of paracetamol for pain control in malnourished or fasting patients, and need to counsel patients who are regular users of the drug."
Healthy people are usually able to metabolise paracetamol, most of which is excreted from the body in urine.
But the drug can accumulate in people with risk factors, rendering even a normal dose toxic.
