Tasers, which are being introduced into New Zealand and Australian police forces as an alternative to firearms, paralyse a person by delivering electrical pulses through metal barbs shot from a gun.
A New Zealand emergency medicine doctor led a review of 86 international medical studies on Tasers, dealing with heart and respiratory problems, drugs, alcohol, pregnancy and trauma.
The article is published in the journal of the Australasian College for Emergency Medicine, highlights several cases:
* A psychiatric patient who removed the barb from his skin and swallowed it.
* A pregnant woman who miscarried after a barb lodged in her abdomen.
* A 16-year-old boy whose skull was penetrated by the dart.
* A man whose lung was punctured after being shot in the chest.
* Two police officers who suffered compression fractures in their spines from muscle spasms.
* A man who developed a twisted testicle.
Australian police were criticised last week when glue-sniffer Ronald Mitchell, 36, caught fire and suffered third-degree burns to 10 per cent of his body when he was Tasered.
A 2006 study by Amnesty International found Tasers were implicated in more than 150 deaths.
The doctor and her colleagues found that, despite Tasers being used extensively for decades, there was limited research into their implications for those most likely to be shot, such as the mentally ill, those under the influence of drugs and violent offenders.
"The Taser is not likely to be used on normal, healthy resting adults, where much of the research has been performed."
Emergency departments could expect to see more patients who had been Tasered, and it was important for doctors to be aware of those at higher risk of complications the doctor said.
More than 60 per cent of cases requiring the use of force involve people believed to be affected by alcohol or drugs and 13 per cent involved people having "some kind of mental health crisis".