Although, fortunately up to now, I never seem to have had many health problems with using opiates.

An additional 20 percent had used opiates like morphine or codeine.

"If you're so sick that you're using opiates or any controlled substance to control pain, you really need to stay home," Cummins says.

"People have been using opiates for centuries," he tells his wife.

A month later, she said she still hadn't gone back to using opiates.

The study indicated that between 2000 and 2009, the number of mothers using opiates increased from 1.19 to 5.63 per 1,000 hospital births per year.

There are a further 300,000 people regularly using heroin, crack cocaine or other opiates who are officially described as "problem drug users".

Methadone works on parts of the brain and spinal cord to block the "high" caused by using opiates (such as heroin).

There she killed five elderly patients using sedatives and opiates.

If someone uses opiates again and again, his or her brain is likely to become dependent on them.