Cannabis can help treat patients addicted to opiates and help with their withdrawal symptoms. There are no cannabis receptors in the brain areas involved with respiration, unlike the many receptors for morphine in those areas. Intentionally or accidentally taking too many opiates can cause overdose and death. On the other hand there is no risk of overdosing from taking too much cannabis for treatment of pain and, in fact, there have been no documented overdoses from cannabis, ever.