Why do you lay a person who has been poisoned on their right side as opposed to their left

Why do you lay a person who has been poisoned on their right side…?

http://www.chacha.com/question/why-do-you-lay-a-person-who-has-been-poisoned-on-their-right-side-as-opposed-to-their-left

Poisoning victims can be laid down on either side to prevent aspiration from vomiting. Pregnant females should be on left side.