How far apart should alcohol and birthcontrol be taken apart (ex. hours). also will this help reduce vomiting if taken further apart?

Doesn't matter.: Alcohol does not decrease the effectiveness of oral contraceptives. However, OCP's may reduce your liver's ability to clear alcohol from your system, resulting in higher alcohol levels from drinking. Your question seems to imply that your OCP's are causing vomiting. If so, you may need to be on a different one--The pill should not cause you to vomit. See your doctor. Good luck.