Emergency Contraception

I had a reader ask for some basic resources on emergency contraception. Specifically information supporting the argument for using Plan B (a more expensive medication) over Ovral or other combined oral contraceptive pills (which cost pennies). The reader mentioned that from a sustainability perspective, doesn't it make sense to go with the cheaper medication?
While I understand the logic, there are several reasons why using a more expensive medication is the right thing to do. First off, the research documents a higher rate of efficacy when patients use progestin-only (Plan B) EC vs. combined oral contraceptives. You can read an excellent overview of EC from ACOG here (email me if you need the full-text article).
Secondly, there are fewer side effects for patients taking progestin-only pills. While we still keep anti-emetics available for patients who need them in our program, the research demonstrates a significant decrease in nausea and vomiting with progestin-only pills like Plan B.
Thirdly, Plan B can now be given as a single dose of 2 pills, rather than dosing 12 hours apart. A terrific boon for patient compliance. Although the packaging still says to give the 2 pills 12 hours apart, there is ample research that it's safe and effective to dose all at once. You can read more about dosing here and follow the links to existing independent research supporting the change in dosing.
To read more about emergency contraception laws across the US, check out the National Conference of State Legislator's site. Also, check out Preventing Pregnancy from Sexual Assault: Four Action Strategies to Improve Hospital Policies on Provision of Emergency Contraception.