http://www.qo2022.com/web/info-qatar-2022.html
In January 2010, The Supreme Council of Health banned the use and sale of Reductil Sibutramine (the anti-obesity pill). Medications including codeine, tranquilisers, some antidepressants and some sleeping pills are also banned.
Best to bring your perscription and/or a letter from your Dr for any prescription drugs that you might not be sure about. You won't be arrested though provided they aren't "social" drugs...at the worst they will be taken off you.