These Dangerous Rx Meds Are Banned in the U.S. — and Here's Why Quaalude. Quaaludes were heavily misused. Meridia. This drug can increase your risk of heart attack and stroke. Zimelidine. Suicidal thoughts can increase while on this drug. Temafloxacin. This drug caused severe allergic reactions. Manoplax. This drug's effects only lasted three months. Trovan. Raptiva.