Mefloquine the drug's very long half-life, the Centers for Disease Control originally recommended a mefloquine dosage of 250 mg every two weeks; however, this caused an unacceptably high malaria rate in the Peace Corps volunteers who participated in the approval study, so the drug regimen was switched to once a week. The first randomized, controlled trial on a mixed population was performed in 2001. Prophylaxis with mefloquine was compared to prophylaxis with atovaquone-proguanil. Roughly 67% of participants in the mefloquine arm reported greater than or equal to one adverse event, vs 71% in the atovaquone-proguanil arm. In the mefloquine arm, 5%
Alternative treatments used for the common cold children by 18%. Vitamin C also decreased the severity of colds. A systematic review by the Cochrane Collaboration, last updated in 2014, examines twenty-four randomized controlled trials studying various echinacea preparations for prevention and treatment of the common cold. Echinacea showed no benefit over placebo for prevention. Evidence for treatment was inconsistent. Reported side effects were rare. 2007 meta-analyses conclude that there is some evidence that echinacea may reduce either the duration or severity of the common cold, but results are not consistent. Use of echinacea preparations is not currently recommended. In the twelfth century, Moses Maimonides wrote, "Chicken soup