Mefloquine one. Plasma concentrations of the (–)-enantiomer are significantly higher than those for the (+)-enantiomer, and the pharmacokinetics between the two enantiomers are significantly different. The (+)-enantiomer has a shorter half-life than the (–)-enantiomer. According to some research, the (+)-enantiomer is more effective in treating malaria, and the (–)-enantiomer specifically binds to adenosine receptors in the central nervous system, which may explain some of its psychotropic effects. Mefloquine was formulated at Walter Reed Army Institute of Research (WRAIR) in the 1970s shortly after the end of the Vietnam war. Mefloquine was number 142,490 of a total of 250,000 antimalarial compounds screened
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