He says his organization is working with the World Health Organization on a project to curb the disease. The program focuses on Peru, where malaria cases have increased dramatically to about 200,000 annually for a number of reasons, including development of once remote areas. It also includes research for an effective preventive vaccine. I contacted Lynn Sorrells, a travel nurse at the Palo Alto Medical Foundation in California. I told her that I'd heard horror stories about mefloquine from fellow travelers, usually about a friend of a friend, and usually involving someone losing their marbles.
Some people feel kind of spacey on it.
Ann Barber at the Center for Disease Control in Atlanta says a study revealed no long-term problems. Some of them were on the drug for up to two and a half years. There were no serious long-term effects at all recorded. If you have minor side effects, such as nausea or feeling slightly out of it, they should go away. As with any drug, if you have a side effect so severe that you cannot function or it's ruining your trip, discontinue, see a doctor and have the drug changed.