Hi efficientwanderer,
Lariam (mefloquine)
does not increase the risk of DCI. What it can do is produce signs and symptoms that may mimic and be confused with DCI. You might find the following article from my "Ask RSD" column in a past issue of "Rodale's Scuba Diving" to be informative (*see below).
That aside, Lariam has a very long half-life and adverse reactions may occur or persist up to several weeks after the last dose. While it cannot be said for certain, given a diver who had no problematic side effects a wait of at least two full weeks following the last dose would appear prudent. If worrisome side effects did or continue to occur, a wait of at least two full weeks following discontinuance of the drug
and complete disappearance of the adverse reaction would seem wise.
This is educational only and does not constitute or imply a doctor-patient relationship. It is not medical advice to you or any other individual and should not be construed as such.
Helpful?
Regards,
DocVikingo
* "Lariam (mefloquine) is a very effective drug in preventing and treating malaria, but can give rise to unwanted side effects, including vivid and disquieting dreams, hallucinations, anxiety, depression, confusion and forgetfulness. The US package insert directs that "...caution should be exercised with regard to driving, piloting an airplane, and operating machinery as dizziness, a disturbed sense of balance, neurological or psychiatric reaction have been reported during and following the use of Lariam," and states that "dizziness, sensory & motor abnormalities, headache and fatigue have been recorded in patient's taking the drug." These cautions are consistent with suggestions by some in the medical and dive communities that mefloquine may produce side effects which mimic DCS. Interestingly, the German package insert adds it should not be used for "certain activities which have a need for full attention and undisturbed motor activity," with a specific direction that pilots should not use Lariam for the prevention of malaria during their work.
Of most concern to the diver are the positions of some medical professionals that the drug simply should not be taken for malaria prophylaxis by those who are actively diving. These sources include Rodale's Diving Doc," Dr. Samuel Shelanski, and the German Society for Tropical Diseases. This later group, whose policies can be used as a basis for professional and legal action in cases of harm resulting from a physician's failure to follow them, states that people with a special need for three-dimensional orientation, for example pilots, scuba divers and others, should not take mefloquine as prophylaxis. Similar advice regarding scuba diving is provided by Dr Bridget Farham, B.Sc (hons), Ph.D, MB.ChB., an expert on tropical medicines, and appears in the package insert accompanying mefloquine dispensed in South Africa.
The above information suggests it would be prudent to take this drug only after detailed discussion with a physician who is fully aware of its current status, and to closely monitor for any adverse reaction."
The FDA has come out with the following warning regarding mefloquine:
http://www.fda.gov/bbs/topics/NEWS/2003/NEW00921.html
