PFPC Daily - March 3, 2005

Lariam = Mefloquine

van Riemsdijk MM, Sturkenboom MC, Pepplinkhuizen L, Stricker BH -
"Mefloquine Increases the Risk of Serious Psychiatric Events During
Travel Abroad: A Nationwide Case-Control Study in the Netherlands" J
Clin Psychiatry 66(2):199-204 (2005)

BACKGROUND:

Psychiatric events during travel abroad account for a large
percentage of medical repatriations arranged by insurance companies.
Several risk factors have been proposed for such events, one of these
being use of mefloquine. We investigated the risk of psychiatric
events during use of mefloquine.

METHOD:

We performed a nationwide case control study using medical
records from 4 large alarm centers in the Netherlands. Cases were
patients contacting the alarm centers because of psychiatric events,
according to International Code Primary Care code P (all psychiatric
symptoms) or International Classification of Diseases, Ninth Edition,
codes 290-319 (all psychiatric syndromes). To every case we matched
up to 6 controls by alarm center, calendar time, and continent of
travel. All controls had contacted the alarm centers because of
nonpsychiatric medical reasons. Shortly after the anticipated day of
return, cases and controls received a questionnaire regarding travel
characteristics, gender, age, marital status, education, weight,
height, general health, history of psychiatric diseases, use of
medicines, smoking status, alcohol intake, coffee intake, and use of
malaria prophylaxis. Dates of travel for the source population were
between September 1, 1997, and June 1,2000.

RESULTS:

The study population consisted of 111 cases and 453 controls. The
risk of psychiatric events during the use of mefloquine was 3.5 (95%
CI = 1.4 to 8.7). In females, the risk was strongly increased, with
an odds ratio of 47.1 (95% CI = 3.8 to 578.6). Stratification for
history of psychiatric diseases showed that the risk of psychiatric
events during use of mefloquine in cases without a history of
psychiatric diseases was 3.8 (95% CI = 1.4 to 10.1), whereas the risk
in cases with a history of psychiatric diseases was 8.0 (95% CI = 1.8
to 35.8).

CONCLUSION:

The use of mefloquine is associated with an increased risk of
psychiatric events in females and in patients with a history
of psychiatric diseases.