[e-drug] Mefloquine as malaria chemoprophylaxis (4)

Mefloquine as malaria chemoprophylaxis (4)
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Dear E-druggers,

In response to Kae Ting Trouilloud's request regarding mefloquine as
malaria prophyaxis for a ship captain, I would prefer doxycycline as
prophylaxis in this situation. Accounts of mefloquine-related
side-effects, derived from travelling pages on the Internet as well as
from several personal communications (based on personal experience and
of individual travellers into Zambia, Namibia and Northeastern parts of
South Africa), confirm that psychotic side-effects of mefloquine are
real and common.

Doxycycline is currently widely accepted for prophylaxis of malaria and
has neither major documented effects on performance, nor other serious
side effects resulting from prophylactic doses. However, apart form
being an antibiotic that may contribute to resistance in microbes, it is
unsuitable for young children, and may cause nausea on an empty stomach.
As a pharmacologist, however, my only real concern in the long run
would be the relative lack of conclusive evidence (to my knowledge) of
the overall global effect on microbial resistance of widespread
doxycyline use against malaria - microbial resistance being an equally
serious global problem. Failing more effective and safer prophylaxis
against a killer disease such as malaria, I am currently content with
the use of doxycycline, taking the risk-versus-benefit analysis of the
matter into account.

Incidentally, can someone perhaps update us on changes in bacterial
resistance patterns associated with doxyxyline use since its use as
malaria prophylaxis started increasing? Has any notable doxycycline
resistance in malaria parasites been documented ? And for that matter,
against mefloquine?

Rina Meyer
Senior Lecturer (Pharmacology)
Northwest University (Potchefstroom Campus)
South Africa
FKLCLM@puknet.puk.ac.za

E-DRUG: Mefloquine as malaria chemoprophylaxis (5)
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In answer to Rina Meyer's question, there isn't really convincing evidence
that prophylactic use of any antimalarial contributes to plasmodial
resistance. Resistance is thought to derive from therapeutic drug pressure
in endemic areas.

The majority of travellers who develop clinical malaria while taking
prophylaxis will have departed the malarious area of exposure before patent
malaria develops. Additionally, transmission of resistant parasites only
becomes possible once gametocytaemia occurs. This is typically a late
development in non-immunes, and most would have presented for treatment
before gametocytaemia develops.

Dr Stephen Toovey MBBCh, CTM, FACTM, FFTM
Johannesburg South Africa, Basel Switzerland
Phones:+27-82-466-6322;+41-61-421-7872
SMS:+27-82-466-6322
Fax:+41-61-421-7063
Postal address: Burggartenstrasse 32, CH-4103 Bottmingen, Switzerland
toovey@travelclinic.co.za