Re: Is it safe to take anti-malarials 365 days per year??

Malaria prophylaxis  was designed in order to prevent serious  
complications that  can lead  to death in  non-immune individuals in 
malaria caused by Plasmodium  falciparum.  Since no  effective  vaccine 
exists to  prevent  the  infection, it  was rationalized  that  
maintaining  high  blood  levels  of   drugs  that   kill  the  parasite  
will  stop  development  of  the   disease  in case  a  person   gets   
bitten   by  a  female   mosquito  carrying  infective   sporozoites. 
Decision  to  start  prophylaxis   depends on whether   a person   will  
be  going  to   a  P. falciparum   endemic  area  where   transmission  
occurs. Usually people  who  visit  large  cities   will not  be  at 
risk.  Which    drug or  drugs  are  to be  used  depends on the  length  
of  time  the individual  will  be  exposed   to malaria  transmission 
AND  on whether   the  parasite  is  sensitive  to   that  drug  or  
drug   combination. For  example,   cloroquine is one  of  the  drugs 
that  was initially  used and is  relatively  non-toxic at  the  dosages   
recommended for  malaria prophylaxis (although  retinal  damage  has  
been  reported  with prolonged  use  at high   dosage). However,  nowadays 
there  are  few  places  in the  world  where  P. falciparum is  not  
resistant  to   this   drug. So its use is  no longer  recommended  for  
prophylaxis.  Other  drugs  like   doxycyclin  or  mefloquine  are  much  
more   toxic  and  should  not  be  taken  for  more  than  3 consecutive  
months.  As  a matter of  fact, any  drug  taken continously for  long  
periods  of   time  (more than  six  months)  will   sooner or  later  
produce  secondary  effects. These  effects  depend  on the type  of  
drug  and   on the  individual. (see references). 

If the  decision  to  start  prophylaxis  is  taken  by  attending the  
medical  doctor, the  patient  must  realize that  the  protection  
offered  by  these  drugs  is  not  absolute  and despite  adequate  
dosage malaria   may  still   develop (although the  probability  is  
much   smaller). So the  patient  must  be aware of  any  signs  or   
symptoms  and  proceed immediately  to   have  appropiate  diagnosis.

In some  malaria  endemic  areas,  clinicians  prefer  not  to  prescribe 
prophylaxis to  occasional nonimmune travellers  because  they  feel  
this   can delay adequate  diagnosis  and  treatment. Instead , they  
prefer  to use  barrier  methods, i.e. methods  that  reduce  contact   
between  humans  and  mosquitoes. Among these are:
	
1) Sleep in screened areas. Spray properly screened room with insecticide 
before evening. Use pyrethrum-containing sprays and mosquito coils. 
Electronic buzzers are not effective.
2) Use mosquito netting and check for holes in the net.
3) Wear protective clothing. Long sleeved clothing and long trousers should 
be worn if out of doors after sunset. 30ml of DEET in 250ml water can be 
used to impregnate cotton garments.
4) DEET insect repellents may be applied to exposed skin. 
5) Alternately, use permethrin-containing pesticide for clothing and 
mosquito netting 0.2g/m2 of material every 6 months. 

Perhaps  the   most  important  messages  for non-immune  travellers  to   
malaria   endemic  area  are: a)  malaria  should   ALWAYS  be 
considered  in the  differential   diagnosis  if  the  patient  presents   
fever,  malaise   or  headache upon  return  to   the  home  country 
(regardless of  prophylaxis  and   barriers methods  use)  and  b) 
malaria  in a nonimmune  individual  is  a medical  emergency  and  must  
be  treated IMMEDIATELY. 

http://www.pol-it.org/malaria.htm 

http://
meds.queensu.ca/hsj/vol1-1/malproph.html
 http://
www.icp.ucl.ac.be/~opperd/parasites/malaria%20prophylaxis.html
 http://www.cdc.gov/travel/
malariadrugs2.htm
 http://www.21stcenturyadventures.com/articles/malaria.html