| Drugs Most Commonly Used for
Malaria Prevention are Chloroquine, Proguanil,
Mefloquine, Doxycycline and Malarone
Travelers must always, through discussion with their
doctor or pharmacist, make sure they use a prophylaxis
drug which they can tolerate (only the more common side
effects are given here and one which is appropriate for
their destinations). No drug is 100% effective.
Chloroquine
Preparations available: Avloclor® (Zeneca) and Nivaquine®
(Rhône-Poulenc Rorer). Adult dose is 2 tablets (each
containing 150mg chloroquine as base) taken once a week.
Nivaquine is available in syrup form.
Consider a trial course before departure, if using this
regime for the first time, to detect if you are likely to
get side effects (e.g. for two weeks). Otherwise, when
possible, chloroquine should be started one week before
exposure (to ensure adequate blood levels), throughout
exposure and for 4 weeks afterwards.
Nausea and sometimes diarrhea can occur which may be
reduced by taking tablets after food.
Headache, rashes, skin itch, disturbance of visual
accommodation (often expressed as blurred distance vision
which may take up to 4 weeks to reverse) or hair loss may
warrant changing to alternative drugs.
Retinopathy (eye changes) which can be permanent is
unlikely to occur until 100g have been consumed (i.e.
over 5 years treatment at prophylactic doses).
Caution in liver and renal disease.
Can aggravate psoriasis and very occasionally causes a
convulsion so it should not normally be used in those
with epilepsy.
Chloroquine is very toxic in overdose - parents must take
special care to store the tablets safely.
It is generally accepted, as a result of long usage, to
be safe in pregnancy.
Proguanil
Preparations available: Paludrine® (Zeneca. Adult dose is
200mg daily.
Can normally be used continuously for a period of up to 5
years.
One or two doses should be taken before departure. It
should be continued throughout exposure and for 4 weeks
afterwards.
Anorexia, nausea, diarrhea and aphthous (simple) mouth
ulcers can occur.
Can delay the metabolism of the anticoagulant, warfarin,
and result in bleeding. Those planning to take warfarin
must discuss this with their doctor before starting any
treatment.
Caution in renal impairment.
Considered to be safe in pregnancy, but folate supplement
is advised.
Mefloquine®
Preparations available: Lariam® (Roche). Adult dose is
250mg weekly.
One dose should be taken a week before departure and it
should be continued throughout exposure and for 4 weeks
afterwards however three (3) doses at weekly intervals
prior to departure are advised if the drug has not been
used before - this can often detect, in advance, those
likely to get side effects so that an alternative can be
prescribed.
Not licensed in Britain for use for more than 1 year (in
countries where it is licensed for more than 1 year,
additional side-effects are rare).
Nausea, diarrhea, dizziness, abdominal pain, rashes and
pruritis can occur.
Headache, dizziness, convulsions, sleep disturbances
(insomnia, vivid dreams) and psychotic reactions such as
depression have been reported. These reactions most
commonly begin within 2-3 weeks of starting the drug and
may be worse if alcohol is taken around the same time as
the mefloquine.
Avoid in epilepsy, if there is a close family history of
epilepsy (e.g. parents or siblings) or if there is a
history of psychiatric illness.
Caution, and avoid if alternatives are available, in
severe renal or liver failure and those with heart rhythm
defects. Also caution in those taking Digoxin, beta or
calcium channel blockers when arrhythmias and bradycardia
can occur.
Although there is no evidence to suggest that mefloquine
has caused harm to the fetus it should normally be
avoided during the first trimester of pregnancy or if
pregnancy is considered possible within 3 months of
stopping prophylaxis.
Doxycycline
Preparations available: Doxycycline (non-proprietary),
Vibramycin® (Invicta). Adult dose is 100mg daily.
Can normally be used continuously for a period of at
least 3 months - be guided by your doctor.
Consider a trial course before departure, if you are
using this regime for the first time, to detect if you
are likely to get side effects (e.g. for one week).
Otherwise doxycycline need only be started just before
exposure (e.g. 2 days), continued through exposure and
for 4 weeks afterwards.
When other tetracycline's are being already used for acne
this will provide protection against malaria so long as
an adequate dose is taken (you can change to 100mg
doxycycline per day if your doctor agrees).
Erythema (sunburn) due to sunlight sensitivity can occur.
Use of sunscreens is especially important and if severe,
alternative prophylaxis should be used.
Heartburn is common so the capsule should be taken with a
full glass of water and preferably while standing
upright.
Contraindicated in pregnancy (including one week after
completing the course), breast feeding, in those with
systemic lupus erythematosis, porphyria and children
under 12 years because permanent tooth discoloration can
occur.
It may reduce the effectiveness of the oral contraceptive
pill, you should discuss this with your family planning
advisor.
Occasionally anorexia, nausea, diarrhoea, candida
infection and sore tongue (glossitis) have been reported
and rarely hepatitis, colitis and blood dyscrasias.
Malarone®
Adult dose is one tablet daily - each tablet contains
250mg atovaquone plus 100mg proguanil. Not licensed in UK
for children less than 40kg.
DO NOT confuse with Maloprim® which is not now advised
for prophylaxis since more effective alternatives are
available.
Should be taken for 1 or 2 days before entering the
malarious area, throughout exposure, and for 7 days after
leaving the infected area. Can be used for trips of up to
28 days.
Consider a trial course before departure if you are using
this regime for the first time so as to detect if you are
likely to get side effects (e.g. one week). Otherwise
Malarone need only be commenced one or two days before
exposure.
Abdominal pain, headache, anorexia, nausea, diarrhea,
coughing and aphthous (simple) mouth ulcers can occur.
Absorption may be reduced in diarrhea and vomiting, and
blood levels are significantly reduced with concomitant
use of tetracycline's, metoclopramide and especially
rifampicin or rifabutin
The proguanil component can delay the metabolism of the
anticoagulant, warfarin, and result in bleeding. Those
planning to take warfarin must discuss this with their
doctor before starting any treatment.
Caution in renal impairment.
Lack of experience in pregnancy and during breast feeding
means that it should be avoided in these circumstances
unless there is no suitable alternative.
No guidance is given yet on long term use by the
manufacturers - the high cost makes it likely that it
will be mostly used for short trips.
source: Scottish NHS
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