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SUMMARY
Malaria is caused by infection with one of four different species of
parasite:
- Plasmodium falciparum
- P vivax
- P malariae
- P ovale
Although
it is thought of
primarily as a tropical disease, in the UK some 1,500–2,000 people
develop malaria each year and between five and 16 deaths occur.
Most
cases are in settled immigrants who contract malaria while visiting their
native country because they failed to take prophylaxis, took the wrong
prophylactic drugs or did not take prophylactics as instructed.
P falciparum is responsible for most of the deaths from malaria.
The other three parasites cause “benign” malarias, which
are rarely fatal, although symptoms can be severe.
Pharmacists can play
a
vital role in the A, B, C, D of malaria advice. They can: • Raise awareness of the risk of malaria in areas to be visited
• Communicate the importance of mosquito bite prevention
• Advise on chemoprophylaxis
• Assist prompt diagnosis
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Advice pharmacists can
give to travellers
• Take antimalarial drugs exactly as prescribed
• Always use insect repellents on exposed skin (the concentration
of DEET should be 20 per cent or more)
• Cover up when outside in the evenings and at night
• Sleep in a screened, air conditioned room or under an insecticide
treated mosquito net
• Kill any mosquitoes in the room before sleeping
• Seek medical advice if you develop side effects to prophylactic
antimalarials or develop a fever seven or more days after entering
an area where malaria occurs or up to one year after returning
to the UK (especially within the first three months) |
Treatment of malaria
Since the signs and symptoms of malaria are non-specific
it cannot be definitively diagnosed until parasites are detected
in a stained
blood film or by a dipstick test (rapid diagnostic test).
However,
it is essential to start treatment immediately because death
can occur if therapy is delayed. The drugs used will depend
on the species of parasite and its level of drug resistance, the
severity of the illness and patient factors. If the type of
malaria
is unknown, the regimen for P falciparum should be
prescribed.
For non-falciparum malaria, a three-day course of oral chloroquine
is used for P malariae, P ovale and P vivax.
For chloroquine-resistant strains of vivax malaria, quinine; artemether
with lumefantrine
(co-artemether); or atovaquone with proguanil can be used.
Primaquine is used to eradicate
dormant forms of P vivax and P ovale infections
and thus prevent relapse.
For uncomplicated falciparum malaria three suggested oral regimens
are:
• Oral quinine sulphate (for five to seven days) plus doxycycline
for seven days
• Atovaquone with proguanil for three days
• Artemether with lumefantrine for 60 hours The quinine-containing regimen has the disadvantage of being longer
and poorly tolerated. Adverse effects include nausea, deafness
and tinnitus.
Uncomplicated malaria can progress to severe malaria (ie, with
vital organ disturbance) or complicated malaria (ie, with potentially
fatal complications such as coma, severe anaemia, renal failure,
respiratory distress syndrome, hypoglycaemia, shock, spontaneous
haemorrhage and convulsions).
For severe or complicated falciparum malaria intravenous quinine
is the first-line treatment. Loading doses are required to achieve
high blood levels to eradicate parasites. Parenteral therapy is
given until the patient is well enough to take tablets.
Quinine
is given for five to seven days, together with or followed by
doxycycline for seven days. Clindamycin can be used for children and pregnant
women (unlicensed indication).
Patients with severe or complicated
malaria may need antipyretics, blood transfusions, dextrose
infusions, broad spectrum antibiotics (to treat infections, such as septicaemia),
support in respiratory failure or renal replacement therapy.
Patients
are usually treated in intensive care. |
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The
Pharmaceutical Journal