Advise patients that antimalarial drugs are
most effective if taken exactly on schedule without skipping
doses and that their drug should be continued post-travel
for the most complete protection. Antimalarial drugs should
be purchased before travel; drugs purchased overseas may not
be manufactured according to United States standards and may
not be effective. They may also be dangerous, contain the
wrong drug or an incorrect amount of active drug, or be combinations
of drugs that are not safe to use.
Halofantrine (marketed as Halfan) is widely used overseas
to treat malaria. CDC does not recommend the use of Halfan
because of serious cardiac complications, including deaths.
Travelers should be advised to avoid Halfan unless they have
been diagnosed with life-threatening malaria and no other
options are immediately available.
Overdosage of antimalarial drugs can be fatal. Parents should
be advised to keep drugs in childproof containers out of the
reach of children.
Travel to areas with Chloroquine-resistant P.
falciparum
Atovaquone/proguanil (Malarone)
Atovaquone/ proguanil is a fixed combination of two drugs;
in the United States , it is marketed as Malarone. Atovaquone/proguanil
primary prophylaxis should begin 1-2 days before travel to
malarious areas and should be taken daily, at the same time
each day, while in the malarious area, and daily for 7 days
after leaving such areas.
Doxycycline (brand names and generic drugs)
Doxycycline primary prophylaxis should begin 1-2 days before
travel to malarious areas. It should be continued once a day,
at the same time each day, during travel in malarious areas,
and daily for 4 weeks after the travelers leaves such areas.
Note: There are insufficient data on the antimalarial efficacy
of related compounds such as minocycline; optimally, for patients
already on minocycline, it should be discontinued prior to
travel and doxycycline started. Minocycline can be restarted
after the four weeks of post-exposure doxycycline is completed.
Mefloquine (Lariam and generic)
Mefloquine primary prophylaxis should begin 1-2 weeks before
travel to malarious areas. It should be continued once a week,
on the same day each week, during travel to malarious areas,
and for 4 weeks after the traveler leaves such areas.
Primaquine (primary prophylaxis)
If other antimalarial drugs cannot be used and in
consultation with malaria experts (CDC Malaria Hotline 770-488-7788),
primaquine may be used to prevent malaria while the
traveler is in the malaria-risk area (primary prophylaxis).
Note: Travelers must be tested for G6PD deficiency (glucose-6-phosphate-dehydrogenase)
and have a documented G6PD level in the normal range before
primaquine use.
Primaquine primary prophylaxis should begin 1-2 days before
travel to the malaria-risk area. It should be continued once
a day, at the same time each day, while in the malaria-risk
area, and daily for 7 days after leaving the malaria-risk
area.
Travel to Areas with mefloquine-resistant P.
falciparum
Mefloquine-resistant P. falciparum is present in
eastern Burma (states of Shah, Kayin, and Kayah), the western
provinces of Cambodia that border Thailand , and the provinces
of Thailand that border Burma and Cambodia .
Either atovaquone/proguanil or doxycycline can be used by
travelers to these areas.
Travel to areas with chloroquine-sensitive P.
falciparum
Chloroquine (Aralen, Plaquenil, and generic)
In areas where chloroquine-resistant P. falciparum has
not been reported, either chloroquine phosphate (Aralen and
generic) or hydroxychloroquine sulfate (Plaquenil) may be
used. Less evidence exists on hydroxychloroquine sulfate's
effectiveness as an antimalarial drug.
Chloroquine primary prophylaxis should begin 1-2 weeks before
travel to malarious areas. It should be continued once a week,
on the same day of the week, during travel to malarious areas
and for 4 weeks after a traveler leaves such areas.
Travelers unable to take chloroquine should take atovaquone/proguanil,
doxycycline, mefloquine, or primaquine; these drugs are also
effective against chloroquine-sensitive P. falciparum.
Adverse Reactions and Contraindications
The drugs used for antimalarial prophylaxis are generally
well tolerated. However, side effects can occur. Minor side
effects usually do not require stopping the drug. Travelers
with serious side effects should be advised to see their health
care provider.
Atovaquone/proguanil
The most common adverse effects reported in persons using
atovaquone/proguanil for prophylaxis are abdominal pain, nausea,
vomiting, and headache. Atovaquone/proguanil should not
be used in infants <11kg, pregnant women, women
breast-feeding infants <11kg, or patients with severe renal
impairment (creatinine clearance <30mL/min).
Chloroquine phosphate and Hydroxychloroquine sulfate
Side effects that can occur include gastrointestinal disturbance,
headache, dizziness, blurred vision, insomnia, and pruritus,
but generally these effects do not require that the drug be
discontinued. High doses of chloroquine, such as those used
to treat rheumatoid arthritis, have been associated with retinopathy;
this serious side effect appears to be extremely unlikely
when chloroquine is used for routine weekly malaria prophylaxis.
Chloroquine and related compounds may exacerbate psoriasis.
Doxycycline
Doxycycline can cause sun sensitivity, usually manifested
as an exaggerated sunburn reaction. Travelers on doxycycline
should be advised to protect themselves by avoiding prolonged
sun exposure and by using sunscreen that absorbs long-wave
UVA radiation.
Doxycycline use may be associated with an increased frequency
of Candida vaginitis. Travelers should be advised
to take an over-the-counter yeast medication or a prescription
drug or cream.
Gastrointestinal side effects (nausea or vomiting) may be
minimized by taking the drug with a meal and a full glass
of water. Travelers should be advised not to take doxycycline
before going to bed to avoid esophagitis.
Doxycycline should not be taken by persons
allergic to tetracyclines, pregnant women, and by children
<8 years of age.
Mefloquine
Mefloquine has been associated with rare serious adverse
reactions (including psychoses or seizures) at prophylactic
doses; these reactions are more frequent with the higher doses
used for treatment. Other side effects that occur with prophylactic
doses include gastrointestinal disturbance, headache, insomnia,
abnormal dreams, visual disturbances, depression, anxiety
disorder, and dizziness.
Mefloquine is contraindicated for use by travelers with a
known hypersensitivity to mefloquine and in persons with active
depression or a history of depression, or in persons with
generalized anxiety disorder, psychosis, schizophrenia, or
other psychiatric disturbances. Mefloquine is contraindicated
in persons with a history of seizures (not including the type
of seizure caused by high fever in childhood). Mefloquine
is not recommended for persons with cardiac conduction abnormalities.
Primaquine
Primaquine can cause hemolysis in G6PD-deficient persons,
which can be fatal. Before primaquine is used, G6PD
deficiency MUST be ruled out by appropriate laboratory testing.
Changing Medications During Chemoprophylaxis as a
Result of Side Effects
Antimalarial drugs have different modes of action
that affect the parasite at different stages of the life cycle.
If medications need to be changed because of side effects,
there are some special considerations. Travelers who start
mefloquine or doxycycline but must switch to atovaquone/proguanil
during or after travel must continue their atovaquone/proguanil
for 4 weeks after switching or 1 week after returning, whichever
is longer .
Assistance with the management of travelers who need to discontinue
their antimalarial drug and switch to another is available
at the CDC Malaria Hotline (770-488-7788).
Lactation
Very small amounts of chloroquine and mefloquine
are excreted in breast milk; the amount of drug is not sufficient
to harm the infant nor is the quantity sufficient to protect
the child from malaria. Breastfeeding infants should receive
the recommended dosages of antimalarial drugs found in the
table above.
Very limited data is available on the use of doxycycline
in lactating women; most experts consider the theoretical
possibility of adverse events to be remote.
Primaquine should only be given to lactating women if both
the woman and her infant have been tested for G6PD
deficiency and have documented normal G6PD levels.
Because safety data is not yet available, atovaquone/proguanil
is not currently recommended for women breastfeeding infants
<11kg.
Educate Your Patients on the Signs and Symptoms
of Malaria
Presumptive self-treatment regimen
| Drug |
Pediatric dose |
Comments |
| Atovaquone/proguanil (Malarone). Self-treatment drug
to be used if professional medical care is not available
within 24 hours. Medical care should be sought immediately
after treatment. |
Daily dose to be taken for 3 consecutive days using
** adult-strength tablets:
11-20 kg: 1 tablet
21-30 kg: 2 tablets
31-40kg: 3 tablets
> 41kg: 4 tablets
**Adult strength tablets contain 250mg atovaquone plus
100mg proguanil hydrochloride. |
Contraindicated in persons with severe renal impairment
(creatinine clearance <30mL/min). Not recommended for
self-treatment in persons on atovaquone/proguanil prophylaxis.
Not currently recommended for children <11kg, pregnant
women, and women breastfeeding infants <11kg. |
Advise your patients that they can still contract malaria
despite prophylaxis and anti-mosquito measures. Inform travelers
that fever or flu-like illness, either while traveling or
after returning home (for up to 1 year or more), may be malaria
and that they should seek immediate medical
attention.
Self-Treatment
Malaria can be effectively treated early in the course of
the disease; however, delay of appropriate treatment can have
serious or even fatal consequences. Travelers who choose not
to take an antimalarial drug or who are on a less than effective
regimen (chloroquine in a chloroquine-resistant risk area)
or who may be in very remote areas can be given a self-treatment
course of atovaquone/proguanil.
Travelers on atovaquone/proguanil as their antimalarial drug
regimen should not use atovaquone/proguanil as their self-treatment
drug and should use an alternative self-treatment regimen;
call the Malaria Hotline (770-488-7788) for advice on the
management of travelers who cannot use atovaquone/proguanil
for self-treatment.
Prevention of Mosquito Bites
Malaria is transmitted by the bite of an infected Anopheles
mosquito; these mosquitoes usually bite between dusk
and dawn. Advise your patients to remain indoors, if possible,
in a screened or air-conditioned area during the peak biting
period. If out-of-doors, travelers should be advised to wear
long-sleeved shirts, long pants, and hats and to apply insect
repellent to exposed skin. Insect repellents that contain
DEET (diethylmethyltoluamide) are the most effective repellents
against a wide range of vectors.
Advise your patients to follow these precautions:
- Read and follow the directions and precautions on the
product label.
- Use only when outdoors and wash skin with soap and water
after coming indoors.
- Do not breathe in, swallow, or get into the eyes. (DEET
is toxic if swallowed). If using a spray product, apply
DEET to your face by spraying your hands and rubbing the
product carefully over the face, avoiding eyes and mouth.
- Do not put repellent on wounds or broken skin.
- Higher concentrations of DEET may have a longer repellent
effect; however, concentrations over 50% provide no added
protection.
- Timed-release DEET products may have a longer repellent
effect than liquid products.
- DEET may be used on adults, children, and infants older
than 2 months of age. Protect infants by using a carrier
draped with mosquito netting with an elastic edge for a
tight fit.
- Children under 10 years old should not apply insect repellent
themselves. Do not apply to young children's hands or around
eyes and mouth.
- Pregnant women should use insect repellents containing
DEET, as recommended for other adults, but use sparingly.
Wash off with soap and water after coming indoors.
Travelers should also take a flying-insect spray on their trip to help clear rooms of mosquitoes. The
product should contain a pyrethroid insecticide;
these insecticides quickly kill flying insects, including
mosquitoes.
Travelers not staying in well-screened or air-conditioned
rooms should take additional precautions, including sleeping
under mosquito netting (bed nets). Bed nets sprayed with the
insecticide permethrin are more effective; permethrin
both repels and kills mosquitoes. In the United States , permethrin
is available as a spray or liquid (e.g. Permanone) to treat
clothes and bed nets. Overseas, bed nets may be purchased
that have already been treated with permethrin.
Permethrin or another insecticide, deltamethrin ,
may be purchased overseas to treat bed nets and clothes.
For additional information on malaria risk and prevention,
please see the following:
*Use of trade names is for identification
purposes only and does not imply endorsement by the Public
Health Service or by the U.S. Department of Health and Human
Services.
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