What are antimalarials?
Introduced during World War II as an antimalarial drug, chloroquine
(brand name - Aralen) was later followed by synthesis of the chemically-related
compound, hydroxychloroquine (Plaquenil). As early as the 1960's
it was noted that these medications produced a beneficial side effect.
With chronic use they could ease the joint discomfort occurring
with rheumatoid arthritis. Additionally, it was later observed that
they have similar beneficial effects in the management of these
same symptoms in Systemic Lupus Erythematosus (SLE). Skin lesions
of Discoid Lupus Erythematosus (DLE) which have not responded to
topical therapy (medicated creams, lotions, etc.) may improve with
the use of these "antimalarial drugs".
How do antimalarials
Antimalarials block UV light from damaging skin; have an anti-inflammatory
effect; lower cholesterol levels; inhibit clotting; block cytokines,
which promote inflammation; & most importantly, alter the acid-base
of the cells, which limits their ability to process antigens. (If
antigens were processed, this would lead to the creation of unnecessary
antibodies.) Antimalarials do not lower blood counts, or make
patients more susceptible to infection.
are used in the treatment of lupus?
Hydroxychloroquine (Plaquenil) is available as a 200 mg tablet
and is generally prescribed to be taken as one or two tablets once
or twice daily.
Chloroquine (Aralen) is marketed as a 250 mg tablet which is usually
taken once daily.
Some physicians prefer to prescribe hydroxychloroquine, referring
to some studies which describe evidence that it may have a lower
potential for damage to the retina of the eye. Other clinicians
maintain that the low doses of these agents in common use do not
make this choice critical. Preference for either of these drugs
may be regional, or may reflect training, product familiarity and
Patients with Lupus who may be advised to begin treatment with
these medications include:
Patients who have already been treated with anti-inflammatory
drugs but have experienced inadequate symptom relief or troublesome
Patients who may be able to be controlled with lower doses of
prednisone if they also receive an antimalarial drug (thus avoiding
side effects associated with higher doses of prednisone).
Patients with medical conditions which make it undesirable for
them to be maintained on prednisone or other anti-inflammatory drugs.
What lupus symptoms
can antimalarials help?
Discoid lesions, redness, mouth ulcers & hair loss improve
in 90% of patients. Joint pain & swelling decrease. Over
time, inflammation of the pleura & pericardium lessens, as do
symptoms of fatigue & cognitive dysfunction. Antimalarials
are not effective in the treatment of organ-threatening SLE.
How long does
it take for antimalarials to start working?
It can take anything from 3 weeks to a few months for them to
start working. You may not notice any improvement at first,
but if you stop taking the antimalarials you will often find the
symptoms worsen, therefore the drugs have been working but at a
What are the
side effects of antimalarials?
Side effects which can occur in patients taking hydroxychloroquine
(Plaquenil) or chloroquine (Aralen) include:
More common - diarrhoea, headache, loss of appetite, nausea or
vomiting, stomach cramping or pain.
Less common - bleaching of hair or increased hair loss, blue-black\
discoloration of skin, finger nails, or inside of mouth, dizziness
or light headedness, itching (more common in blacks), nervousness
or restlessness, skin rash.
These side effects may go away after the patient's system adjusts
to the medicine. It is important to check back with the doctor,
however, if they are continuous and bothersome.
Other side effects are more rare and should be reported immediately
to the physician:
- convulsions (seizures)
- increased muscle weakness mood or other mental changes ringing
or buzzing in the ears, or any
- loss of hearing
- sore throat and fever
- unusual bleeding or bruising
Blurred vision or any other change in vision after prolonged treatment
are symptoms which should always be reported immediately to your
doctor. They may represent early signs of toxicity to the retina
of the eye which is generally preventable if reported early. Low
doses, used at present (as noted above), are rarely associated with
retinal toxicity. As a precautionary measure it is recommended that
patients commencing treatment with the antimalarial drugs receive
a baseline ophthalmic evaluation. This examination should be repeated
every six months while taking the medication and for a further period
of time if treatment was discontinued due to visual symptoms. Periodic
routine blood testing (hemoglobin and white blood cell count with
differential) has also been recommended for early detection of other