Evening star., 1952-10-24
Army Tests Most Potent
Of fAnti-MuIuriu Druqs
Work Spurred by Relapse Rate
Of Soldiers From Korea
By Thomos R. Henry

Most potent of all anti-malaria drugs
now is being evaluated by the Army, the
Public Health Service and the National
Research Council.
The work has been spurred by the
exceptionally heavy relapse rate of SOL
diers returning from Korea. The drug
is primaquine, synthetic substance
built up on the quinine model. which
still is in such short supply that its use
must be restricted to the investigating
agencies.
When troops first entered Korea in
1850 all were given doses of q malaria
suppressing drug. chloroquine. It holds
off the overt symptoms of malaria. but
it does not prevent infection with the
malaria parasite.
In the spring of 1851, when large
numbers Of troops were returned to the
United States and use of chloroquine
was discontinued. attacks of malaria
began to occur with increasing frequen-
cy. A peak of more than 600 such re-
lapses was recorded in one week. Acute
attacks could be terminated, for the time
being, with more chloroquine-but they
would recur again.
The best remedy up to that time was
drug known as pamaquine; but prima-
quine, manufacture of which had just
started, was believed to have numerous
advantages. Up to date. according to q
report to the American Medical Asso-
citation, a single minute dose Of prima-
quine daily for IA consecutive days will
reduce the relapse rate Of Korean ma
laria to less than one per cent. In .
control group of $50 men treated with
chloroQuine alone the relapse rate has
been found to be 80 per cent, and 1t still
is increasing. In similar group treated
with both chloroquine and primaquine
there has been only one relapse.
A serious problem with any new drug
is that of possible toxicity. To determine
this primaquine was administered to
over 800 natives in a jungle area OF
Nicaragua, $500 soldiers in the United
States and to 2.700 returning from
Korea. No evidence Of any poisonous
effect, with the amounts given, has been
observed to date.
No bad reactions have been observed
when primaQuine and chloroquine
are given together, but the experiment.
ers are aware that there Is real danger
from overdosage. PrimaQuine Is quite
closely related to pamaquine and, 1t 10
probable, has the same toxic potentiali-
ties-especially causing anemia by sup.
preston Of the activity Of the bone mar
row.
Maximum Dose Determined.
The maximum tolerated dose Of pri-
maquine in white men. 1t has been
determined, Is more than twice the
maximum dose Of pamaquine. It Is
considerably more toxic for the colored
races than for Caucasians. Doses OF
twice the amount being given routinely.
it has been found produce no bad re.
action among white soldiers, but occa-
sionally cause serious anenia in Negro
soldiers. The danger is sufficient. 1t Is
pointed out, to require blood tests with
any untoward symptoms.
The drug is being used against the
temperate zone type of vivax malaria
which has long latent period of eight
to nine months and is adapted to live
in the blood through long winters in
which 1t Is not transmitted to others.
There Is tropical zone type Of the same
organism from which there may be
relapse at any time. The Korean cases.
it is believed. are all Of the temperate
zone type.
Up to the present thousands of syn
thetic drugs have been tested for action
against malaria. Only those of one
family, to which primaquine and pama-
quine both belong, have shown any pro-
nounced curative action. OF these pri-
maquine seems by far the better. It
was synthesized at Columbia University
during the last war, but it could not be
tested adequately until the war was over.
Then it was tried out extensively with
animals in Nicaragua and with prisoner
volunteers at the Federal penitentiary in
Atlanta.