Pharmacology for Dentistry

352 Section 9/ Chemotherapy

ACRIDINE DERIVATIVE

MEPACRINE

It is an erythrocytic schizontocide
related to its ready intercalation into DNA.

Readily absorbed from the GI tract even
in the presence of severe diarrhoea. It is
widely distributed in the tissues and is
eliminated very slowly.

Adverse effects include urticaria,
exfoliative dermatitis, GI disturbances,
dizziness and yellow discoloration of the
skin on prolonged use.

It is indicated in drug resistant P.
falciparum malaria and in the treatment of
giardiasis.

CINCHONA ALKALOIDS

QUININE

Quinine is a natural alkaloid obtained
from cinchona bark.

It is erythrocytic schizontocide and is
effective against all species of plasmodia.
It has no effect on preerythrocytic stage and
on hypnozoites of relapsing malaria. It kills
the gametes of P. vivax.

It also has anaesthetic, local irritant
action. Quinine causes hypotension,
cardiac depression (IV injection), stimulates
myometrium and rapid IV injection causes
hypoglycaemia.

It is highly concentrated in the acidic
food vacuoles of the parasite where it
inhibits haem polymerase leading to the
accumulation of haem which is cytotoxic.

Adverse effects include nausea,

vomiting, epigastric discomfort, skin rash,

itching, hypotension, haemolysis, blurred

vision, vertigo, tinnitus and cinchonism.

It is used in the treatment of cerebral

falciparum malaria and multidrug resistant

strains of cerebral malaria. It is also used

along with clindamycin in the treatment

of babesiosis. It is also effective in myotonia

congenita and nocturnal muscle cramps.

BIGUANIDES

PROGUANIL

It is an effective erythrocytic

schizontocide against P. falciparum and P.

vivax but slower acting than chloroquine.

The active triazine metabolite, inhibits

plasmodial dihydrofolate reductase and

thus disrupts the synthesis of nucleic

acids in the parasite.

It is slowly but adequately absorbed

from the GI tract. It is metabolised in the

liver to the active metabolite cycloguanil.

Adverse effects include gastrointesti-

nal disturbances, nausea, vomiting, diar-

rhoea, abdominal pain and haematuria.

It is mainly used in prophylaxis of

malaria in combination with chloroquine

in areas with low chloroquine resistance

among P. falciparum. It can be safely used

in pregnancy.

DIAMINOPYRIMIDINE & SULFONAMIDES

PYRIMETHAMINE

It is an inhibitor of plasmodial