This document discusses various antimalarial drugs used for prophylaxis, treatment, and prevention of malaria caused by Plasmodium parasites transmitted through mosquito bites. It provides details on the classes of antimalarial drugs like chloroquine, mefloquine, quinine, artemisinin derivatives, and their mechanisms of action in inhibiting the parasite. It also lists the dosage recommendations for different antimalarial drugs across age groups.

2.  Antimalarial drugs used for
 Prophylaxis
 Treatment
 Prevention of malaria.

3.  Malaria is one of the major communicable
diseases affecting mankind.
 It is caused by plasmodium parasite, which is
transmitted by the bite of infective female
anopheles mosquito.

4.  There are four plasmodium species important to
mankind, p.vivax, p.falciparum, p.malaria, and
p.ovale.

6.  Chloroquine
 Amodiaquine
 Piperaquine
 Mechanism of action: it concentrates with in
parasite acid vesicles and raises internal ph
resulting in inhibition of parasite growth.

7.  Choloroquine is rapidly acting against all the
species of plasmodium.
 It has anti-inflammatory, and local anesthetic,
weak smooth muscle relaxant, antihistamine
and antiarrhythmic properties.

8. Age in years Dose Chloroquine phosphate
( No of tablets )
Day 1 day 2 day 3
>1 75mg 1/2 1/2 1/4
1-4 150mg 1 1 1/2
5-8 300mg 2 2 1
9-14 450mg 3 3 1 1/2
15 and
above
600mg 4 4 2

9.  Mefloquine
 Mechanism of action: it binds with heme and
forms a complex which damages the parasite’s
membrane.

10.  250 mg per week preferably 1-2 weeks.

11.  Quinine
 Quinidine
 Mechanism of action:
 it inhibits the polymerization of heme to
hemaozoin, so free heme damages parasite
membranes.

12.  Quinine destroys erythrocytic forms of the
parasite similar to chloroquine,
 But less effective and more toxic
 It has mild analgesic and antipyretic actions
 Also act as local anesthetic and has skeletal
muscle relaxant properties.

13.  It is given orally for uncomplicated chlorine
resistant malaria and I.V for complicated or
cerebral malaria.

14.  The 7 day quinine + doxycycline/ clindamycin is
the 2nd line treatment of chlorine resistant
malaria.
 Quinine 10mg/kg between 8 hourly in 5%
dextrose saline is preferred in case of
complicated and severe malaria.

15.  Proguanil
 (chloroguanide)
 Mechanism of action:
 It inhibits the pre-erythrocytic stage of
plasmodium falciparum.

16.  Proguanil has little role in prophylaxis or in
clinical cure of malaria.used in
 Atovaquone-proguanil is a used in travellers as a
prophylaxis for chloroquine resistant
plasmodium falciparum.

17.  Pyrimethamine
 Mechanism of action:
 It inhibits the enzyme dihydrofolate reductase,
there by impeding reduction of dihydrofolic acid
to tetrahydrofolic acid to tetrahydrofolic acid.

18.  Pyrimethamine is used in combination with
sulfonamide to treat falciparum malaria.
 It is used in dosage of sulfadoxine 1,500mg +
pyrimethamine 75mg (3tab) single dose
 Children 9-14 years 2tab, 5-8 year 1 ½ tablet,
 1-4 year 1 tablet.

19.  Primaquine
 Tafenoquine
 Mechanism of action: It eliminates primary
tissue exoerythrocytic forms of p.falciparum,
disrupts mitochondria and binds to DNA.

20.  It is active against the pre erythrocytic stage of
p.falciparum , than that of p.vivax .

21. Age in years Primaquine (7.5 mg
base )
No of tablets ( 1 day)
<1 Nil 0
1-4 7.5mg 1
5-8 15mg 2
9-14 30mg 4
15 and above 45mg 6

22. Age in years Primaquine 2.5 mg
base
Daily for 14 days
( no of tablets)
<1 Nil 0
1-4 2.5 mg 1
5-8 5.0 mg 2
9-14 10.0 mg 4
15 and above 15.0 mg 6

23.  Sulfadoxine (bacteriostatic)
 Sulfamethopyazine ( bacteriostatic)
 Dapsone ( anti-inflammatory)
 Mechanism of action:
 It inhibits the di-hydrofolate reductase of
plasmodia and there by blocks the DNA
synthesis and cell multiplication,
 which leads to failure of nuclear division.

24.  Injectable forms of artemisinin derivatives are
used for management of severe and complicated
malaria.

25. Drug Dosage
Artesunate 2.4 mg/kg given IM/IV followed by 1.2
mg/kg after 12 hours then 1.2 mg/kg once
daily for total duration of 5 days.
Artemether 1.6 mg/kg IM followed by 1.6mg/kg daily
for total of 6 injections
(or) 1.6 mg/kg IM injection twice daily for 3
days, a total of 6 injections.

26. Arteether
150 mg daily IM for 3 days in adults only
Artemisinin 10mg / kg at 0 and 4 hours followed by 7
mg/kg at 24, 36, 48 and 60 hours.

27.  They are used in case of uncomplicated
falciparum and for severe and complicated
falciparum malaria.

28.  Tetracycline
 Doxycycline
 Clindamycin
 Mechanism of action:
 They are bacteriostatic antibiotics that bind to
the 30s subunit of the ribosome and prevent the
binding of tRNA to the ribosome, thus inhibiting
bacterial protein synthesis.

29.  Artesunate
 Artemether
 Arteether
 Arterolane
 Mechanism of action:
 It interacts with heme resulting in the generation
of free radicals that bind to the membrane
protein and damages the parasite membrane.

30.  Halofantrine
 Lumefantrine
 Mechanism of action:
 Similar to that of chloroquine, quinine, and
mefloquine, by forming toxic complexes with
ferriprotoporphyrin Ix that damage the
membrane of the parasite.

31.  Pyronaridine

32.  Atovaquone
 Mechanism of action:
 It appears to interfere with electron transport in
protozoal mitochondria, inhibiting enzymes
needed for the synthesis of nucleic acids and
adenosine triphosphate.

33.  Use cautionly in patients with
 -renal failure
 Severe GI problems
 Neurologic
 Cardiac diseases
 History of depression
 Hemolytic anemia

34.  - impaired hepatic function
 -Bronchial asthma or blood disorders.
 Use cautionly in elderly patients with renal and
cardiac problems.

35.  Admister the drugs with food or milk.
 Monitor liver function test to prevent toxic
effect.

36.  Explain importance of daily drug intake.
 Educate take the medicine with food.
 Instruct the prophylaxis measures as
 -protective clothing
 -Bed nets
 -insect repellents.
 -instruct to report adverse effects if any