Etiology (study of the cause/ causation of disease or condition): Malaria in humans is caused by four species of Plasmodium (protozoan parasite) Plasmodium Vivax (benign tertian malaria) Plasmodium falciparum (malignant tertian, sub-tertian malaria) Plasmodium malariae (quartan malaria) Plasmodium ovale (mild tertian malaria ovale tertian) In other mammals, birds and reptiles it is caused by many other species.

1. Medicinal Chemistry-III
Antimalarial agents
Department of Pharmacy, Indira Gandhi National Tribal
University, Lalpur, Amarkantak (M.P.)
Dr. Akhilesh Tiwari
Assistant Professor
Department of Pharmacy,
IGNTU, Amarkantak

2. Malaria is transmitted to humans through the female anopheles
mosquito.
Pregnant female mosquitoes require human blood for nourishment.
The malaria parasite is in the saliva of the mosquito that is injected into
the human when the mosquito attempts to draw blood from the human
in the presence of saliva blood clotting is not occurs.

3. If a mosquito does NOT have malaria, but the human host DOES
- then the mosquito will contract the malaria parasite from the
human's blood.
The mosquito will go on to infect its next human host/meal with
malaria.
Red blood cells are important to humans because they
convey oxygen throughout the human body. If red blood cells
stop functioning, the body will Stop functioning

5. Anemia, fever/chills, vomiting, headaches, diarrhea, retardation
(fetal + child dev.)
 False treatment of malaria may cause people to overlook
other health-threatening illnesses
 Lost money
 False treatment and/or over treatment of illness
 Transport, medical costs, etc..
 Can't go to work, can't get new money
 Can't go to school (lost education)
 Can't take care of family
 Lost lives
 Can't socialize
 Can't develop/grow properly Death

6. According to the latest World malaria report, there were 241 million cases of
malaria in 2020 compared to 227 million cases in 2019. The estimated number
of malaria deaths stood at 627 000 in 2020 – an increase of 69 000 deaths
over the previous year. While about two thirds of these deaths (47 000) were
due to disruptions during the COVID-19 pandemic.
DISEASE BURDEN
The WHO African Region continues to carry a disproportionately high share of
the global malaria burden. In 2020 the Region was home to 95% of all malaria
cases and 96% of deaths. Children under 5 years of age accounted for about
80% of all malaria deaths in the Region.
Resistance to artemisinin by Plasmodium
falciparum (the malaria parasite that is
responsible for the majority of deaths from
malaria worldwide)

7. ETIOLOGY
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Etiology (study of the cause/ causation of disease or condition):
Malaria in humans is caused by four species of Plasmodium (protozoan
parasite)
• Plasmodium Vivax (benign tertian malaria)
• Plasmodium falciparum (malignant tertian, sub-tertian malaria)
• Plasmodium malariae (quartan malaria)
• Plasmodium ovale (mild tertian malaria ovale tertian)
In other mammals, birds and reptiles it is caused by many other species.

8. Life cycle of Malarial parasite

9. SH MADHU SODHAN TYAGI, GADI ME ZOO GAYE

10. LIFE CYCLE OF MALARIAL PARASITE
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bite of mosquito.
Faculty of Pharmacy
• Mosquito bites an infected vertebrate and ingests the malarial parasite
• In the stomach of the mosquito, the sexual phase of development
called sporogony occurs.
• The male-female gametocytes form gametes. An ookenite (zygotes) is
formed by fertilization and penetrates the stomach wall outside the
stomach wall. Outside the stomach, oocysts are formed which produces
sporozoites, that are released by the rupturing of the oocyst.
• The sporozoites travel to the salivary glands of the mosquito, from
which they may be transferred to an uninfected vertebrate host by the

11. LIFE CYCLE OF MALARIAL PARASITE
Department of Pharmacy
8
• Injected sporozoites disappear rapidly from the blood of the vertebrate,
entering the parenchyma cells of the liver and some other tissues. The
parasite now begins the asexual phase of development called
schizogony.
• In this pre-erythrocytic stage, the parasite grows and divides to form
schizont. The schizont segment to form many merozoites, which causes
the rupturing of the cell, beginning the erythrocytic stage.
• Within the red blood cells, the merozoites become trophozoites and
multiplication occurs by schizogony .

12. LIFE CYCLE OF MALARIAL PARASITE
Department of Pharmacy
9
• The schizonts formed from the trophozoites divide into merozoites
and continuously increase the no.of merozoites available to invade
more red blood cells, so that, finally the no. of rupturing cells is
sufficiently great to initiate the symptoms of disease.
• The asexual cycle continues until chemotherapy is initiated, immunity
is developed or death occurs.
• The continuous invasion and subsequent rupture of erythrocytes
lead to the development of another significant symptoms of malaria,
anemia.

13. LIFE CYCLE OF MALARIAL PARASITE
13
• When normal reproduction of
the erythrocytes becomes
some
the
unfavorable,
trophozoites from
erythrocyte stage
into male or
develop
female
gametocytes, which circulate
in the blood to be available
for ingestion by another
mosquito.
Faculty of Pharmacy

14. POTENTIAL WAYS TO CONTROL MALARIA
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• Elimination of the vector-simplest, cost effective
Prevent contact with insect- a nocturnal feeder-use window screens, mosquito nets
Eliminate mosquito by application of insectidies & destroy breeding grounds
• Drug therapy-tremendous need for new, more effective drugs
Cause protozoa develop resistance by different mechanisms & there are a variety of
adverse reactions. No single drug is effective against all species
• Vaccination- no effective vaccination has been developed
the parasite does not elicit an effective immune response. The only approved
vaccine as of 2015 is RTS,S,-trade name Mosquirix. It has relatively low efficacy.

15. POSSIBLE SITES FOR DRUG THERAPY
• Kill the sporozoites injected by the mosquito and/or prevent
the sporozoites from entering the body
• Kill the primary schizonts in the hepatocytes and/or prevent
them form becoming merozoites
• Kill the merozoits in the blood and/or prevet them from
developing into gametocytes
• Kill the gametocytes before they enter the mosquito and
fertilize into zygotes
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16. SITES OF ANTI-MALARIAL DRUGS
16

17. MODERN MALARIA CHEMOTHERAPY
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• Most drugs used in modern malarial chemotherapy as chloroquine,
amodiaquine, pyrimethamine, quinine, sulfonamides act primarily
at the erythrocytic stage, in the malaria life cycle (i.e. at site 4).
Since the severe and life threatening clinical symptoms of malaria
occur at the stage, these drugs are very useful in
1. Treating all four human malarias and
2. In preventing clinical symptoms of four human malarias.

18. CLASSIFICATION OF ANTIMALARIALS
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The important classes of antimalarial drugs are:
BSP N CAAA ka virodh nahi kiya
 Biguanides
 Sulfones
 Pyrimidines (diaminopyrimidines)
 Newer antimalarials
 Cinchona alkaloids
 4-aminoquinolines
 8-aminoquinolines
 9-aminoacridines