Anti malaria drugs in 4 chapter Pharmacology

1. Anti microbial drugs
Common microbes causing diseases
 Bacteria......anti bacterial
 Viruses……anti viral
 Fungi………anti fungal
 Protozoa ……antiprotozoal

2. Anti Malarial drugs
What is malaria?. Malaria is an infectious disease caused by
protozoa; plasmodium.
Five species of plasmodium causing malaria in humans
 P. falciparum
 P. vivax,
 P. malariae,
 P. ovale.
 Plasmodium. knowlesi,
Note. P knowlesi is a pathogen of monkeys, but has recently been
recognized to cause illness, including severe disease, in humans
in Asia

5. Diagnosis
 Test
 MP positive microscopy

6. Quinine
According to a legend, an Indian with a high fever
was lost in an Andean jungle(Peru). Thirsty, he
drank from a pool of stagnant water and found that
it tasted bitter. Realizing that the water had been
contaminated by the surrounding quina-quina trees
he thought he was poisoned. Surprisingly, his fever
soon abated, and he shared this accidental
discovery with fellow villagers, who thereafter
used extracts from the quina-quina bark to treat
fever.

7. Common anti malarial drugs
1. Quinine
2. Chloroquine (resochin)
3. Amodiaquine
4. Pyrimethamine
5. Proguanil
6. Primaquine
7. Artemisinin
8. Lumefantrine

8. Chloroquine/quinine
 Antimalarial Action: Chloroquine is a highly effective blood
schizonticide. It is also moderately effective against gametocytes
of P vivax, P ovale, and P malariae but not against those of P
falciparum. Chloroquine is not active against liver stage
parasites.
Mechanism of action: The parasite digests the host cell’s
hemoglobin to obtain essential amino acids from globin protein.
The process releases large amounts of heme, which is toxic to the
parasite. To protect itself the parasite has the ability to
polymerizes the heme to nontoxic hemozoin. Cholroquine/quinine
prevent the polymerization to hemozoin by binding with heme.
The accumulation of heme results in lysis of both the parasite and
the RBC. Chloroquine resistant parasites have acquired an efflux

9.  Chloroquine’s mode of action is associated with heme
detoxification. During intraerythrocytic
development, P. falciparum degrades hemoglobin
down to amino acids (AA) in its acidic food vacuole.
Heme released from hemoglobin (Hb) is toxic and
destroys cellular membranes unless it is converted to
an inert biomineral, termed hemozoin or malaria
pigment. Chloroquine (CQ) binds to heme, thereby
preventing biomineralization of heme. The build-up of
membrane-lytic heme/chloroquine complexes kill the
parasite.

10. What is heme?
 Heme is a cofactor consisting of an Fe²⁺ ion
contained in the centre of a large heterocyclic
organic ring called a porphyrin.

17. Adverse effects (chloroquine)
Nausea, vomiting, abdominal pain, headache,
anorexia, malaise, blurring of vision, . Rare
reactions include hemolysis in glucose-6-
phosphate dehydrogenase (G6PD)-deficient
persons, impaired hearing, confusion,
psychosis, seizures.
Safe in pregnancy.
Patients with psoriasis or porphyria should not
be treated with chloroquine, because an acute
attack may be provoked

21. Self study topics
 Side effects of quinine
 Chloroquine dosing
 Artemether/lumefantrine dose

22. Drugs used for
Leishmaniasis
 Sodium stibogluconate
 Miltefosine

24. Chloramphenicol self study

25. Drugs used for
toxoplasmosis
 Toxoplasmosis is a parasitic disease caused
by Toxoplasma gondii.
Toxoplasma infection occurs by
 Eating undercooked, contaminated meat having
cysts
 Drinking water contaminated with Toxoplasma
gondii cysts
 Acute toxoplasmosis is often asymptomatic,
However, symptoms may manifest and are often
influenza-like: swollen lymph nodes, headaches,
fever, and fatigue, or muscle aches and pains that
last for a month or more

27. Drugs used for toxoplasmosis
 Sulfadiazine
 Pyrimethamine.
 Leucovorin is commonly administered to
protect against folate deficiency