2. Anti-protozoal Agents
By
Dr. A. S. Tapkir
Department of Pharmaceutical Chemistry,
PES, Modern College of Pharmacy,
Nigdi, Pune-44
3. • Antiprotozoal drugs are agents used to treat variety of protozoal
infections.
• Protozoa are unicellular eukaryotes, therefore, they have metabolic
processes closer to those of the human host than to prokaryotic
bacterial pathogens. Therefore, protozoal diseases are less easily
treated than bacterial infections, and many of the antiprotozoal
drugs cause serious toxic effects in the host, particularly on cells
showing high metabolic activity.
Anti-protozoal Agents
9. Anti-protozoal Agents
Ornidazole,
1-Chloro-3-(2-methyl-5-nitro-1H-
imidazol-1-yl)propan-2-ol
Ornidazole is a nitro imidazole which has broad
spectrum cidal activity against Protozoa and some
anaerobic bacteria.
Its selective toxicity to anaerobic microbes involves
1. Drug enters the cell by diffusion,
2. Nitro group of drug is reduced by redox proteins
present only in anaerobic organisms to reactive nitro
radical which excerts cytotoxic action by damaging
DNA and other critical biomolecules.
3. DNA helix destabilization &strand breakage has
been observed.
10. Anti-protozoal Agents
Diloxanide
4-[(Dichloroacetyl)(methyl)amino]phenyl
furan-2-carboxylate
• Diloxanide furoate is a white crystalline powder
• orally only as 500-mg tablets
• Possessed amebicidal activity
• Nonpolar esters of diloxanide are more potent
than polar ones
• Diloxanide is a luminal amebicide, however the
mechanism of action of diloxanide is unknown.
Diloxanide destroys the trophozoites of E.
histolytica that eventually form into cysts. The
cysts are then excreted by persons infected with
asymptomatic amebiasis. Diloxanide furoate is a
prodrug, and is hydrolyzed in the gastrointestinal
tract to produce diloxanide, the active ingredient.
11. Anti-protozoal Agents
Iodoquinol
5,7-Diiodoquinolin-8-ol
• is a yellowish to tan microcrystalline.
• light-sensitive substance that is insoluble in
water.
• It is recommended for acute and chronic
intestinal amebiasis but is not effective in
extraintestinal disease. Because a relatively high
incidence of topic neuropathy has occurred with
its use.
12. Anti-protozoal Agents
Atovaquone,
2-[4-(4-Chlorophenyl)cyclohexyl]-
3-hydroxy-1,4-naphthalenedione
• is a highly lipophilic water-insoluble analogue of
ubiquinone. an essential component of the
mitochondrial electron transport chain in
microorganisms.
• Interfere with the function of electron transport
enzymes.
• Atovaquone was originally developed as an
antimalarial drug, hut Piasmodium fulciparam was
found to develop a rapid tolerance to its action
13. Anti-protozoal Agents
Eflornithine
2,5-Diamino-2-(difluoromethyl)pentanoic acid
• Eflornithin an amino acid derivative, is an
enzyme activated inhibitor of ornithine
decarboxylase
• A pyridoxal phosphate—dependent enzyme
responsible for catalyzing the rate-limiting
step in the biosynthesis of the diamine
purine and the polyamines spermine and
spermidine.
• Poly amines are essential for the regulation
of DNA synthesis and cell proliferation in
animal tissues and microorganisms.
14. 14
Thank You
Dr. Amit S. Tapkir
Assistant Professor
Department of Pharmaceutical Chemistry
P. E. Society's
Modern College of Pharmacy
Yamunanagar, Nigdi, Pune 411044
Email id : amittapkir.8@gmail.com
