drugs pharmacology medicine

1. Anti-Amoebic drugs (Anti-Protozoal)
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2. Anaerobic organisms
 An anaerobic organism or anaerobe is any organism that does not require
oxygen for growth.
 It can be either bacteria or protozoa
1. Bacteria:
 Clostridium tetani (Tetanus),
 Clostridium perfringens (Gas Gangrene)
 Clostridium botulinum (Botulism)
 Clostridium difficile (Pseudomembranous Colitis)
 Actinomyces (head, neck, pelvic infections; aspiration pneumonia)
 Helicobacter pylori (facultative anaerobic bacteria)
 Fusobacterium (abscesses, wound infections)
2. Protozoa: Trichomonas, Giardia and Entamoeba
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3. Difference Between Aerobic and Anaerobic
Bacteria
 The bacteria that grow in the presence of oxygen are called aerobic bacteria. They have the ability to
detoxify oxygen free radical with the help of enzymes(antioxidants)
 The bacteria that grow in the absence of oxygen are called anaerobic bacteria. It does not have the
ability to detoxify oxygen. They are with out antioxidants.
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4. Anti-parasitic
 Parasites : They are single celled, small sized microorganisms
 Parasitology: The branch of microbiology in which we study parasites
 Antiparasitic: are a class of medications which are indicated for the treatment of parasitic
diseases, such as those caused by helminths, amoeba, ectoparasites, parasitic
fungi, plasmodium, and toxoplasma.
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5. Common human parasites
 Entamoeba
 Giardia
 Trichomonas
 Plasmodium
 Toxoplasma
 Leishmania
 Taenia solium (helminths)
 Ascaris lumbricoides (helminths)
 Lice
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6. Amebiasis, giardiasis
 Amebiasis is caused by Entamoeba histolytica
 The highest prevalence of amebiasis is in developing countries where barriers between human
feces and food and water supplies are inadequate.
 E histolytica is transmitted via ingestion of the cystic form (infective stage) of the protozoa via
food, water etc.
 The cysts are then converted to trophozoites (invasive form). The trophozoites can penetrate and
invade the colonic mucosal barrier.
Symptoms
Dysentery: Infection of the intestines resulting in severe diarrhea with the presence of blood and
mucus in the feces.
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8. Life cycle of Entamoeba Histolytica
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9. Classification of anti-Amebic drugs
1) Drugs affective in intestinal, luminal,
or local Amoebiasis.
 Members include:
 Diloxanide
 Iodoquinolone
2) Drugs effective only in tissue or
hepatic Amoebiasis.
Members include:
 Chloroquine
 Dehydroemetine
3) Drugs effective in both intestinal
and hepatic Amoebiasis.
 Members include
 Metronidazole
 Tinidazole
 Ornidazole
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o Three major groups are as follows

10. METRONIDAZOLE
Nitroimidazole
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11. Antiprotozoal spectrum of Metronidazole
-Antiprotozoal spectrum includes:
Entamoeba Histolyticum
Giardia Lamba
Trichomonas Viginalis
Bacteroides (Gram negative
Bacilli)
Clostridium Difficile (Gram
Positive Bacilli)
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12. Mechanism of action of Metronidazole
 The reduced product of Metronidazole, nitro radical, reacts with DNA or Protein and
damages them thus causing killing of microbes
 Nitro group in metronidazole acts as an electron acceptor, forming its derivatives by
reduction.
 These reduced componds (Derivatives) have cytotoxic action on protozoal cell.
 These compound will precipitate the proteins and DNA of protozoal cell
 Eventually Protozoal cell will die.
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13. Clinical uses of metronidazole
 Anaerobic and mixed intra-abdominal infections
 Amoebiasis
 Aspirational Pneumonia
 Giardiasis
 Vaginosis (Trichomonal vaginitis)
 Pseudo membranous colitis (C. difficile colitis)
 Peritonitis
 Brain abscess
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14. Adverse affects of Metronidazole
1) GIT:
 Nausea
 Vomiting
 Diarrhea
 Abdominal cramps
 Epigastric distress
 Unpleasant
metallic taste of
mouth
2) CNS:
 Dizziness
 Vertigo
 Paresthesia
(Numbness / No
sense of touching)
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15. Drug interactions
 Metronidazole has been reported to potentiate the anticoagulant effect of warfarin and
other oral coumarin anticoagulants, resulting in a prolongation of prothrombin time.
oResistance
 Resistance to metronidazole is not a therapeutic problem.
 Trichomonads strains sometimes develop resistance.
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16. Thank You!
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