Drug used in protozoal infections

1. SUBJECT: ADVANCED PHARMACOLOGY 2
CLASS: M PHARMACY 2ND SEM
(PHARMACOLOGY)
G H G KHALSA COLLEGE OF PHARMACY

2.  The Protozoal infectionsinclude:
 Malaria,
 Amebiasis,
 Leishmaniasis,
 Trypanosomiasis,
 Trichomoniasisand
 Giardia.
Protozoal infections are common inUnderdeveloped
tropical and subtropicalcountries.
 They spread as a resultof in adequatesanitaryconditions,
unhygienic practices and poor control of the vectors of
transmission.

3.  Malaria is an acute infectiousdiseasecaused by fourspecies of
Plasmodium (P. falciparum, vivax, malariae andovale)
 Plasmodium falciparum is the most dangerous species
causing an acute, rapidly fulminating disease, chatacterizedby
persistent high fever, orthostatic hypotension and massive
erythrocytosis, leading to capillary obstruction, cerebral state
and death.
 Plasmodium Vivax causes benign tertian malaria. Itis
widespread but not fetal.
 Plasmodium Malarae causes quartan malaria . It isgenerally
mild but can lead tonephrosis.
 Plasmodium Ovale causes ovale tertian malariaand is the
leas common.

4.  Plasmodium Life Cycle
 The life cycleof plasmodium iscomposed of:
 Sexual Phase (Sporogony) in the mosquito andthe
Asexual Phase (Schizony) in man ashost.
 Asexual cycle (In the human): twophases
 Exoerythrocytic phase:- occurs “outside” theerythrocyte
and in the liver.
 Erythrocytic phase:- occurs “inside” theerythrocyte
Erythrocytes = Red Blood Cells (RBCs)
 The Antimalarialsattack the parasiteduring theasexual
phase, when it isvulnerable.

5. Sites of action for antimalarialdrugs.
i) DRUG EFFECTIVE AGAINST EXOERYTHROCYTIC FORM:
(TISSUE SCHIZONTOCIDES)
 Thesedrugs act on the primary tissue form of the plasmodium
and are mainly used for casualprophylaxis.
EXAMPLES
 Primaquine
 Proguanil (chloroquine+paludrine)
 Malarone (proguanil+artovaquin)
 Chloroquine
 Fansidar (Pyrimethamine+sulphadoxine)
 Pyrimethamine

6. II) DRUGS EFFECTIVE AGAINST ERYTHROCYTE(ASEXUAL)
FORM(BLOOD SCHIZONTOCIDES)
 Theyproduceclinical & suppressivecureof all the 4 speciesof
malaria parasites.
 Artemisinin- Artemeter+Lumefantrine (Coartem), Atesunatetabs
 Chloroquine tabs, inj.
 Quinine
 Mefloquine(Lariam)
 Pyrimethamine
 Halofantrine hydrochloride (Halfan)
III) DRUG EFFECTIVE AGAINST GAMETOCYTICFORM:
(GAMETOCYTES)
 Theydestroythesexual formof theparasites to interruptthe
transmission of malaria.
 Primaquine
 Quinine
 Chloroquine

7. ADR OF ANTIMALARIALS:
 GIT disorders:- anorexia, nausea,vomiting
 Ocular effects:- difficulty infocusing,
 Headache, dizziness, emotional change,tachycardia,
Bradycardia, etc..
 INTERACTION:
 Oral antacids- inhibit the absorption ofantimalarials
 Beta blockers, Calcium channel blockers & Folic acid-also
inhibit the effect ofantimalarials.

8.  Amebiasis is alsocalled amebic dysentery, is an infection
of the intestinal tract caused by Entamoebahistolytica.
 Can be acute orchronic.
 From asymptomatic to mild diarrhea and to fulminant
dysentery.
 Intestinal disease: Invadeand ulcerate the mucosaof the
large intestine orcolon.
 Luminal amebiasis: Non invasivecolonization.
 Systemic amebiasis: Brain, lung and liver.

9. Classification of amebicidal drugs
i) MIXED AMEBICIDES
 (luminal and systemicactivity)
 Metronidazole tabs 200mg, 250mg, 400mg, or 500mgtds
 Metronidazole is the Drug of choice fortreating amebic infections.
 Used in the treatment of Giardia lamblia, Trichomonas vaginalis,
Anaerobiccocci, and Anaerobicgram-negative bacilli (Bacteroidesspecies),
drug of choice in the treatmentof pseudomembranouscolitiscaused by the
anaerobic, gram-positive bacillus (clostridium difficile) and brain abscesses
caused by theseorganisms
ii) SYSTEMIC AMEBICIDES
 (intestinal wall and liver)
 Chloroquine tabs250mg
 Dehydroemetine
 Emetine

10. III) LUMINALAMEBICIDES
 (parasite in the lumen of thebowel)
 Diloxanide furoate
 Paramomycin
 Iodoquinol
ADR OF AMEBIASIS DRUGS: Nausea, vomiting,
epigastric distress, abdominal cramps, metallic taste,oral
moniliasis, dizziness andvertigo.
 They should not be taken with alcohol, adisulfiram-like
effectoccurs.

11. ForAsymptomatic cystcarriers Drugseffectiveare:-
 Iodoquinol or
 Paramomycin or
 Diloxanide furoate.
For those with Diarrhea/DysenteryExtraintestinal:-
 Metronidazol plus
 Iodoquinol or
 Paramomycin or
 Diloxanide furoate
Forthosewith Amoebic liverabscess:-
 Chloroquine plus
 Metronidazoleor
 Emetine.

12. TRYPANOSOMIASIS has many names:-
AMERICAN:
 Chagasdisease
 Caused by Trypanosomacruzi.
 Causescardiomyopathy.
 Transmitted by inset feces contaminating theeye or break in the skin.
 Treated with nifurtimox.
AFRICAN:
 Slepping sickness
 Caused by T. brucei gambiense.
 Treated with suramin and pentamidine only in theearly stagesof the
disease.
 T. brucei rhodesiense.
 Usually fatal if nottreated.
 Treated with melasoprolol when there is CNSinvolvement.

13.  There are three types of leishmaniasis:cutaneous,
mucocutaneous, and visceral (liver andspleen)
 Is transmitted from animals to humans, and between
humans, by the bite of infected sandflies.
 Sodium stibogluconate is the drug of choice forvizceral
Leishmaniasis.
 Amphotericin B is used with oraftersodium
stibogluconate.

14. TOXOPLASMOSIS is caused by Toxoplasmagondii.
 Transmitted to humanswhen theyconsume rawor inadequately
cooked infected meat.
 An infected pregnantwomancan transmit theorganism to the fetus.
 Cat shed oocysts.
 The drug of choice is the antifolate drug:
 pyrimethamine
 sulfadiazine and pyrimethamine
 trimethoprim and sulfamethoxazole.
 Is caused by Toxoplasmagondii.
 Transmitted to humanswhen theyconsume rawor inadequately
cooked infected meat.
 An infected pregnantwomancan transmit theorganism to the fetus.
 Cat shed oocysts.

15. GIARDIA LAMBLIA is an intestinalparasite.
 Infection occur by the ingestion of cysts in contaminated water
or food, or by the fecal-oralroute.
 Can occur severediarrhea.
 The drug of choice: metronidazole.
 Alternative: tinidazole or mepacrine hydrochloride.
TRICHOMONACIDES is a bacterial infection thatcauses:-
 Trichomona vaginalis infection
 Contact tracingis recommended and sexual contact shouldbe
treated simultaneously.
 Drug of choice: metronidazole
 Alternative: tinidazole

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