anti-protoza_part 8 , melarsoprol, elfornithine, benznidazole, nifurtomox, toxoplasmosis, pneumocyctis carinii. flashcards

Question 1

What are the key features of Tinidazole?

Answer 1

Efficiency is similar to metronidazole. Metabolism is slower. Duration of action is longer.

Question 2

How is Emetine administered, and what are its key features?

Answer 2

Administered via S/C or IM route (not orally due to vomiting). Concentrated in certain tissues. Excreted slowly (over 1+ months). Provides symptomatic relief in 1–3 days but is not curative (no effect on cysts). Highly effective in liver abscess.

Question 3

What is the mechanism of action of Emetine?

Answer 3

Inhibits protein synthesis in amoebae by arresting intra-ribosomal translocation of tRNA amino acid complex.

Question 4

What are the uses of Emetine?

Answer 4

Reserve drug for severe intestinal or extra-intestinal amoebiasis. For cases not responding to metronidazole.

Question 5

What are the adverse effects of Emetine?

Answer 5

1) Local reactions: Pain, tenderness, occasional sterile abscess. 2) GIT: Nausea, vomiting, diarrhea. 3) CVS: Hypotension, tachycardia, myocarditis, heart failure. 4) Neuromuscular: Muscle weakness, stiffness, tenderness, tremors.

Question 6

What are the uses of Chloroquine in amoebiasis?

Answer 6

Kills trophozoites of E. histolytica. Used only in hepatic amoebiasis. Not effective in invasive dysentery or controlling luminal cysts.

Question 7

What is the mechanism of action of Diloxanide Furoate?

Answer 7

Directly acts as a luminal amoebicide. Hydrolyzed in the intestine into diloxanide and furoic acid. Released diloxanide (about 90%) is absorbed and conjugated in the liver. Unabsorbed diloxanide acts as the active antiamoebic agent.

Question 8

What are the uses of Diloxanide Furoate?

Answer 8

Drug of choice for treating asymptomatic infections. Used with other drugs for intestinal diseases.

Question 9

What are the adverse effects of Diloxanide Furoate?

Answer 9

Generally well tolerated. Can cause flatulence, nausea, and abdominal cramps.

Question 10

What are the features of Amphotericin B?

Answer 10

Effective against sodium stibogluconate-resistant mucocutaneous disease and visceral leishmaniasis. Forms pores in cell membranes leading to ion leakage and cell death. Liposomal amphotericin B is the drug of choice for visceral leishmaniasis due to shorter course and lower toxicity.

Question 11

What are the uses of Amphotericin B?

Answer 11

Limited by toxic effects. Liposomal amphotericin B used in endemic areas with Miltefosine for 1-2 weeks. Effective as a single-dose treatment for visceral leishmaniasis.

Question 12

What are the features of Miltefosine?

Answer 12

Only oral agent effective against leishmaniasis. Used for visceral and cutaneous leishmaniasis. Acts by lipid-dependent cell signaling, mitochondrial dysfunction, and apoptosis. Adverse effects include gastrointestinal distress and elevated creatinine.

Question 13

What are the drugs for trypanosomiasis?

Answer 13

1) Suramin sodium, 2) Pentamidine isethionate, 3) Melarsoprol, 4) Eflornithine, 5) Nifurtimox, 6) Benznidazole.

Question 14

What is the treatment of African trypanosomiasis?

Answer 14

Early stage: 1st choice: Suramin sodium, 2nd choice: Pentamidine isethionate. Late stage: 1st choice: Melarsoprol, 2nd choice: Eflornithine.

Question 15

What are the pharmacokinetics and mechanism of action of Suramin Sodium?

Answer 15

An organic urea compound. Given intravenously, half-life ~50 days. Binds to host proteins and inhibits energy metabolism. Causes clearance of organism from circulation.

Question 16

What are the uses of Suramin Sodium?

Answer 16

1) Early stage of African trypanosomiasis. 2) Drug of choice for adult worms of Onchocerca volvulus.

Question 17

What are the adverse effects of Suramin Sodium?

Answer 17

Relatively toxic in undernourished patients. Causes nephrotoxicity, adrenal insufficiency, and skin rashes.

Question 18

What are the features and uses of Melarsoprol?

Answer 18

Features: A prodrug metabolized to melarsen oxide (active form). Acts by irreversibly binding to sulfhydryl groups on pyruvate kinase, disrupting energy production in the parasite. Uses: Treatment of late-stage T. brucei gambiense with CNS involvement.

Question 19

What are the adverse effects of Melarsoprol?

Answer 19

Extremely toxic. Vomiting, colicky pain. Hypersensitivity reactions. Encephalopathy.

Question 20

What are the features and uses of Eflornithine?

Answer 20

Features: Second-line therapy for late-stage (meningoencephalitis stage). Inhibits ornithine decarboxylase enzyme. Half-life ~3 hours, crosses the blood-brain barrier. Adverse Effects: Diarrhea, vomiting. Anemia, thrombocytopenia, leukopenia. Seizures.

Question 21

What are the features and adverse effects of Benznidazole?

Answer 21

Features: Good oral bioavailability. Inhibits DNA, RNA, and protein synthesis by free radicals. DOC in the acute phase of Chagas’ disease (success rate ~80%). Adverse Effects: Rash, GIT symptoms. Peripheral neuropathy. Myelosuppression.

Question 22

What are the features and adverse effects of Nifurtimox?

Answer 22

Features: Well-absorbed orally. Plasma half-life ~3 hours. Produces toxic oxygen-free radicals. Second choice for acute stage American trypanosomiasis. Adverse Effects: Serious allergic skin reactions. GIT disturbances. Neurological toxicity.

Question 23

What is the treatment of toxoplasmosis?

Answer 23

1) Pyrimethamine sulfadiazine (drug of choice). 2) Trimethoprim + Sulphamethoxazole. 3) Pentamidine isethionate. 4) Azithromycin.

Question 24

What are the drugs used for Pneumocystis Carinii?

Answer 24

1) Trimethoprim + Sulphamethoxazole. 2) Pentamidine (alternative). 3) Atovaquone. 4) Primaquine + Clindamycin.