anti-protoza_part 8 , melarsoprol, elfornithine, benznidazole, nifurtomox, toxoplasmosis, pneumocyctis carinii. flashcards
What are the key features of Tinidazole?
Efficiency is similar to metronidazole. Metabolism is slower. Duration of action is longer.
How is Emetine administered, and what are its key features?
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.
What is the mechanism of action of Emetine?
Inhibits protein synthesis in amoebae by arresting intra-ribosomal translocation of tRNA amino acid complex.
What are the uses of Emetine?
Reserve drug for severe intestinal or extra-intestinal amoebiasis. For cases not responding to metronidazole.
What are the adverse effects of Emetine?
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.
What are the uses of Chloroquine in amoebiasis?
Kills trophozoites of E. histolytica. Used only in hepatic amoebiasis. Not effective in invasive dysentery or controlling luminal cysts.
What is the mechanism of action of Diloxanide Furoate?
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.
What are the uses of Diloxanide Furoate?
Drug of choice for treating asymptomatic infections. Used with other drugs for intestinal diseases.
What are the adverse effects of Diloxanide Furoate?
Generally well tolerated. Can cause flatulence, nausea, and abdominal cramps.
What are the features of Amphotericin B?
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.
What are the uses of Amphotericin B?
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.
What are the features of Miltefosine?
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.
What are the drugs for trypanosomiasis?
1) Suramin sodium, 2) Pentamidine isethionate, 3) Melarsoprol, 4) Eflornithine, 5) Nifurtimox, 6) Benznidazole.
What is the treatment of African trypanosomiasis?
Early stage: 1st choice: Suramin sodium, 2nd choice: Pentamidine isethionate. Late stage: 1st choice: Melarsoprol, 2nd choice: Eflornithine.
What are the pharmacokinetics and mechanism of action of Suramin Sodium?
An organic urea compound. Given intravenously, half-life ~50 days. Binds to host proteins and inhibits energy metabolism. Causes clearance of organism from circulation.
What are the uses of Suramin Sodium?
1) Early stage of African trypanosomiasis. 2) Drug of choice for adult worms of Onchocerca volvulus.
What are the adverse effects of Suramin Sodium?
Relatively toxic in undernourished patients. Causes nephrotoxicity, adrenal insufficiency, and skin rashes.
What are the features and uses of Melarsoprol?
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.
What are the adverse effects of Melarsoprol?
Extremely toxic. Vomiting, colicky pain. Hypersensitivity reactions. Encephalopathy.
What are the features and uses of Eflornithine?
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.
What are the features and adverse effects of Benznidazole?
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.
What are the features and adverse effects of Nifurtimox?
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.
What is the treatment of toxoplasmosis?
1) Pyrimethamine sulfadiazine (drug of choice). 2) Trimethoprim + Sulphamethoxazole. 3) Pentamidine isethionate. 4) Azithromycin.
What are the drugs used for Pneumocystis Carinii?
1) Trimethoprim + Sulphamethoxazole. 2) Pentamidine (alternative). 3) Atovaquone. 4) Primaquine + Clindamycin.
