Antivirals, Antifungals, Antiparasitics Flashcards
Name 3 treatment options for HSV and VZV
- Acyclovir
- valaciclovir (prodrug)
- famciclovir (prodrug of penciclovir)
Not ganciclovir! Reserved for CMV due to severe side effects
Moa acyclovir?
Inhibit DNA synthesis during viral replication by phosphorylation by viral thymidine kinase. Guanine analogue. Irreversible inactivation viral DNA polymerase.
Name 2 treatment options for CMV
- Ganciclovir
* valganciclovir
Moa ganciclovir?
Synthetic nucleoside analogue structurally related to acyclovir.
Acts as substrate for viral DNA polymerase (inactivate) and as a chain terminator aborting virus replication.
Name 2 adverse effects ganciclovir
- Neutropenia
* thrombocytopenia
Name 2 neuraminidase inhibitors
• Zanamivir inhalations
• oseltamavir oral
Antivirals for influenza A or B
Moa neuraminidase inhibitors ?
Inhibit release newly synthesized viruses from host cell by inhibit enzyme neuraminidase, responsible for cleaving peptide links between virus and host
Treatment of influenza A or B?
Neuraminidase inhibitors: oseltamivir or zanamivir
Must treat within 48 hours after onset symptoms for any patients when its endemic in community
Which drug classes can be used to treat chronic hepatitis c?
- protease inhibitors (NS3 proteins)
- NS5A inhibitors
- polymerase inhibitors (ns5b)
Treatment chronic hepatitis B first line?
Tenofovir (NRTI)
What makes ketoconazole absorption better?
More acidic environment git
Name an antifungal class that targets cell wall with examples
Echinocandins (iv) - fungicidal
•Micafungin
• caspofungin
• anidulafungin
Name 3 antifungal that targets cytoplasmic membrane
- Polyenes: nystatin, amphotericin B
- azoles: fluconazole, itraconazole (target moulds)
- allylamines: terbinafine
Name an antifungals that target nucleic acid synthesis
Flucytosine
Name 2 indications echinocandins
Eg micafungin
• Candida auris and parapsilosis bloodstream infections if mic high and any candidaemia in renal dysfunction
• all candida infections from sterile sites resistant to fluconazole and amphotericin B, and any patient with invasive candida and renal dysfunction
Indication amphotericin B?
Broad spectrum in potentially fatal systemic fungal infections
Indication nystatin?
Suppress candidiasis (thrush) on skin and mucous membranes: oral and vaginal
Name 2 adverse effects polyenes
Eg amphoterecin B
• thrombophlebitis
• nephrotoxicity
Indication fluconazole? (4)
Wide range, including second line cryptococcal meningitis
Endemic coccidioïdes immitis infection
Oropharyngeal candidiasis
Prophylaxis invasive candidiasis
Name 4 indications itraconazole
- Candidiasis later line
- blastomycosis
- histoplasmosis
- sporotrichosis
- aspergillosis
- mucorales (also fluconazole)
Treatment of choice for invasive aspergillosis?
Voriconazole
Flucytosine indications? (2)
- Cryptococcal meningitis in combination with amphotericin B!
- most active against yeasts: systemic candidiasis
Name 2 nb side effects flucytosine
- Bone marrow suppression
* hepatotoxic
Which types parasites more resistant to drugs?
Protozoans.
Allylamines indications?
Eg terbinafine
Dermatophyte infections including ringworm where oral therapy appropriate due to site and severity
Name 5 antifungals for nematodes
Aka roundworms • mebendazole! • albendazole • pyrantel pamoate • ivermectin • diethylcarbamazine
Name 3 antifungals for cestodes
• Praziquantel!
• albendazole
. Niclosamide
Name 2 antiprotozoals for trematodes
Aka flukes
• praziquantel!
• albendazOle
Name 2 indications bezimidazoles ( eg mebendazole, albendazole )
• Hydatid disease (echinococcus tapeworm cestode), tinea solium
• many nematodes! (Roundworms)
Microsporidiosis
Ivermectin moa?
Immobilise tapeworm onochocerca volvulus by causing tonic paralysis of peripheral muscle system.
By potentiating GABA at cestode ‘s neuromuscular junction.
Ivermectin indications? (2)
• Drug of choice for onochocerca volvulus which causes river blindness
• most effective for strongyloïdes
Also filariasis, some gi helminth infections, ectoparasites (head lice and scabies)
Preferred: moxidectin (related)
Name 3 adverse effects ivermectin and moxidectin
• ocular irritation
. Transient ECG changes
• mazzotti reaction: severe immediate immune reaction to dead microfilariae
Somnolence
Diethylcarbamezine indications?
Drug of choice for lymphatic fibrosis caused by wucheria Bancrofti, loa loa and brugia malayia (all are filarioidea tissue species nematodes)
Praziquantel indications (4)
• Drug of choice all schistosome infections (blood flukes trematodes !)
• Drug of choice for cysticercosis (rare cystode condition caused by encystation of larvae of tapeworm Taenia solium in human organs)
. Other cestodes
. Chlonorchiasis ( trematode)
Not fasciola hepatica- one of few flukes treatment failure
Indications niclosamide?
Tapeworms (cestodes)
Name 5 classes drugs with examples for the treatment of malaria (sporozoa)
- quinolines: quinine, mefloquine, primaquine, chloroquine, amodiaquine
- Halofantrine (mdr)
- naphthoquinone: atovaquone
- endoperoxides: artemisin, artemether, artesunate
- antifolates: proguanil, pyrimethamine, sulfadoxine
Name 4 drugs for the treatment of non-malaria sporozoa: eg toxoplasmosis, cryptosporidia
- Pyrimethamine (anti folate)
- sulphonamide
- spiramycin
- atovaquine
Name 2 antiprotozoan drugs for the treatment of rhizopods
Eg entamoeba
. Metronidazole
• diloxanide
Name 5 antiprotozoan drugs for the treatment of flagellates
Eg trichomonas vaginalis • melarspoprol • nifurtimox • allopurinol • pentamide • amphotericin B • Ketoconazole, itraconanzole • paramomycin • metronidazole
What causes resistance of plasmodium to the antimalarials?
Target mutations
Moa quinolone’s?
Inhibition heme detoxification
Indication chloroquine?
Prophylaxis and treatment of all non-falciparum malaria first line.
Safe in pregnancy
Indication quinine?
Acute clinical attack falciparum malaria resistant to chloroquine.
Indication mefloquine?
All species uncomplicated malaria treatment (with artesunate) or prophylaxis
Name 3 antimalarial antifolates
- Pyrimethamine
- proguanil
- sulfadoxine
Moa antimalarial antifolates?
Slow acting blood and tissue schizonticides and sporonticides.
Inhibit formation folate compounds, thus inhibit DNA synthesis and cell division. All growing stages are affected.
Indications antifolates malaria? (3)
- Sulfadoxine pyrimethamine given together, with amodiaquine, for seasonal prophylaxis children
- Sulfadoxine pyrimethamine given together to treat malaria pregnant women and children
- acute uncomplicated malaria in combination with artesunate
Primaquine indication?
Radical cure of relapsing malarias: p.ovale, P. Vivax
Moa artemisinin, arsenate, artemether?
Generate free radicals, reactive species and alkylation parasite target biomolecules
Blood schizontocide, including MDR p falciparum
Indications artemisinin, arsenate, artemether?
- Uncomplicated p falciparum
- Mdr pf
- combination with other drugs to prevent drug resistance
Nitroimidazoles anti-protozoal indications? (3)
- Trichomoniasis
- invasive amebiasis
- giardiasis
Beznidazole indication?
Chagas disease: American trypanosomiasis
Fexinidazole indication?
First line oral African trypanosomiasis (trypanosoma Brucei gambiense)
Miltefosine indication? (2)
Visceral and cutaneous
• leishmaniasis
• amoebic encephalitis
Name 3 drugs with activity against both HIV and hep B
• Tenofovir
• emtricitabine
• lamivudine
All are nrti
Ribavirin indication?
(Nucleoside analogue )
• severe RSV bronchiolitis infants
• Lassa fever
• chronic hepatitis c
Treatment of choice for malaria in pregnancy, non-severe?
Oral quinine and clindamycin
Which species of candida is fluconazole inactive against?
C krusei
Name 4 adverse effects chloroQuine
• Neuropsychiatric
• blurred vision
. ECG changes
. Git symptoms
What is cinchonism and what causes it? (5)
Quinine toxicity dose too high. Signs: • thrombocytopenia • hypoglycaemia . Haemolysis • agranulocytosis
