Podcast Beta
Questions and Answers
What is the mechanism of action of Oseltamivir and Zanamivir?
What is the route of administration for Zanamivir?
What is the common adverse effect of Oseltamivir?
What is the duration of treatment with Oseltamivir?
Signup and view all the answers
Which antiviral drugs are active against Influenza A and B viruses?
Signup and view all the answers
What is the mechanism of action of Adamantane antivirals?
Signup and view all the answers
Why are Adamantane antivirals no longer recommended?
Signup and view all the answers
What is the administration route of zidovudine?
Signup and view all the answers
How are Oseltamivir and Zanamivir excreted?
Signup and view all the answers
What is the elimination pathway of abacavir?
Signup and view all the answers
What is a common adverse effect of NRTIs?
Signup and view all the answers
What is a known hypersensitivity reaction to abacavir?
Signup and view all the answers
What is the mechanism of resistance to NRTIs?
Signup and view all the answers
What is a characteristic of cross-resistance between NRTIs?
Signup and view all the answers
What is a characteristic of NRTIs?
Signup and view all the answers
What is the classification of NNRTIs?
Signup and view all the answers
What is the mechanism of action of acyclovir?
Signup and view all the answers
What is the bioavailability of oral acyclovir?
Signup and view all the answers
What is the primary route of excretion for acyclovir and its metabolites?
Signup and view all the answers
What is the concentration of acyclovir in the cerebrospinal fluid (CSF) compared to serum values?
Signup and view all the answers
What is the most effective route of administration for treating herpes simplex encephalitis?
Signup and view all the answers
What is the benefit of topical acyclovir in treating recurrent genital herpes?
Signup and view all the answers
What is the characteristic of an asymptomatic intestinal infection in amebiasis?
Signup and view all the answers
What is the contraindication of diloxanide furoate?
Signup and view all the answers
What is the main route of excretion of iodoquinol?
Signup and view all the answers
What is the class of antibiotic that paromomycin sulfate belongs to?
Signup and view all the answers
What is the site of action of paromomycin sulfate?
Signup and view all the answers
What is the main adverse effect of iodoquinol?
Signup and view all the answers
What is the mechanism of action of enfuvirtide?
Signup and view all the answers
What is the route of administration of enfuvirtide?
Signup and view all the answers
What is the mechanism of action of maraviroc?
Signup and view all the answers
What is a common adverse effect of maraviroc?
Signup and view all the answers
What is the mechanism of action of integrase inhibitors?
Signup and view all the answers
What are common adverse effects of integrase inhibitors?
Signup and view all the answers
What is the role of ritonavir and cobicistat in HIV treatment?
Signup and view all the answers
What is the class of antiviral drugs that enfuvirtide belongs to?
Signup and view all the answers
Study Notes
Antiviral Drugs
- Oseltamivir and Zanamivir:
- No interference with vaccines
- Active against Influenza A and B viruses
- Administered prior to exposure or within 48 hours after onset of symptoms
- 5-day course
- MOA: Selectively inhibit neuraminidase, preventing the release of new virions
- PK: Oseltamivir is a prodrug, administered orally, and activated by hepatic esterases; Zanamivir is active, administered via inhalation; both are excreted in the urine
- Adverse effects: Oseltamivir - nausea and vomiting (minimized with food), headache; Zanamivir - respiratory discomfort; caution in patients with airway diseases
- Resistance: Mutations of the neuraminidase enzyme
Antiviral Drugs
- Adamantane antivirals (e.g. Amantadine and Rimantadine):
- Active against Influenza A viruses only
- Administered prior to exposure or within 48 hours after onset of symptoms
- Due to high resistance, no longer recommended
- MOA: Block M2 proton ion channel, blocking viral uncoating
- PK: Amantadine is excreted unchanged in the urine; Rimantadine is extensively metabolized before urinary excretion
- Use of Amantadine in Parkinson's disease
Antiviral Drugs
- Acyclovir:
- MOA: Inhibits viral DNA synthesis
- PK: Oral, IV, and topical administration; partially metabolized to an inactive drug; drug and metabolites excreted in the urine
- Oral acyclovir has low bioavailability (15-20%); absorption is not affected by food; no systemic concentrations are detected by the topical route
- Diffuses readily into most tissues and body fluids (20-50% of serum values inside CSF)
- IV: Used for herpes simplex encephalitis, neonatal HSV infections, and serious HSV or VZV infections
- Topical: Used for cold sores, genital herpes, and ophthalmic; no benefit in treating recurrent genital herpes
Antiviral Drugs
- NRTIs:
- PK: Administered orally (zidovudine available also as IV); renally excreted (except abacavir, which is hepatically eliminated)
- Adverse effects: Toxicities due to inhibition of mitochondrial DNA polymerase gamma; lactic acidosis with hepatic steatosis, lipodystrophy
- Abacavir: Hypersensitivity (fever, fatigue, rash, GI disturbances, respiratory distress)
- Resistance: Alterations of viral RT; cross-resistance occurs between agents of the same analog class
Antiviral Drugs
- NNRTIs:
- Boosters: Ritonavir and cobicistat
Antiviral Drugs
- Entry Inhibitors:
- Enfuvirtide: Fusion inhibitor; polypeptide that binds to viral gp41 required for entry into CD4 cells; administered via SC injection; causes pain, erythema, induration, and nodules
- Maraviroc: Entry inhibitor; blocks the CCR5 coreceptor that works with viral gp41 to facilitate HIV entry; hepatotoxic
Antiviral Drugs
- Integrase Inhibitors:
- Examples: Raltegravir, elvitegravir, dolutegravir, and bictegravir
- Inhibits the insertion of proviral DNA into the host cell genome
- Adverse effects: Nausea, diarrhea
Antiprotozoal Drugs
- Amebiasis:
- Diloxanide furoate: Not used in pregnancy; adverse effects: flatulence (common), nausea, and abdominal cramps (infrequent), rashes (rare)
- Iodoquinol: Active against luminal cysts and trophozoites; 90% retained in the intestine; excreted in feces; remainder is absorbed, glucuronidated, and excreted in the urine
- Adverse effects: Diarrhea, anorexia, nausea, vomiting, abdominal pain, headache, rash, and pruritus
- Paromomycin sulfate: Aminoglycoside antibiotic; active against luminal forms of Entamoeba histolytica; not significantly absorbed; small amount absorbed is excreted unchanged in urine
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Description
This quiz covers the mechanisms, administration, and adverse effects of Oseltamivir and Zanamivir, antiviral drugs used to treat Influenza A and B viruses.
