Antiviral Agents for Influenza A

Questions and Answers

What is the primary therapeutic action of Rimantadine?

Inhibits viral DNA replication

Prevents the uncoating of the virus (correct)

Acts as an antibiotic against bacterial infections

Stimulates the immune response

Which condition is contraindicated for the use of Rimantadine?

Asthma

Renal disease

Acute viral infections

Pregnancy and lactation (correct)

What is the elimination half-life (HL) of Rimantadine?

1.5-2 hours

Unknown duration

2.5-5 hours

25.4 hours (correct)

Which adverse effect is associated with Acyclovir?

Vertigo Signup and view all the answers

What is a potential drug interaction concern when using Acyclovir?

Increased nephrotoxicity with other nephrotoxic drugs Signup and view all the answers

What is the primary therapeutic action of fosamprenavir?

Inhibition of protease activity Signup and view all the answers

What is a major indication for using fosamprenavir?

Management of adults with symptomatic HIV infection Signup and view all the answers

What should be considered when prescribing fosamprenavir to a pregnant woman?

Its use should be determined by weighing benefits against risks Signup and view all the answers

What is the peak time for fosamprenavir after oral administration?

1.5 to 4 minutes Signup and view all the answers

What is the primary therapeutic action of enfuvirtide?

Blocking HIV-1 from entering healthy cells Signup and view all the answers

For which patients is enfuvirtide indicated?

Patients with clinical or immunological deterioration after other treatments Signup and view all the answers

Which of the following is a caution when prescribing enfuvirtide?

Use caution in patients with lung disease or pregnancy Signup and view all the answers

What is a common adverse effect of fosamprenavir?

Skin rash Signup and view all the answers

What is the primary therapeutic action of Nevirapine?

Blocks replication of HIV by changing the structure of HIV enzyme Signup and view all the answers

Which of the following is a contraindication for Zidovudine?

Bone marrow suppression Signup and view all the answers

What is the peak time for the pharmacokinetics of Nevirapine?

4 hours Signup and view all the answers

Which adverse effect is common with Zidovudine treatment?

Bone marrow suppression Signup and view all the answers

In which scenario should Nevirapine be used with caution?

HIV-infected women breastfeeding Signup and view all the answers

What is the half-life of Nevirapine?

45 hours Signup and view all the answers

Which drug interaction should be avoided in patients taking Nevirapine?

Hormonal contraceptives Signup and view all the answers

What is the therapeutic action of Zidovudine?

Inhibits replication of various retroviruses like HIV Signup and view all the answers

What is the primary therapeutic action of Adefovir in treating chronic hepatitis B?

Inhibits reverse transcriptase, causing DNA chain termination Signup and view all the answers

In which situation is Adefovir contraindicated?

During pregnancy and with known allergies Signup and view all the answers

What side effect is associated with the use of Adefovir?

Severe to fatal hepatomegaly with steatosis Signup and view all the answers

What is the primary mechanism of action for Simeprevir in treating chronic hepatitis C?

Inhibits hepatitis C protease formation Signup and view all the answers

Under what condition should caution be applied when using Simeprevir?

Severe liver disease Signup and view all the answers

Which of the following is a common adverse effect of Simeprevir?

Fatigue Signup and view all the answers

What is a significant drug interaction concern when using Adefovir?

Increased risk of renal toxicity with nephrotoxic drugs Signup and view all the answers

What should be avoided when using Simeprevir to maintain its effectiveness?

St. John's wort Signup and view all the answers

What is the main therapeutic action of Maraviroc?

Binds to CCR5 to prevent HIV-1 entry into the cell Signup and view all the answers

Which populations should avoid using Maraviroc due to contraindications?

Patients with hypersensitivity and nursing mothers Signup and view all the answers

What is a significant adverse effect of Maraviroc?

Severe hepatotoxicity Signup and view all the answers

What should be monitored when administering Raltegravir along with rifampin?

Serum levels of Raltegravir Signup and view all the answers

What is the pharmacokinetic profile of Maraviroc regarding its half-life?

14-28 hours Signup and view all the answers

How does Raltegravir function therapeutically?

It inhibits the integrase enzyme to prevent provirus formation Signup and view all the answers

What should be considered when prescribing Raltegravir for patients at risk for rhabdomyolysis?

Strict adherence to dosage is required Signup and view all the answers

Which of the following is a common adverse effect of Raltegravir?

Headache and dizziness Signup and view all the answers

Study Notes

Antiviral Agents Overview

Antiviral agents like Rimantadine, Acyclovir, Nevirapine, Zidovudine, Fosamprenavir, Enfuvirtide, Maraviroc, Raltegravir, Adefovir, and Simeprevir target various viral infections, primarily influenza, herpes, and HIV.

Rimantadine

Therapeutic action: Inhibits viral replication by preventing virus uncoating.
Indicated for prophylaxis and treatment of influenza A in adults and children.
Pharmacokinetics: Oral administration, slow onset, peak effect at 6 hours, half-life of 25.4 hours; excreted unchanged in urine.
Contraindications: Embryotoxic; avoid during pregnancy and lactation.
Adverse effects: Light-headedness, dizziness, insomnia, nausea, and depression.
Drug interactions: Increases atropine-like effects with anticholinergics; may reduce effectiveness of aspirin and acetaminophen.

Acyclovir

Therapeutic action: Inhibits viral DNA replication with minimal impact on human cells.
Indications: Effective against herpes simplex, herpes zoster, and cytomegalovirus (CMV), especially in immunocompromised patients.
Pharmacokinetics: Oral (varying onset, peak in 1.5-2 hours), IV (immediate onset, peak in 1 hour), topical (not absorbed systemically), half-life of 2.5-5 hours; excreted unchanged in urine.
Contraindications: Use cautiously in pregnancy and lactation; caution in patients with allergies and renal disease.
Adverse effects: Headache, vertigo, nausea, vomiting, rash.
Drug interactions: Increased risk of nephrotoxicity with nephrotoxic drugs; drowsiness risk with zidovudine.

Nevirapine

Therapeutic action: Binds to HIV-1 reverse transcriptase, blocking replication.
Indications: For HIV-1 infected patients with clinical or immunological deterioration, used with other retrovirals.
Pharmacokinetics: Oral, rapid onset, peak in 4 hours, half-life of 45 hours; metabolized in liver, excreted in urine.
Contraindications: Limited pregnancy studies; not recommended for breastfeeding or children.
Adverse effects: Headache, nausea, liver dysfunction, rash.
Drug interactions: Avoid with hormonal contraceptives and protease inhibitors.

Zidovudine

Therapeutic action: Thymidine analogue that inhibits replication of retroviruses like HIV.
Indications: Managing symptomatic HIV infection in adults and preventing maternal-fetal transmission.
Pharmacokinetics: Oral (peak in 30-90 mins), IV (peak at infusion end), half-life of 30-60 mins; metabolized in liver, excreted in urine.
Contraindications: Only proven safe agent during pregnancy; caution in bone marrow suppression, hepatic/renal impairment.
Adverse effects: Headache, insomnia, diarrhea, bone marrow suppression.
Drug interactions: Severe drowsiness when combined with cyclosporine.

Fosamprenavir

Therapeutic action: Inhibits protease activity, resulting in noninfectious virus particles.
Indications: Managing symptomatic HIV infection in adults.
Pharmacokinetics: Oral, varying onset, peak in 1.5-4 hours, half-life of 7.7 hours; metabolized in liver, excreted in feces and urine.
Contraindications: Caution in pregnancy; avoid breastfeeding with HIV patients.
Adverse effects: Headache, mood changes, rash, potential for stevens-johnson syndrome.
Drug interactions: Increased risk of adverse effects if combined with ritonavir.

Enfuvirtide

Therapeutic action: Prevents HIV-1 entry into cells by inhibiting viral membrane fusion.
Indications: HIV-1 patients with clinical or immunological deterioration after other treatments.
Pharmacokinetics: Subcutaneous, slow onset; peak in 4-8 hours, half-life of 3.2-4.4 hours; metabolized in liver.
Contraindications: Hypersensitivity and nursing mothers; caution in lung disease or pregnancy.
Adverse effects: Insomnia, peripheral neuropathy, pneumonia.
Drug interactions: No reported interactions, but caution with other drugs.

Maraviroc

Therapeutic action: Binds to CCR5 on cell membranes, preventing HIV-1 entry.
Indications: Combination therapy for adults with CCR5 tropic HIV-1.
Pharmacokinetics: Oral, peak in 0.5-4 hours, half-life of 14-28 hours; metabolized in liver, excreted in feces and urine.
Contraindications: Hypersensitivity; not approved for children; caution in liver disease and pregnancy.
Adverse effects: Severe hepatotoxicity, dizziness, gastrointestinal symptoms.
Drug interactions: Increased toxicity with CYP3A inhibitors; decreased effectiveness with CYP3A inducers.

Raltegravir

Therapeutic action: Inhibits integrase, preventing HIV-1 provirus formation.
Indications: Patients with evidence of viral replication.
Pharmacokinetics: Oral, rapid onset, peak in 3 hours, half-life of 9 hours; metabolized in liver.
Contraindications: Hypersensitivity, not for initial treatment in adults or nursing mothers; caution for rhabdomyolysis risk.
Adverse effects: Headache, dizziness, muscle risks.
Drug interactions: Monitor if combined with rifampin; avoid St. John’s wort.

Adefovir

Therapeutic action: Inhibits reverse transcriptase in hepatitis B virus, leading to viral replication inhibition.
Indications: Chronic hepatitis B treatment in adults with active disease.
Pharmacokinetics: Oral, rapid onset, peak in 0.6-4 hours; half-life of 7.5 hours; excreted in urine.
Contraindications: Known allergies, lactation, caution in renal/liver impairment.
Adverse effects: Headache, nausea, potential hepatomegaly.
Drug interactions: Increased renal toxicity risk with other nephrotoxic drugs.

Simeprevir

Therapeutic action: Inhibits hepatitis C protease formation, preventing viral replication.
Indications: Chronic hepatitis C in adults with compensated liver dysfunction.
Pharmacokinetics: Oral, rapid onset, peak in 4-6 hours, half-life of 10-12 hours; excreted in feces.
Contraindications: Known allergies, pregnancy, caution in severe liver disease.
Adverse effects: Fatigue, gastrointestinal issues, rash.
Drug interactions: Caution with other protease inhibitors; avoid St. John's wort for efficacy.

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Description

This quiz covers antiviral agents, particularly focusing on Rimantadine, and its therapeutic actions against Influenza A. You will learn about its pharmacokinetics, indications for use, and important contraindications. Suitable for both students and healthcare professionals interested in virology and pharmacology.