Week 10 - Nucleoside Analogues, Antivirals for Hep C, and Influenza Flashcards
Nucleoside analogues: examples
Acyclovir, famciclovir, valacyclovir
Nucleoside analogues (-cyclovir): MOA
Interferes with DNA synthesis and inhibits viral replication
Nucleoside analogues (-cyclovir): ADR
HA, N/V, skin rash, elevated transaminases, nasopharyngitis, fatigue, depression
Nucleoside analogues (-cyclovir): caution and contraindications
- Caution in renal impairment
- Acyclovir recommended in pregnancy, lactation, pediatrics >2 years
HCV meds
Ledipasvir/Sofosbuvir, sofosbuvir/velpatasvir
Prescribed by hepatologist
HCV: MOA
Inhibits HCV protein necessary for viral replication
Tx based on genotype and stage of disease
HCV: ADR
HA, fatigue, N/D, myalgias, pruritus
HCV: caution and contraindications
- BLACK BOX: hep B virus reactivation
- Avoid in pregnancy; limited data in lactation
Influenza: examples
Oseltamivir (Tamiflu), Zanamivir (Relenza), Peramivir (Rapivab), Baloxavir marboxil
Oseltamivir, Zanamivir, Peramivir: classification
Neuraminidase inhibitor
Neuraminidase inhibitors: MOA
Neuraminidase is a viral enzyme responsible for cleaving viral attachment to the host cell surface, allowing for viral circulation
Inhibiting this enzyme prevents release of virus and halts spreading of infection
Effective against influenza A and B
Neuraminidase inhibitors: caution and contraindications
- Caution in pregnancy (Tamiflu recommended in lactation)
- Caution in renal and hepatic impairment
- Avoid Zanamivir w/ hx of respiratory disease
Neuraminidase inhibitors: ADR
HA, N/V
Rare: anaphylaxis, neuropsychiatric events
Baloxavir marboxil: MOA
Dependent endonuclease inhibitor that interferes w/ viral RNA transcription –> inhibition of influenza virus replication
Baloxavir marboxil: ADR
Diarrhea, nasopharyngitis
Baloxavir marboxil: caution and contraindications
- Other agents recommended in pregnancy and lactation
- Avoid in pregnancy <12 years
Nucleoside analogues (-cyclovir): indications
Herpes simplex (herpes labialis, herpes genitalis)
Acyclovir: indications
- Herpes simplex virus 1, 2, and 6
- Varicella zoster
- Epstein-Barr virus
- CMV
Valacyclovir: indications
Converted to acyclovir after PO administration –> active against same viruses
Famciclovir: indications
- HSV-1, HSV-2
- Varicella zoster
- Epstein-Barr virus
- Hep B
Ganciclovir: indications
CMV
Nucleoside analogues (-cyclovir): ADR
- Acyclovir/valacyclovir*: few ADRs when given PO
- Valacyclovir*: thrombocytopenia purpura, hemolytic uremic syndrome in immunocompromised patients
- Famciclovir*: HA
- Ganciclovir*: granulocytopenia, anemia, thrombocytopenia, may be carcinogenic
Nucleoside analogues (-cyclovir): patient education
- BUN and creatinine will be monitored
- Maintain adequate hydration
- Monitor for symptoms of renal failure, encephalopathic changes, blood dyscrasias
HCV: drug interactions
Co-administration of ledipasvir, sofosbuvir (Harvoni), and amiodarone can cause serious symptomatic bradycardia
True/False: Oseltamivir is a prodrug
True
Influenza (zanamivir): ADR
Bronchitis and SOB (bronchospasms)
Avoid in asthma/COPD