Antivirals Flashcards
Aciclover
Guanine nucleoside analog - DNA polymerase inhibitor
Prodrug (phosphorylated by viral thymidine kinase & further phosphorylated to triphosphate by cellular enzymes)
Notes - Used for HSV1&2 > V2V > CMV > EBV. Used topically prophylactically for non-life threatening HSV infections. SE - local irritation, funny taste. Used orally for genital herpes or HSV1 if frequent episodes recurrence >6/year but S.E of nausea, diarrhea, headache. Used IV for severe infection but S.E of rashes emesis, hypotension, nephrotoxicity @ high dose so patient should drink lots of water to flush kidneys.
Valaciclovir
Guanine nucleoside analog - DNA polymerase inhibitor
Prodrug of aciclovir cleaved in GI tract. Longer duraction of action
Notes - better oral bioavailability but more expensive. Used for HSV1&2
kids
Valganciclovir
Guanine nucleoside analog - DNA polymerase inhibitor
Prodrug of ganciclovir
Notes - used for CMV retinitis in immunocompromised patients. SE - hematological issues - neutropenia, thrombocytopenia, anemia & teratogenicity, nausea, vomiting
Penciclovir
Guanine nucleoside analog - DNA polymerase inhibitor
Similar to aciclovir but active triphosphorylated form has longer half life (phosphorylated by viral thymidine kinase & further phosphorylated to triphosphate by cellular enzymes)
Use similar to aciclovir - topical Herpes
adults
Famciclovir
Guanine nucleoside analog - DNA polymerase inhibitor
Prodrug of penciclovir
Notes - better bioavailability. Used for Herpes zoster - shingles but SE - stomach upset, headache, fever
Cidofovir
DNA polymerase inhibitor - non-nucleoside analog
Notes - Prodrug, monophosphate nucleoside of cytosine. Made into into its active form by CELLULAR not viral thymidine kinase
Used for CMV retinitis if ganciclovir fails. Used IV & topical and always given with probenecid bc alone its extremely nephrotoxic (probenecid protects kidney by blocking tubular secretion)
Foscarnet
DNA polymerase inhibitor
Inhibitor of all DNA polymerase & RT
Not prodrug- doesn’t need phosphorylation
Notes - inhibits pyrophosphate exchange from dNTP by binding DNA polymerase or RT during replication. Used for HSV, V2V, HIV, CMV only administered I.V. SE- nephrotoxicity, neurotoxicity, hypocalcemia, hypomagnesemia, anemia
Zidovudine
NsRTI - requires triP
Notes - Prodrug, analog of thymidine. SE- anemia and other shared S.E of NsRTI - affect CNS (neurotoxicity, headache, insomnia, dizziness), lipodystrophy & ANEMIA
Didanosine
NsRTI - requires triP
Notes - Prodrug, analog of deoxyadenosine. Shared S.E of NsRTI that affect CNS (neurotoxicity, headache, insomnia, dizziness), lipodystrophy
Zalcitabine
NsRTI - requires triP
Notes- Prodrug, analog of cytosine. Shared S.E of NsRTI that affect CNS (neurotoxicity, headache, insomnia, dizziness), lipodystrophy
Iamivudine
NsRTI - requires triP
Notes - Prodrug, analog of cytidine. Shared S.E of NsRTI that affect CNS (neurotoxicity, headache, insomnia, dizziness), lipodystrophy
Tenofovir
NtRTI - requires diP
& nevirapine
Efavirenz
NNRTI
Notes - not prodrug - does not require P, non competitive inhibitor of RT. SE neurocognitive impairment, teratogenicity, hepatotoxicity, + SE of NsRTIs
Rotanavir
Protease inhibitor
Notes - prevent cleavage of large immature viral polyproteins which stops replication bc they are too large to package. Used to boost levels of other medications. One of the most potent CYP inhibitor. SE GI disturbance, CNS, atherosclerosis, blood disorders, hyperglycemia, dyslipidemia
Enfurvitide
Fusion inhibitor
Notes - binds gp41 and prevents it binding to host cell aka. prevents infection, specifically adsorption of the viral replication cycle. SE- flu symptoms, CNS effects, GI disturbances, hypersensitivity reactions
Maraviroc
Co-Receptor Inhibitor (CRI)
Notes - CCR5 antagonist (only works for this serotype of HIV). Blocks binding of gp120 to CCR5 and prevents membrane fusion - prevents infection! WARNING hepatotoxicity & some people can have allergic reactions.
Raltegravir
Integrase inhibitor (INI)
Notes - prevent 3’ processing and strand transfer to nucleus. SE- nausea, hyperglycemia, Stevens Johnson syndrome (skin and mucosal membrane problems), hepatotoxicity
Amentadine/Rimantadine
M2 inhibitors
Notes - inhibit viral uncoating by inhibiting M2 channels which prevents ion flux. Used for Influenza A only (benefit within 36-48h) and given orally. SE- GI toxicity & CNS toxicity in elderly. Should be cautious with elderly
Oseltamivir
Neuraminidase inhibitor
Notes - prevent release of new virions by preventing neuraminidase from cleaving receptor that detaches virion form host so the virus can’t infect neighbouring cells. It is ORALLY administered and activated by liver enzymes to oseltamivir carboxylase. Used for Influenza A & B. Also used for H1N1.
Zanamivir
Neuraminidase inhibitor
Notes - prevent release of new virions by preventing neuraminidase from cleaving receptor that detaches virion form host so the virus can’t infect neighbouring cells. It is INHALED. Used when resistance to oseltamivir. Used for Influenza A & B. Also used for H1N1.
How to treat HIV
HART
2 nucleoside analogs + PI
2 nucleoside analogs + NNRTi
Interferon alpha
leukocyte modulation
Used for treatment of chronic hep B & C, Hairy cell leukemia, Kaposi’s sarcoma
Parenteral administration
Interferon beta
fibroblast modification
Used to treat MS
Interferon gamma
T and NK modification
Used to treat chronic granulomatous disease & Hodgkins lymphoma
