L35- Antiviral Drugs Flashcards
besides HIV and its associated HAART, list the common viral infections where antiviral therapy is employed
1) Respiratory Viruses: influenza A/B (+ RSV)
2) Hepatitis: B, C
3) Herpes: 1/2, 5 (CMV)
list the drugs for respiratory viral infections
- neuraminidase inhibitors
- endonuclease inhibitors
- synthetic guanosine analog
previously adamantanes
(1) are anti-viral drugs previous drugs used to treat respiratory viral infections- include agents. (2) was the primary clinical use, with (3) mechanism. (4) was the main reason that prompted its discontinued use. (5) are the AEs for (1).
1- Adamantanes: amantadine, rimantadine
2- influenza A Tx and prevention
3- prevents uncoating of viral binding
4- high rates of resistance
5- GI upset, nervousness, light-headedness, insomnia, anorexia, nausea, livedo reticularis
In the release of virons from infected cells, (1) on the virus is bound to (2) on the cell surface. (3) is then used to cleave this interaction, specifically (2) in order to release the virus. (4) have a (5) shape in order to prevent the release of viruses from infected cells.
1- hemagglutinin
2- sialic acid receptor
3- neuraminidase
4- neuraminidase inhibitors
5- sialic acid analog or substrate for neuraminidase (to block enzymatic function)
list the neuraminidase inhibitors
peramivir (IV)
oseltamivir (oral)
zanamivir (intranasal)
neuraminidase inhibitors:
- used to treat and prevent (1)
- best for treatment if given in (2) time-frame in order to have (3) effects
1- influenza A, B (prophylaxis and Tx)
2- first 24-48hrs of Sxs
3- shorten illness duration
______ is the IV neuraminidase, include AEs
peramivir:
- pruritus, skin peeling
- myalgia, fever, chills
- cough
- GI discomfort
______ is the oral neuraminidase, include AEs
oseltamivir:
-GI upset —- take with meals
______ is the intranasal neuraminidase, include AEs
zanamivir:
-airway irritation
Endonuclease inhibitors:
- functions in order to prevent (1)
- (2) clinical uses (include restriction)
- (3) AEs
Baloxavir Marboxil
1- viral gene transcription
2- prevents and treats influenza A, B
3- diarrhea, bronchitis
list the endonuclease inhibitors and describe its mechanism
Baloxavir Marboxil:
- prodrug is hydrolized into baloxavir
- -> inhibits endonuclease via selective binding of polymerase acidic protein (PA), which is required for gene transcription
list the guanosine analogs and describe its mechanism
Ribavirin, converted to ribavirin-triphosphate:
-inhibits RNA-dep. RNA poly –> inhibition of viral synthesis
-inhibits guanosine triphosphate formation + prevents viral mRNA capping
Guanosine Analogs:
- (1) are the clinical uses
- (2) is the route of administration
- (3) briefly describe distribution issue
(ribavirin)
1- influenza A/B, parainfluenza, *RSV, *HCV, lassa fever
2- IV, oral, aerosolized
3- prolonged in RBCs, 16-40 days (intracellular sequestering)
list the AEs and contraindications for guanosine analogs
(ribavirin)
- hemolytic anemia (10-20%)
- fatigue
- CNS: HA, insomnia
- GI: nausea, anorexia
Contraindications: pregnancy or males with pregnant partners
list the drugs for Hepatitis B infections
Interferon (α)
Nucleo-side/tide analogs
describe the mechanism of Interferon in the treatment of HBV and HCV
i) IFN binds receptor
ii) induces PKR (protein kinase R)
iii) induction of specific protein synthesis
iv) specific proteins inhibit RNA and DNA synthesis
list all the uses of IFN-α
-chronic HBV, HCV, in combination with ribavirin (guanosine analog)
- condyloma acuminata
- hairy cell leukemia
- Kaposi’s sarcoma
- renal cell carcinoma
- malignant melanoma
IFN-β is used clinically to treat (1)
IFN-γ is used clinically to treat (2)
β- MS
γ- chronic granulomatous disease
IFN-α AEs
- flu-like Sxs: fever, chills, myalgia, GI disturbances
- fatigue
- depression
-Neutropenia —- potentiated if given with Zidovudine
IFN-α:
- (1) is the main form of administration via (2) route
- (3) route of elimination
- (4) may accumulate
1- pegylated (attaches polyethylene glycol – improves F, given once a week)
2- IV, SQ, intralesional
3- liver and kidneys
4- theophylline