T2ii: Describe the pharmacology of antiviral agents
Drug
MoA
Acivlovir
Inhibits viral DNA polymerase
Incorporates into and terminates the growing viral DNA chane
Oseltamivir
Reversible inhibitor of neuraminidase
Virion release from infected cells then spread to resp tract are inhibited bc this enzyme is blocked
Dose
Acivlovir
10mg/kg tds
Oseltamivir
75mg bd po
Spectrum
Acivlovir
Anti-HSV (herpes viruses)
Oseltamivir
Influenza
Indications
Acivlovir
Herpes
Oseltamivir
Influenza
PK
Acivlovir
A
Slow and poor OBA
D
Widely distributed
Low PPB <10%
M
E
Renal excretion
Oseltamivir
A
Prodrug has good 80% OBA (Oseltamivir-phosphate)
D
Prodrug has good 80% OBA (Oseltamivir-phosphate)
M
Rapid extensive de-esterefication and conversion to O-carboxylate by liver
E
O-carboxylate elimin by glom filtration
AE
Acivlovir
Rash
GI upset
Hepatic & Renal impairment
Blood dyscrasias
Oseltamivir
GI upset – nausea, vom
Headache
Skin rashes
Resistance
Acivlovir
Mutations
Oseltamivir
Monitoring
Acivlovir
LFT, renal fn