Infectious Diseases - Antivirals Flashcards
What does aciclovir do?
What is it active against?
How do viruses become resistant?
What significant adverse effects?
Guanosine analogue activated by viral thymidine kinase to inhibit viral DNA polymerase
Active against: HSV, VZV and some CMV
Mechanisms of Resistance:
- deficient viral TK
- mutations to viral TK
- Mutations to DNA polymerase
S/E:
- crystalline nephropathy
What does ganciclovir do?
What is it active against?
What significant adverse effects?
Guanosine analogue activated by viral thymidine kinase to inhibit viral DNA polymerase
Active against: CMV
(also against HSV1/2, VZV, EBV and HHV6)
Preferentially phosphorylated by CMV viral kinase UL97
S/E:
- myelosuppression
- agranulocytosis
What is the bioavailability of aciclovir, ganciclovir and valganciclovir?
Aciclovir: 20%
Ganciclovir 10%
Valganciclovir 60%
Where is there good evidence for valganciclovir?
Efficacy in HIV retinitis and CMV retinitis
NONINFERIOR to ganciclovir but NOT in severe disease
What does ribavirin do?
What is it active against?
What significant adverse effects?
Guanosine analogue that inhibits monophosphate (IMP) dehydrogenase –> interferes with viral capping of mRNA
Active against: chronic Hep C and RSV
S/E
- haemolytic anaemia
What does amantadine do?
What is it active against?
What significant adverse effects?
Inhibits uncoating of virus in cell
Also releases dopamine from nerve endings
Active against:
- influenza
- also used in parkinsons
S/E
- confusion
- ataxia
- slurred speech
What does oseltamivir do?
What is it active against?
Inhibits neuraminidase
Used in influenza
What does Foscarnet do?
What is it active against?
What significant adverse effects?
Pyrophosphate analogue that directly inhibits pyrophosphate binding site of viral DNA polymerase
Activity against:
CMV
HSV if not responding to aciclovir
Also: VZV, hep B
S/E
- Nephrotoxicity
- Hypocalcaemia
- Hypomagnesaemia
- Seizures
What does Cidofovir do?
What is it active against?
What significant adverse effects?
Nucleotide analogue of deoxycytidine monophosphate dCMP
INDEPENDENT of any need to be activated by viral enzymes
Active against:
- CMV retinitis in HIV
also: other herpesviruses, adenovirus and polyomavirus
S/E:
nephrotoxicity
What does BRINCIDOFOVIR do?
Prodrug of cidofovir which is a nucleotide analogue of deoxycytidine monophosphate dCMP
Active against: CMV, adenovirus, BK and HSV
Prevents CMV events in alloHSCT patients
