T3-L2: Antivirals Flashcards
What is viral infections can lead to a non-vesicular rash?
Non-Vesicular rash - measles, rubella, parvovirus, adenovirus and HHV6.
Vesicular rash: Chicken pox, HSV (1 and 2) and enteroviruses.
Vesicular rashes - start off as the non-vesicular - red, raised etc. And turn fluid filled.
Give examples of viral respiratory syndromes.
- Influenza A/B
- Respiratory Syncytial Virus
- Parainfluenza virus
- Human Metapneumovirus
- Rhinovirus
- Coronavirus (including SARS)
Give examples of viral gastroenteritis syndromes.
• Rotavirus - used to affect young children but there is an infection now
• Norovirus - affects all ages in all countries
• Astrovirus
• Sapovirus
• Adenovirus (group F)
Usually cause acute onset disease.- last a few days or a week. If severe can lead to dehydration.
Give examples of viral neurological syndromes.
Viruses can cause sere neurological disease such as encephalitis and meningitis.
Encephalitis - cause severe disease such as destruction of a lobe. This can result in death or severe problems.
Meningitis - tends to be self-limiting characterised by headaches, neck pain, fever etc.
• HSV - type 2 (more often cause of genital herpes) can cause a meningitis whereas type 1 (most causes of cold sores) causes an encephalitis
• Enteroviruses - can cause a meningitis
• Rabies
• Japanese encephalitis virus
• Nipah Virus
Give examples of viral blood borne syndromes.
• Hepatitis viruses - HBV - HCV • Retroviruses - HIV 1,2 - HTLV 1,2 (human T-cell lymphotropic virus type 1)
When are antivirals used?
- In acute infections in the general population where there is a high risk of complications.
- Chronic infections such as HIV, HBC and HCV
- Infections in immunocompromised such as post transplant, those with immunosuppressive therapies and patients with primary immunodeficiencies.
What anti-viral is used to treat HSV?
Aciclovir. It is used to treat invasive disease such as encephalitis and disseminated HSV (the immunocompromised and neonates). It is used in primary oral-labial or genital herpes. It can be used as a prophylactic treatment in frequent disruptive reactivations.
What anti-virals is used to treat VZV?
Aciclovir can also be used to treat VSV - chick pox or shingles. Needs a higher dose. The older you get the more severe it is.
Treatment of shingles:
- Used based on age - definitely used in patients over 50/60 as it can reduce the include of post-hepatic neuralgia.
- If shingles involves the eye, you treat anyone at any age.
- Also those who are immunocompromised are treated.
What antiviral is used in the treatment of influenza?
Neuraminidase inhibitors such as oseltamivir (oral) and zanamavir (inhaled).
It is usually a self-limiting virus. Need to be given in the first few days. There is no benefit in giving treatment after as the immune system comes through.
Treatment is given to high risk patients without a time limit. These people normally get the vaccine in the autumn:
• Chronic neurological, hepatic, renal, pulmonary and chronic cardiac disease
• Diabetes mellitus
• Severe immunosuppression
• Age over 65 years
• Pregnancy (including up to two weeks post partum)
• Children under six months of age
• Morbid obesity (BMI ≥40)
How does azidothymidine work?
It is an NRTI - Nucleoside Reverse Transcriptase Inhibitor (NRTI).
AZA works by inhibiting reverse transcriptase of HIV.
Give examples of HIV NRTIs.
NRTI - Nucleoside Reverse Transcriptase Inhibitor (NRTI).
• Pyrimidine analogues ○ Thymidine analogues - not used as much - such as Zidovudine ○ Cytosine analogues - has low side effects and is potent - example includes Lamivudine - has a low genetic barrier to resistance and after a few years Hep B becomes resistant so not used in that treatment • Purine analogues (Adenosine and Guanosine) □ Abacavir □ Tenofovir - can be treat someone with chronic HBV
What is used in the treatment of HBV?
Some NRTIs also active against HBV
- Lamividine
- Tenofovir
What is Sofosbuvir used for?
Hepatitis C. It is an RNA polymerase nucleotide inhibitor.
What is Efavirenz and Nevirapine to treat?
HIV (and those with HIV combined with TB)
Give examples of protease inhibitors.
Used in HIV:
• Atazanavir
• Darunavir - very potent -HIV drug used
• Ritonavir* - at a low concentration can reduce the concentration of the other drugs and so can act as a boosting agent now
Used in HCV:
• Paritaprevir
• Grazoprevir
Viruses often use host protease or encode unique protease. When they make there on polyproteins they snip it uses there own proteases. This is required for viral function. Since only used buy viruses they are a good target.
