The document discusses various antiviral drugs used to treat viral infections. It begins by describing viruses and their replication cycles. It then classifies antiviral drugs based on their mechanisms of action and discusses individual drugs used to treat herpes viruses, influenza viruses, hepatitis viruses, cytomegalovirus, and more. Key drugs mentioned include acyclovir, valacyclovir, famciclovir for herpes, oseltamivir and zanamivir for influenza, and ganciclovir and valganciclovir for cytomegalovirus. The document provides details on the mechanisms, uses, and side effects of many commonly used antiviral medications.

1. Antiviral Drugs
Dr. Sneha Dange, Jr2
Dept. of Pharmacology,
GMC, Nagpur

2. Overveiw :
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Antiviral Drugs 2
Introduction
Types of viruses
Replicative cycle of virus
Classification of drugs
Individual drugs
Summary

3. Introduction :
◦ Virus is ultramicroscopic infectious parasite
◦ Consist of core genome of nucleic acid ( DNA or RNA), contained in
a protein shell (capsid) & this is surrounded by lipoprotein membrane
(envelope) – “Virion”
◦ Obligate parasites & are inactive outside the host cell
◦ Theses host cells may be mammals, insect or bacteria
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Antiviral Drugs 3

4. DNA Viruses
◦ Adenoviruses (URTI & eye infection)
◦ Hepadnaviruses (Hepatitis-B)
◦ Herpes viruses (HSV-1 oral/ocular herpes,
HSV-2 genital herpes, VZV- chicken pox,
CMV- infectious mononucleosis, EBV- B cell
lymphoma)
◦ Papilloma viruses (warts)
◦ Poxviruses (small pox)
◦ Parvoviruses (erythema infectiosum,
aplastic anaemia)
RNA viruses
◦ Picornaviruses (polio & hepato Hept-A)
◦ Orthomyxoviruses (influenza A,B,C )
◦ Paramyxoviruses ( rubulavirus-mumps,
morbillivirus-measles, RSV-LRTI )
◦ Rhabdoviruses (rabies)
◦ Arboviruses (Toga-chikungunya, flavivirus-
dengue, bunyavirus-encephalitis)
◦ Rotavirus (gastroenteritis in children )
◦ Retrovirus ( HIV )
◦ Arenavirus (viral meningitis)
◦ Coronavirus ( URTI )
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5. Replication of DNA virus :
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6. Replication of RNA virus :
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7. Classification of Antiviral drugs : (Mechanism based)
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DNA polymerase
inhibitors
Purine analogues
Acyclovir,
Valacyclovir,
Ganciclovir,
Valganciclovir,
Famciclovir,
Penciclovir,
Cidofovir,
Adefovir,
Entecavir,
Vidarabine,
Valomaciclovir
Pyrimidine
analogues
Idoxuridine,
Trifluridine,
Telbivudine
Non-
nucleoside
Foscarnet
m-RNA synthesis
inhibitors
Ribavirin,
Fomivirsen
Inhibitors of viral
penetration & uncoating
Amantadine,
Rimantadine,
Docosanol
Neuraminidase
inhibitors
Zanamivir,
Oseltamivir,
Peramivir,
Laninamivir
Immunomodulators
Interferons,
Palivizumab,
Imiquimod

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Classification of Antiviral drugs :
(Therapeutic)
Anti-Herpes
virus drugs
ldoxuridine
Trifluridine
Acyclovir
Val acyclovir
Famciclovir
Ganciclovir
Valganciclovir
Cidofovir
Foscarnet
Anti-Influenza
virus drugs
Amantadine
Rimantadine
Oseltamivir
Zanamivir
Peramivir
Anti-Hepatitis virus
drugs
For Hepatitis B
Lamivudine
Entecavir
Adefovir
dipivoxil
Tenofovir
Telbivudine
For Hepatitis C
Ribavirin
Interferon α
Sofosbuvir
Simeprevir
Daclatasvir
Ledipasvir
Velpatasvir

9. Anti-Herpes virus drugs
 Acyclovir –
An acyclic guanosine derivative
10 times more potent against HSV-1 & HSV-2 than VZV
converted first to the monophosphate derivative- virus specified thymidine
kinase & di- and triphosphate compounds - host cell enzymes
Oral bioavailability is low (15–20%) & is unaffected by food
Cleared through kidney & t1/2 is 2.5–3 hours
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Antiviral Drugs 9

10. Anti-Herpes virus drugs contd..
Uses :
◦ Intravenous acyclovir - treatment of choice for herpes simplex encephalitis,
neonatal HSV infection, and serious HSV or VZV infections
◦ Topical acyclovir cream is less effective than oral therapy for primary HSV
infection
◦ Neonates - oral acyclovir suppression for 6 months following acute treatment
improves neurodevelopmental outcomes
◦ In immunocompromised patients with VZV infection, IV acyclovir reduces the
incidence of cutaneous and visceral dissemination
◦ Resistance to acyclovir can develop in HSV or VZV through alteration in either
the viral thymidine kinase or the DNA polymerase
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Antiviral Drugs 10
Acyclovir –

11. Anti-Herpes virus drugs contd..
Adverse effects :
◦ Oral: drug is well tolerated but headache, nausea, malaise
◦ Intravenous:
Rashe , sweating, emesis and fall in BP occur
Dose-dependent decrease in g. f.r. is the most important toxicity
Reversible neurological manifestations (tremors, lethargy, disorientation,
hallucinations, convulsions and coma)
Not teratogenic
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Acyclovir –

12. Valacyclovir
◦ L-valyl ester of acyclovir
◦ Rapidly converted to acyclovir after first-
pass metabolism resulting in serum levels
that are 3-5 times greater than oral &
intravenous acyclovir
◦ Oral bioavailability is 54–70%
◦ Elimination half-life 2.5–3.3 hours
◦ Drug of choice in herpes zoster
Famciclovir
◦ Ester prodrug of penciclovir
◦ Needs viral thymidine kinase but does not
cause chain termination
◦ Penciclovir triphosphate has lower affinity but
achieves higher intracellular concentrations
◦ Bioavailability - 70%
◦ The intracellular half-life 7–20 hours
◦ Excreted in the urine
◦ Active against HSV-1, HSV-2, VZV, EBV, HBV
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Anti-Herpes virus drugs contd..

13. Anti-Herpes virus drugs contd..
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Agent Treatment of First
Episode
Treatment of Recurrent Episodes Suppression
Genital Herpes
Acyclovir, oral1 400 mg tid × 7–10 days
or 200 mg 5 times daily
800 mg tid × 2 days or 800 mg bid × 5
days
or 400 mg tid × 5 days
400–800 mg bid-tid
Famciclovir, oral 250 mg tid × 7–10 days 1000 mg bid × 1 day or 125 mg bid × 5
days
or 500 mg once then 250 mg bid × 2
days
250–500 mg bid
Valacyclovir, oral 1000 mg bid × 10 days 500 mg bid × 3 days or 1 g qd × 5 days 500–1000 mg qd–bid
Orolabial herpes
Acyclovir, oral 400 mg tid × 7–10 days
or 200 mg 5 times daily
200–400 mg 5 times daily × 5 days 400–800 mg bid–tid
Famciclovir, oral 500 mg tid × 7–10 days 1500 mg once or 750 mg bid 500 mg bid
Valacyclovir oral 1 g bid × 7–10 days 2 g bid × 1 day 500–1000 mg qd
Acyclovir topical (5% cream) 5 times daily . 4 days
Docosanol, topical (10% cream) 5 times daily
Penciclovir, topical (1% cream) Every 2 h while awake

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Severe HSV infection or
HSV infection in the
immunocompromised host
Acyclovir, IV 5–10 mg/kg q8h × 7–14 days
Herpes encephalitis Acyclovir, IV 10–15 mg/kg q8h × 21 days
Neonatal HSV infection Acyclovir, IV 10–20 mg/kg q8h × 14–21 days
Herpetic
keratoconjunctivitis
Ganciclovir(0.15% gel) 5 times daily
Trifluridine (1% solution) Every 2 hr
Varicella infection Acyclovir, oral 20 mg/kg (maximum 800 mg) qid × 5
days
Valacyclovir, oral 20 mg/kg (maximum, 1 g) tid × 5 days
Zoster infection Acyclovir, oral 800 mg 5 times daily × 7–10 days
Famciclovir, oral 500 mg tid × 7 days
Valacyclovir, oral 1 g tid × 7 days
Severe VZV infection or
VZV infection in the
immunocompromised host
Acyclovir, IV 10–15 mg/kg q8h × ≥7 days
Acyclovir-resistant HSV
or VZV infection
Foscarnet, IV 40–60 mg/kg q8h until healed

15. ◦ CMV infections occur in immunosuppression and are typically due to
reactivation of latent infection
◦ Dissemination of infection results in end-organ disease- retinitis, colitis,
esophagitis, central nervous system disease and pneumonitis
◦ Oral valganciclovir has decreased the use of IV ganciclovir, foscarnet &
cidofovir for the prophylaxis and treatment of end-organ CMV disease
◦ Oral valganciclovir has replaced oral ganciclovir
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Anti-cytomegalovirus drugs

16. ◦ Ganciclovir -
◦ analogue of guanosine
◦ virus specific thymidine kinase
◦ higher concentration inside CMV infected
cells is t½ > 24 hrs
◦ bioavailability - < 10%
◦ Mutation- same
◦ Used for prophylaxis and treatment of severe
CMV infections (pneumonia/colitis/retinitis)
in immunocompromised
◦ bone marrow depression, rash, fever,
vomiting, neuropsychic disturbances
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Anti-cytomegalovirus drugs
◦ Valganciclovir –
◦ valyl prodrug of ganciclovir
◦ Oral bioavailablility 60%
◦ Oral valganciclovir is equally effective as
i.v. ganciclovir
◦ Use –
◦ long term suppressive therapy of CMV
retinitis
◦ prophylaxis in transplant/
immunosuppressed patients
◦ Adverse effects- similar to ganciclovir

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Antiviral Drugs 17
Anti-cytomegalovirus drugs
◦ Cidofovir-
◦ analogue of cytidine
◦ does not require viral phosphokinase
◦ remains intracellularly for long periods so
weekly therapy
◦ i. v. infusion with pre and post dose oral
probenecid
◦ Uses-
 CMV retinitis in AIDS patients
 for acyclovir-resistant mucocutaneous herpes
simplex in immunosuppressed patients
 Topically for anogenital “wart”
◦ Foscarnet -
◦ inhibits viral DNA polymerase by blocking
pyrophosphate binding site
◦ Oral absorption – poor, t½ is 4- 8 hr
◦ acyclovir-resistant H. simplex, ganciclovir-
resistant CMV retinitis and other CMV
infections
◦ damages kidney, electrolyte imbalance,
anaemia, phlebitis, tremor, convulsions &
neurological

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Anti-cytomegalovirus drugs

19. Influenza virus are classified by their core proteins A,B,C species
Influenza A causes pandemics, is classified into 16 H (hemagglutinin) and 9
N (neuraminidase) subtypes based on surface proteins
Subtypes circulating among worldwide H1N1, H1N2, and H3N2
H5N1, H7N9 subtypes rapidly mutate
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Anti-influenza virus drugs
• Oseltamivir
• Zanamivir
• Peramivir
Neuraminidas
e inhibitors
• Amantadine
• Rimantadine
Adamantanes

20. Oseltamivir and Zanamivir – (analogs of sialic acid)
◦ Neuraminidase inhibitors active against both influenza A and B virus
◦ Competitively & reversibly interact with the active enzyme site to inhibit viral
neuraminidase activity resulting in clumping of newly released influenza virions
to each other & inhibit release of progeny
◦ Administered early as replication of virus peaks at 24–72 hours after the
onset of illness
◦ 75 mg twice daily for 5-day within 48 hours after the onset of illness
decreases the duration of symptoms, viral shedding & titer
◦ 75 mg once daily is for prophylaxis after exposure
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Anti-influenza virus drugs

21. ◦ Oseltamivir
◦ Oral
◦ Bioavailability ∼ 80%
◦ Nausea & gastric
irritation (reduced
by taking the drug
with food)
◦ DOC – H1N1, H5N1
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Anti-influenza virus drugs
◦ Zanamivir
◦ Inhalation
◦ concentration in the
respiratory 1000
times more
◦ Causes bronchospasm
◦ 10 mg twice daily for
5 days for treatment
or 10 mg once daily
for prevention
◦ Peramivir
◦ Activity against both
◦ 600-mg IV dose for
acute uncomplicated
influenza in adults
◦ diarrhea,
hypersensitivity
reactions

22. Amantadine & Rimantadine-
◦ Tricyclic amines of the adamantane family
◦ Block the M2 proton (ion channel) of the virus particle and inhibit uncoating of
the viral RNA & thus prevent its replication
◦ Active against influenza A only, Rimantadine is 4-10 times more active than
amantadine
◦ Due to high rates of resistance, no longer recommended for the prevention or
treatment of influenza
◦ Nausea, anorexia, nervousness, difficulty in concentrating, insomnia, light-
headedness, marked behaviral changes, delirium, hallucinations, agitation, and
seizures
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Anti-influenza virus drugs

23. Laninamivir – long acting neuraminidase inhibitor used for oseltamivir
resistant virus
Baloxavir – FDA approved on 24th oct 2018 for influenza given as oral
20mg & 40 mg
IV Zanamivir – phase III trial but showed its not superior to oral
oseltamivir
DAS181 – recombinant fusion protein, FDA approved for parainfluenza
virus infection in transplant recepeint patients, cleaves sialic acid
receptors on virus
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Antiviral Drugs 24
Newer Anti-influenza virus drugs

24. ◦ Hepatitis B virus (HBV) is a DNA virus integrate into host chromosomal DNA
to establish permanent infection
◦ Since virus cannot be eradicated, treatment is aimed as suppression of virus
and its inflammatory & hepatocyte damaging response
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Antiviral Drugs 25
Drugs for hepatitis-B
5 oral
Nucleoside/Nucleotide
analogs
Lamivudine, Adefovir
dipivoxil, Tenofovir
disoproxil, Entecavir,
Telbivudine
2 injectable
Interferon drugs
Interferon alfa-2b,
pegylated IFNalfa-2a

25. ◦ Interferon –
◦ Enhanced production of cytokines in body
◦ Bind to receptors & affect multiple steps- viral penetration, uncoating, m-RNA
synthesis, assembly of virion & release
◦ 3 types – IFN-a, IFN-β, IFN-γ only IFNa2a & IFNa2b produced by
recombinant technology used clinically
◦ Can be given by SC, IM, IV or intralesional route, doesn’t cross BBB
◦ IFN-a2b – for chronic HBV, HCV
◦ Polyethylene glycol with IFNs (pegylated IFN-a2b) once a week SC
◦ Flu-like symptoms, Neurotoxicity, Myelosuppression, Thyroid dysfunction,
Hypotension, reversible liver dysfunction
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Antiviral Drugs 26
Drugs for hepatitis-B

26. ◦ Advantages-
◦ Absence resistant variants
◦ Higher rate of viral load reduction
◦ Disadvantages-
◦ Adverse effects are more frequent & severe
◦ Not used in patients with decompensated disease
◦ Nucleoside/nucleotide analogue have better tolerability and higher
response than the interferons & are now the first line of therapy
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Antiviral Drugs 27
Drugs for hepatitis-B

27. 16-Jul-21
Antiviral Drugs 28
Drugs for hepatitis-B
◦ Entecavir –
◦ is an oral guanosine nucleoside analog
◦ inhibits HBV DNA polymerase
◦ bioavailability 100% but is decreased by food
◦ plasma half-life is 128–149 hours so once-daily dosing
◦ Effective than lamivudine or adefovir (resistant cases)

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Antiviral Drugs 29
Drugs for hepatitis-B
◦ Lamivudine-
◦ inhibits HBV DNA polymerase and HIV reverse transcriptase resulting in chain
termination
◦ rapid and potent virus suppression, but limited use because of emergence of
lamivudine resistant HBV isolates
◦ Adefovir and Tenofovir used against lamivudine resistant HBV
◦ Safest
◦ Adefovir dipivoxil-
◦ prodrug of adefovir, approved at lower doses for HBV infection
◦ phosphorylated by cellular kinases to the active diphosphate metabolite which inhibits
HBV DNA polymerase & chain termination
◦ Least active nucleotide analogue against HBV so not a first line drug
◦ Chronic hepatitis B, including lamivudine-resistant cases and concurrent HIV infection

29. ◦ Tenofovir disoproxil –
◦ activity against lamivudine & entecavir-resistant hepatitis virus isolates
◦ Higher rate of virologic response, histologic improvement & lower rate of
emergence of resistance
◦ Tenofovir alafenamide fumarate (TAF) is an oral prodrug of tenofovir with
minimized toxicities
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Antiviral Drugs 30
Drugs for hepatitis-B
◦ Telbivudine-
◦ Thymidine nucleoside analog
◦ Competitively inhibits HBV DNA polymerase & chain termination
◦ Induced greater virologic response than lamivudine & adefovir
◦ Not effective in patients with lamivudine-resistant HBV

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Antiviral Drugs 31
Drugs for hepatitis-B

31. Drugs for hepatitis-C
◦ Hepatitis C virus (HCV) is a RNA virus, which does not integrate into
chromosomal DNA instead causes frequent chronic hepatitis
◦ The aim of treatment is to attain sustained viral response (SVR) -
undetectable HCV-RNA in blood for at least 6 months after completion of
therapy
◦ Oral ribavirin with injected PegINFa is the standard therapy for HCV
infection
◦ However, first generation direct acting oral antiviral (DAA) drugs
(boceprevir & telaprevir) altered the treatment of hepatitis C
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Antiviral Drugs 33

32. Drugs for hepatitis-C
◦ Interferon – associated with serious adverse effects, longer duration of
treatment, frequent dosing
◦ First generation DAA plus pegIFN plus ribavirin improved effectiveness, but are
replaced by newer DAAs
◦ Main target of all newer DAAs HCV-encoded proteins & so inhibit replication
◦ All given oral, IFN free combinations with or without ribavirin & excreted-feces
◦ Improved efficacy, tolerability, improved dosing schedule & fewer drug-drug
interactions but are expensive combinations
◦ All combinations have excellent safety & low rate of discontinuation due to mild
adverse events 16-Jul-21
Antiviral Drugs 34
Non structural protein (NS)5A
inhibitors
NS5B nucleoside polymerase
inhibitors
NS5B non-nucleoside polymerase
inhibitors
NS 3/4A protease inhibitors

33. ◦ Ribavirin-
◦ Guanosine analogue has broad-spectrum antiviral activity
◦ Active against HCV, influenza A and B, Parainfluenza, respiratory
syncytial virus, HIV
◦ Mono & triphosphate derivatives generated intracellularly by host
kinases interfere GTP synthesis and viral RNA synthesis
◦ Oral bioavailability is - 50% increases with fatty meal
◦ Active against all genotypes of HCV & SVR in 50- 80% cases
◦ Dose-dependent hemolytic anemia, bone marrow depression
◦ Teratogenic
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Antiviral Drugs 35
Drugs for hepatitis-C

34. ◦ Daclatasvir
◦ Orally active NS5A inhibitor blocks HCV-RNA replication & assembly of
progeny virions
◦ Used with sofosbuvir for treatment of HCV genotypes 1, 2, 3
◦ t½ of daclatasvir is 12- 15 hr, no effect of food
◦ Metabolized by CYP3A
◦ SVR upto 90% after 12 week therapy in noncirrhotic but lower response
in cirrhotic
◦ No dose adjustment is required in mild-mod renal/hepatic impairment
◦ Headache, fatigue, abdominal pain, bradycardia, alopecia, anaemia and
rarely allergy
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Antiviral Drugs 36
Drugs for hepatitis-C
NS5A inhibitors:

35. ◦ Ledipasvir
◦ Available in a fixed-dose combination with sofosbuvir for HCV-1,4,5,6
◦ can be used in HIV coinfected
◦ LDV/SOF combination-SVR of 95- 99% cases after 12 weeks in
noncirrhotic & 24 weeks after in cirrhotic
◦ Absorption is dependent on gastric acid & impaired by taking H2
blockers/PPI
◦ t½ 47 hr
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Antiviral Drugs 37
Drugs for hepatitis-C
NS5A inhibitors:

36. ◦ Velpatasvir
◦ Available in a fixed-dose combination with the sofosbuvir
◦ Indicated in all ( 1- 6) genotypes of HCV
◦ Noncirrhotic - SVR of 95- 99% after 12 weeks
◦ Absorption is dependent on gastric acid
◦ t½ 15 hr
◦ Adverse effects - headache, fatigue, weakness and nausea
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Antiviral Drugs 38
Drugs for hepatitis-C
NS5A inhibitors:

37. ◦ Elbasvir
◦ Activity against variants resistant to earlier NS5A inhibitors & HCV 1,6
genotypes
◦ Used with grazoprevir regimen SVR reduced at 12 weeks
◦ Fatigue, headache, nausea & Elevated serum aminotransferases
◦ Ombitasvir
◦ Fixed-dose combination with paritaprevir + ritonavir for-HCV4, & with
dasabuvir + paritaprevir + ritonavir for HCV1
◦ C/I in patients with moderate or severe hepatic impairment
◦ Nausea, pruritus, insomnia & increased serum aminotransferases
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Antiviral Drugs 39
Drugs for hepatitis-C
NS5A inhibitors:

38. ◦ NS5B is an RNA-dependent RNA polymerase necessary for replication of HCV
◦ Enzyme has a catalytic site for nucleoside binding and 4 other sites at which non-
nucleoside compound can bind and cause allosteric alteration
◦ Nucleoside/nucleotide analogs (Sofosbuvir) target the catalytic site & activated
within the hepatocyte through phosphorylation to nucleoside triphosphate, which
competes with nucleotides, resulting in chain termination
◦ Non-nucleoside analogues (Dasabuvir) act at allosteric site
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Antiviral Drugs 40
Drugs for hepatitis-C
NS5B RNA Polymerase inhibitors:

39. ◦ Sofosbuvir
◦ Prodrug which is converted into active form in hepatocytes & then to its
triphosphate nucleotide which inhibits NS58 causes chain termination
◦ Active against all (1-6) HCV in combination with one of the NS5A inhibitors or
simeprevir or ribavirin ± PeglNFa
◦ SVR o f 85%- 99% after 12 weeks in noncirrhotic & upto 93% after 24 weeks
in cirrhotic
◦ Dasabuvir
◦ Non-nucleoside NS5B polymerase inhibitor
◦ Ombitasvir, Paritaprevir, and Ritonavir for HCV-1
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Antiviral Drugs 41
Drugs for hepatitis-C
NS5B RNA Polymerase inhibitors:

40. ◦ Paritaprevir
◦ Ombitasvir and ritonavir HCV-4 & with dasabuvir HCV-1
◦ Grazoprevir
◦ Potent, reversibly binds to HCV NS3/4A protease
◦ Shows activity against resistant variants
◦ Elbasvir for HCV 1 and 4
◦ Not to be administered moderate or severe hepatic impairment
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Antiviral Drugs 42
Drugs for hepatitis-C
NS3/4A Protease inhibitors: (serine protein required for post-
translational processing & transcription)

41. ◦ Simeprevir
◦ Active against HCV-1,4 is used along with sofosbuvir or ribavirin +
PegINFa
◦ Simeprevir - sofosbuvir-SVR in 83- 97% noncirrhotic after 12 weeks
cirrhotic patients after 24 weeks therapy
◦ adverse effects - nausea, headache, dyspnea, fatigue, rashes and
photosensitivity as it contains sulfa moiety
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Antiviral Drugs 43
Drugs for hepatitis-C
NS3/4A Protease inhibitors:

42. 16-Jul-21
Antiviral Drugs 44
Drugs for hepatitis-C

43. Other Antiviral drugs
Palivizumab
◦ Humanized monoclonal antibody – against an epitope in A antigen on F surface
protein of Respiratory syncytial virus
◦ Prevention of RSV infection in high-risk infants and children with
bronchopulmonary dysplasia or congenital heart disease
Aerosolized ribavirin (20 mg/mL for 12–18 hours continuously per day) to
children and infants with severe RSV bronchiolitis or pneumonia
◦ Lumicitabine – RNA polymerase inhibitor, phase II
◦ Ziresovir – viral fusion inhibitor completed phase II
◦ GS-5806 –phase II
◦ ALS-008176 – phase I
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Antiviral Drugs 45
RSV

44. Other Antiviral drugs
Imiquimod -An immune response modifier - effective in the topical
treatment of external & perianal warts (condyloma acuminatum) 5%
cream 3 times weekly
Intralesional injection of IFNa-2b or IFNa-n3 used condylomata
acuminata
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Antiviral Drugs 46

45. Corona virus drugs
Starting in December 2019 in Wuhan (Hubei province, China), a
novel coronavirus (CoV), causing severe acute respiratory syndrome
(SARS)-CoV-2, caused an international outbreak of a respiratory
illness (COVID-19) & is rapidly evolved into a pandemic
Remdesivir –
◦ first drug approved by the FDA May 1, 2020 for treating the SARS-
CoV-2 virus
◦ Adenosine triphosphate analogue competes with RNA chains leads to
delayed chain termination during replication
◦ IV 200 mg OD for 1day & IV 100 mg OD for 5days
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Antiviral Drugs 47

46. Corona virus drugs
Favipiravir –
◦ Pyrazincarboxamide derivative that acts new RNA-dependent RNA
polymerase inhibitor causing chain termination
◦ Oral 1800 mg BD f/b 800 mg BD for 7-14 days
Lopinavir – (800 mg daily in combination with 200 mg)
◦ An antiretroviral protease inhibitor used in combination with ritonavir
in HIV infection
◦ Peptidomimetic HIV type 1 aspartate spartate protease inhibitor that
acts by binding to its catalytic site, thereby, preventing th venting the
cleavage of viral polyprotein precursor
◦ Main difference with respect to the SARS-CoV-2 - cysteine protease
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Antiviral Drugs 48

47. Conclusion :
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Antiviral Drugs 49
◦ The knowledge of mechanism of viral replication provided insight into the
critical steps in viral life cycle
◦ This serves the potential target for antiviral drugs
◦ Antiviral drugs are classified according to virus & to the mechanism
inhibiting viral life cycle
◦ Whereas, some infections require monotherapy & some require multiple drug
therapy
◦ Recent research has focused on identifying agents with greater selectivity,
higher potency & reduced toxicity

48. References:
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Antiviral Drugs 50
Harry W. Lampiris, MD, & Daniel S. Maddix, Pharm D, Chapter 48
Antifungal Agents, Bertram G. Katzung Basic & Clinical Pharmacology
14th Edition; 869.
The pharmacological basis of Therapeutics 13th edition,
Chapter62,Antiviral Agents (Nonretroviral) Edward P. Acosta, 1105.
Principles of pharmacology HL sharma KK sharma 3rd edition, Antiviral
drugs for non-retroviral infections, 789.
https://pubmed.ncbi.nlm.nih.gov

49. Thank You..