Module 9 14 Antivirals Flashcards
(258 cards)
1
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Question
A
Answer
2
Q
What is the primary focus of this chapter regarding antiviral drugs?
A
This chapter discusses antiviral drugs used to treat infections caused by viruses other than human immunodeficiency virus (HIV).
3
Q
Where can you find information on the specific antiviral drugs for non-HIV infections?
A
Information on antiviral drugs for non-HIV infections is available in Table 80.1.
4
Q
What does this section provide information about?
A
This section lists various antiviral drugs and their spectrum of activity against specific viruses.
5
Q
Why are antiviral drugs more specific compared to antibiotics?
A
Antiviral drugs are more specific because they are designed to target particular viruses, whereas antibiotics are used to treat various bacterial infections.
6
Q
How are the antiviral drugs categorized in this list?
A
Antiviral drugs are categorized based on the associated viral infections they are designed to treat.
7
Q
What are HSV and VZV, and what group of viruses do they belong to?
A
HSV stands for Herpes Simplex Virus, and VZV stands for Varicella Zoster Virus. They belong to the herpesvirus group.
8
Q
What infections are caused by HSV in the body?
A
HSV causes infections in various body sites, including the genitalia, mouth, face, and others.
9
Q
What diseases are associated with VZV, and what is herpes zoster?
A
VZV is responsible for causing varicella (chickenpox) and herpes zoster (shingles). Herpes zoster is a painful condition resulting from the reactivation of dormant VZV in sensory nerve roots.
10
Q
Who is primarily affected by varicella, and what kind of disease is it?
A
Varicella (chickenpox) primarily affects children and is a contagious viral disease.
11
Q
In which chapters can you find more detailed information on these conditions?
A
More detailed information on these conditions can be found in Chapter 55 for varicella and Chapter 82 for genital herpes.
12
Q
What is Acyclovir, and what types of viral infections is it commonly used to treat?
A
Acyclovir (Zovirax) is a medication used to treat infections caused by Herpes Simplex Virus (HSV) and Varicella Zoster Virus (VZV).
13
Q
How can Acyclovir be administered for treatment?
A
Acyclovir can be administered topically, orally, and intravenously depending on the type and location of the viral infection.
14
Q
Are serious side effects associated with Acyclovir?
A
Serious side effects from Acyclovir are uncommon.
15
Q
Which viral family is Acyclovir effective against, and name some specific viruses within this family?
A
Acyclovir is effective against viruses in the herpesvirus family, including herpes simplex viruses (HSV), varicella zoster virus (VZV), and cytomegalovirus (CMV).
16
Q
Among the viruses treated with Acyclovir, which one is the most sensitive to the drug?
A
Herpes simplex viruses (HSV) are the most sensitive to Acyclovir.
17
Q
How does the sensitivity to Acyclovir vary among the different viruses in the herpesvirus family?
A
Varicella zoster virus (VZV) is moderately sensitive, while most strains of cytomegalovirus (CMV) are resistant to Acyclovir.
18
Q
How does Acyclovir inhibit viral replication?
A
Acyclovir inhibits viral replication by suppressing the synthesis of viral DNA.
19
Q
What is the initial step required for Acyclovir to become active against herpesviruses?
A
Acyclovir must be converted to acyclo-guanosine monophosphate (GMP) by the viral enzyme thymidine kinase.
20
Q
How does acyclo-GMP exert its antiviral effects?
A
Acyclo-GMP is further converted to acyclo-guanosine triphosphate (GTP), which directly inhibits viral DNA synthesis.
21
Q
Why are herpes simplex viruses (HSVs) highly sensitive to Acyclovir?
A
HSVs are sensitive to Acyclovir because the drug is a better substrate for thymidine kinase produced by HSVs compared to mammalian thymidine kinase, leading to preferential activation in HSV-infected cells.
22
Q
Why is cytomegalovirus (CMV) inherently resistant to Acyclovir?
A
CMV is resistant to Acyclovir because the drug is a poor substrate for the thymidine kinase produced by CMV, resulting in limited drug activation.
23
Q
How can herpesviruses develop resistance to acyclovir?
A
Herpesviruses can develop resistance to Acyclovir through three mechanisms: (1) decreased production of thymidine kinase, (2) alteration of thymidine kinase to prevent the conversion of Acyclovir to its active form, acyclo-GMP, and (3) modification of viral DNA polymerase to reduce sensitivity to inhibition.
24
Q
What is the most common mechanism of resistance to acyclovir?
A
Thymidine kinase deficiency is the most common mechanism of resistance to Acyclovir.
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Is resistance to acyclovir common in individuals with a healthy immune system?
Resistance to acyclovir is rare in individuals with a healthy immune system.
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In which patient populations is resistance to acyclovir more commonly observed?
Resistance to acyclovir is more commonly observed in transplant recipients and patients with AIDS.
27
What alternative treatments are used for lesions caused by acyclovir-resistant herpesviruses?
Intravenous drugs like foscarnet or cidofovir are used to treat lesions caused by acyclovir-resistant herpesviruses.
28
Which herpes simplex virus (HSV) type is usually responsible for herpes infections of the face and oropharynx?
Herpes infections of the face and oropharynx are typically caused by HSV type 2 (HSV-2).
29
What is the treatment option for primary herpes infections of the gums and mouth in immunocompetent patients?
In immunocompetent patients, oral acyclovir can be used to treat primary infections of the gums and mouth.
30
How can oral acyclovir be used to prevent recurrent herpes labialis (cold sores)?
Oral acyclovir can be taken prophylactically to prevent episodes of recurrent herpes labialis (cold sores).
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Is there a highly effective treatment for active herpes labialis?
No, there is no truly effective treatment for active herpes labialis.
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What is the recommended treatment for severe mucocutaneous herpes infections in immunocompromised patients?
For severe mucocutaneous herpes infections in immunocompromised patients, intravenous acyclovir is the treatment of choice.
33
What is the recommended treatment for herpes zoster (shingles) in older adults?
High doses of oral acyclovir are effective for herpes zoster (shingles) in older adults.
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Is oral acyclovir effective for varicella (chickenpox), and for which age groups?
Oral acyclovir is effective for varicella (chickenpox) in children, adolescents, and adults, as long as dosing is initiated early (within 24 hours of rash onset).
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What is the preferred treatment for VZV infection in immunocompromised individuals?
Intravenous acyclovir is the treatment of choice for VZV infection in immunocompromised individuals.
36
Where can you find detailed information about the characteristics and treatment of genital HSV (herpes simplex virus) infection?
Detailed information about genital HSV infection can be found in Chapter 82.
37
In what forms can acyclovir be administered?
Acyclovir can be administered topically, orally, and intravenously.
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What is the oral bioavailability of acyclovir?
The oral bioavailability of acyclovir is low, ranging from 15% to 30%.
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Is there significant absorption of acyclovir through the skin when topically applied?
No, there is no significant absorption of acyclovir when applied topically.
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What is the half-life of acyclovir in individuals with normal kidney function?
In individuals with normal kidney function, acyclovir has a half-life of 2.5 hours.
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How does renal impairment affect the half-life of acyclovir?
Renal impairment can prolong the half-life of acyclovir, reaching 20 hours in patients with anuria.
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What should be done with acyclovir dosages in patients with kidney disease?
Dosages of acyclovir should be reduced in patients with kidney disease.
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What is the peak time for Valacyclovir (Valtrex) after administration?
The peak time for Valacyclovir is 1.5 hours.
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What is the protein binding percentage for Acyclovir (Sitavig, Zovirax)?
The protein binding for Acyclovir is 9%-33%.
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How is Acyclovir (Sitavig, Zovirax) metabolized?
Acyclovir is metabolized by cellular enzymes.
46
What is the half-life of Famciclovir (Famvir)?
The half-life of Famciclovir is 2-4 hours.
47
In which organs is Famciclovir eliminated?
Famciclovir is eliminated in the urine (73%) and feces (25%).
48
Is there any metabolism involved in the processing of Foscarnet (Foscavir)?
No, there is no metabolism involved in the processing of Foscarnet.
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How is Valacyclovir (Valtrex) metabolized?
Valacyclovir is converted in the liver to acyclovir, which is then processed by cellular enzymes.
50
What are some common side effects associated with Acyclovir?
Common side effects of Acyclovir include nausea, vomiting, diarrhea, headache, and vertigo.
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Is renal impairment associated with the use of Acyclovir?
No, renal impairment has not been reported with the use of Acyclovir.
52
What is one of the potential side effects of topical Acyclovir?
Topical Acyclovir may cause transient local burning or stinging.
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Is Acyclovir considered safe for use during pregnancy?
Yes, **oral Acyclovir is safe during pregnancy** and can be used to suppress recurrent genital herpes near term in pregnant individuals.
54
What is the potential risk associated with intravenous (IV) Acyclovir?
IV Acyclovir can potentially cause renal failure.
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Who is at increased risk of renal failure due to IV Acyclovir?
Patients with preexisting renal disease and dehydration are at an increased risk of experiencing this adverse effect.
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What should patients be informed about regarding the use of Acyclovir?
Patients should be informed that Acyclovir only decreases symptoms of viral infections; it does not eliminate the virus and does not produce a cure.
57
What precaution should patients take when applying topical Acyclovir?
Patients should apply topical Acyclovir with a finger cot or rubber glove to prevent viral transfer to other body sites or other people.
58
What should patients be told about any transient local burning or stinging they may experience when using topical Acyclovir?
Patients should be told that transient local burning or stinging may occur when applying topical Acyclovir, but this is considered a normal reaction and not a cause for concern.
59
What is the recommended dosage of Acyclovir for orolabial HSV (herpes simplex virus)?
For orolabial HSV, the dosage of Acyclovir is to apply cream five times daily for 4 days when used topically.
60
How should Acyclovir be dosed for Varicella in children over 40 kg?
The dosage information for Acyclovir for Varicella in children over 40 kg is not provided.
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At what age is Acyclovir approved for use in children?
Acyclovir is approved for children as young as 3 months of age.
62
What is the recommended age for using Valacyclovir in children?
Valacyclovir is approved for children 2 years of age.
63
Why is Foscarnet not recommended during pregnancy?
Foscarnet is not recommended during pregnancy because it has caused abnormal development of tooth enamel in animal studies.
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For pregnant women, did epidemiologic reviews find a significant increase in abnormal outcomes with acyclovir, famciclovir, and valacyclovir use?
No, epidemiologic reviews did not find a significant increase in abnormal outcomes for pregnant women using acyclovir, famciclovir, and valacyclovir.
65
What are the breastfeeding recommendations for women taking systemic drugs for HSV and VZV?
Women taking systemic drugs for HSV and VZV are recommended to avoid breastfeeding due to the potential for serious adverse events in infants.
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Why should older adults with renal impairment be cautious when taking acyclovir and valacyclovir?
Older adults with renal impairment should be cautious when taking acyclovir and valacyclovir because they are at greater risk for adverse CNS effects.
67
What is Acyclovir used for?
Acyclovir is used for HSV (Herpes Simplex Virus) infections.
68
Which drug is used for Cytomegalovirus (CMV) infections?
Ganciclovir is used for CMV (Cytomegalovirus) infections.
69
Name a nucleoside analog used for hepatitis.
Lamivudine is a nucleoside analog used for hepatitis.
70
What is the purpose of Simeprevir in hepatitis treatment?
Simeprevir is a protease inhibitor used for hepatitis.
71
Which drug is an NS5A inhibitor used for hepatitis?
Daclatasvir is an NS5A inhibitor used for hepatitis.
72
What is the function of Sofosbuvir in hepatitis treatment?
Sofosbuvir is an NS5B inhibitor used for hepatitis.
73
What type of drug is Peginterferon alfa-2a, and what is its use?
Peginterferon alfa-2a is an interferon used for hepatitis.
74
What is the purpose of the influenza vaccine?
The influenza vaccine is used to prevent influenza.
75
What is the role of Oseltamivir in influenza treatment?
Oseltamivir is a neuraminidase inhibitor used for influenza.
76
Which drug acts as an endonuclease inhibitor for influenza?
Baloxavir marboxil is an endonuclease inhibitor used for influenza.
77
What is the function of Palivizumab, and for which viral infection is it used as prophylaxis?
Palivizumab is a monoclonal antibody used for prophylaxis of Respiratory Syncytial Virus (RSV) infection.
78
What is Valacyclovir?
Valacyclovir is a prodrug form of acyclovir.
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How does the effective bioavailability of acyclovir change when taking Valacyclovir orally?
Valacyclovir increases the effective bioavailability of acyclovir to about 55%.
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What conditions is Valacyclovir approved for managing?
Valacyclovir is approved for managing:Herpes labialis (cold sores). Varicella (chickenpox). Herpes zoster infection (shingles). Herpes simplex genitalis (genital herpes).
81
In what situations is Valacyclovir sometimes used off-label?
Valacyclovir is sometimes used off-label for the prophylaxis of HSV (Herpes Simplex Virus), VZV (Varicella Zoster Virus), and CMV (Cytomegalovirus) infections in patients with cancer.
82
What is another use of Valacyclovir in cancer patients?
Valacyclovir is sometimes used to treat cancer-related HSV and VZV infections.
83
What syndrome has been observed in immunocompromised patients during clinical research on valacyclovir?
Clinical research has revealed the occurrence of a syndrome known as thrombotic thrombocytopenic purpura/hemolytic uremic syndrome (TTP/HUS).
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Is TTP/HUS generally observed in immunocompetent patients?
No, TTP/HUS has not been observed in immunocompetent patients.
85
Why has the US Food and Drug Administration (FDA) not approved the use of valacyclovir in most immunocompromised patients?
The FDA has not approved valacyclovir for most immunocompromised patients due to the risk of TTP/HUS, except for chronic suppressive therapy for recurrent genital herpes in HIV-infected patients.
86
Despite FDA recommendations, are there increasing recommendations in the literature for valacyclovir use in immunocompromised patients?
Yes, there are increasing recommendations in the literature for valacyclovir use in immunocompromised patients, but caution is advised.
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In clinical trials, what dose of valacyclovir was associated with the occurrence of TTP/HUS in immunocompromised patients?
TTP/HUS occurred in clinical trials when immunocompromised patients were receiving high doses of 8 g/day of valacyclovir.
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What are some common side effects associated with valacyclovir, aside from TTP/HUS?
Common side effects of valacyclovir include nausea, vomiting, diarrhea, headache, and vertigo.
89
What is famciclovir, and how does it work?
Famciclovir is a prodrug of penciclovir, which inhibits viral DNA replication. It undergoes enzymatic conversion to penciclovir, and then to penciclovir triphosphate, its active form.
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What is the role of penciclovir triphosphate in viral infections?
Penciclovir triphosphate inhibits viral DNA polymerase, preventing the replication of viral DNA.
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How is the formation of penciclovir triphosphate facilitated within infected cells?
Formation of penciclovir triphosphate requires the action of viral thymidine kinase, limiting its effects to infected cells while sparing most host cells.
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Against which viruses is penciclovir active in vitro?
Penciclovir exhibits in vitro activity against HSV type 1 (HSV-1), HSV-2, and VZV.
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For what medical conditions is famciclovir approved for treatment?
Famciclovir is approved for the treatment of acute herpes zoster (shingles) and herpes simplex genitalis (genital herpes).
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Does famciclovir reduce the incidence of postherpetic neuralgia in patients with herpes zoster?
No, famciclovir does not reduce the incidence of postherpetic neuralgia, but it can decrease its duration.
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Is famciclovir well-tolerated by patients?
Yes, famciclovir is generally well tolerated.
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What are the common side effects associated with famciclovir use?
Common side effects include headache and nausea and were reported by more than 10% of subjects in clinical trials.
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Under what circumstances can acute renal failure occur due to famciclovir use?
Acute renal failure can occur when higher than recommended doses of famciclovir are administered.
98
How many topical drugs are used for the treatment of recurrent herpes labialis?
There are three topical drugs available.
99
Name two of the topical drugs used for treating herpes labialis.
Two of the drugs used for treating herpes labialis are penciclovir and docosanol.
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What is the third drug used for treating herpes labialis?
The third drug used for treating herpes labialis is acyclovir.
101
What is penciclovir (Denavir) used to treat?
Penciclovir (Denavir) is used to treat recurrent herpes labialis, commonly known as cold sores.
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Which types of herpes simplex viruses (HSV) is penciclovir effective against?
Penciclovir is effective against HSV-1 and HSV-2.
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How does penciclovir work to suppress viral replication?
Penciclovir works by inhibiting the DNA polymerase enzyme responsible for viral DNA synthesis.
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In what form is penciclovir available, and how should it be applied?
Penciclovir is available as a 1% cream, and it should be applied every 2 hours (except during sleep) for a 4-day period.
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What benefits were observed in clinical trials for penciclovir in the treatment of herpes labialis?
Clinical trials showed modest benefits, reducing the average healing time and pain duration by approximately half a day (from 5 days down to 4.5 days).
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What is the most common side effect associated with penciclovir use?
The most common side effect is mild local erythema (redness).
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What is docosanol (Abreva) used for?
Docosanol is used to treat recurrent herpes labialis, which are cold sores that appear on or around the lips.
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In what form is docosanol available, and how often should it be applied?
Docosanol is available as a 10% cream, and it should be applied five times a day.
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How does docosanol compare to other treatments in terms of reducing the time to healing for herpes labialis?
In one trial, docosanol reduced the time to healing from 4.8 days to 4.1 days, which is similar to the response seen with penciclovir.
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What is the mechanism of action of docosanol in treating herpes labialis?
Docosanol blocks viral entry into host cells instead of inhibiting viral DNA synthesis, which is a unique mechanism of action.
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How does docosanol affect the ability of viruses to bind to host cells?
Docosanol does not prevent viruses from binding to cells, and viable virions can remain attached to the cell surface for an extended period.
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Why is docosanol considered unlikely to promote resistance in viruses?
Because docosanol does not affect processes of viral replication, it is considered unlikely to promote resistance.
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What is trifluridine (Viroptic) primarily used to treat?
Trifluridine is indicated for the topical treatment of ocular infections caused by HSV-1 and HSV-2 (herpes simplex viruses).
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What types of ocular infections is trifluridine used to treat?
Trifluridine is used to treat acute keratoconjunctivitis and recurrent epithelial keratitis, which are ocular infections.
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How does trifluridine exert its antiviral effects?
Trifluridine's antiviral effects result from inhibiting DNA synthesis in the affected cells.
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What are the common side effects associated with the use of trifluridine?
Common side effects include localized burning and stinging, and eyelid edema occurs in about 3% of patients.
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Does systemic absorption of trifluridine occur after topical administration?
Systemic absorption of trifluridine after topical administration is minimal.
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Is trifluridine associated with systemic toxicity when used as prescribed?
No, trifluridine is devoid of systemic toxicity when used as prescribed for the topical treatment of ocular infections.
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What is the primary indication for Ganciclovir 0.15% ophthalmic gel (Zirgan)?
The primary indication for Ganciclovir 0.15% ophthalmic gel, known as Zirgan, is the treatment of acute herpetic keratitis.
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What is acute herpetic keratitis?
Acute herpetic keratitis is a condition characterized by inflammation and ulceration of the cornea that occurs due to infection with a herpes simplex virus.
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How does Ganciclovir ophthalmic gel provide its benefits for treating herpetic keratitis?
The benefits of Ganciclovir ophthalmic gel result from its ability to suppress viral replication within the eye.
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What are some of the common adverse effects associated with the use of Ganciclovir ophthalmic gel?
Common adverse effects include blurred vision, eye irritation, and red eyes.
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Does the use of Ganciclovir ophthalmic gel lead to any systemic effects in the body?
No, the use of Ganciclovir ophthalmic gel does not result in any systemic effects; it primarily acts locally in the eye.
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What is the therapeutic goal when using these medications for the treatment of HSV and VZV outbreaks?
The therapeutic goal when using these medications for the treatment of HSV and VZV outbreaks is to alleviate signs and symptoms associated with HSV and VZV outbreaks.
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What baseline data should be collected before starting treatment with these medications?
Before treatment, collect baseline data, which includes serum creatinine, blood urea nitrogen (BUN), urinalysis, and a CBC with WBC differential.
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Are there any additional drug-specific baseline data required for these medications?
Yes, some medications have specific baseline data requirements:Acyclovir and Valacyclovir require liver enzyme levels to be checked.Foscarnet requires baseline data for electrolytes, 24-hour creatinine clearance, and an electrocardiogram (ECG).
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What kind of monitoring is recommended during treatment with these medications?
During treatment, monitor the patient's serum creatinine (and BUN if needed), as well as their CBC.For Acyclovir, monitor urinalysis, urine output, and liver enzymes.For Valacyclovir, monitor urinalysis and liver enzymes.For Foscarnet, monitor electrolytes, calcium, ionized calcium, magnesium, and phosphorus.
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Who are considered high-risk patients in this context?
High-risk patients are those with impaired renal function.
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Are there any additional high-risk factors specific to certain medications?
For Foscarnet, high-risk factors include patients with QT prolongation, hypocalcemia, hyper/hypophosphatemia, hypomagnesemia, hypokalemia, and those with heart failure (due to the high sodium content of the drug).
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How do you evaluate whether the treatment is effective?
To evaluate the effectiveness of treatment, observe for improvement in the signs and symptoms of the acute infection and check whether the infection is under control.
131
What is influenza and why is it a concern?
Influenza is a serious respiratory tract infection that poses a major risk to health worldwide due to its morbidity and mortality.
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What kinds of complications can arise from influenza?
Influenza can lead to complications like bronchitis and pneumonia, which, in the U.S., result in up to 300,000 hospitalizations annually.
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How does annual influenza-related mortality vary, and can you provide an example?
Annual influenza-related deaths can fluctuate based on the circulating strain. For example, during the 2017-2018 epidemic, there were 185 child deaths, with 80% of them being unvaccinated.
134
Are adult deaths due to influenza notifiable, and what are some statistics related to influenza hospitalizations?
Adult influenza deaths are generally not notifiable. However, during the same epidemic, there were an estimated 710,000 hospitalizations for influenza. Around 58% of these patients were 65 years and older.
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What is the economic cost associated with influenza, and how is it divided?
The economic burden of influenza is substantial. Direct costs are estimated to be greater than $10 billion per year, and indirect costs related to lost income are greater than $16 billion annually.
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What are the two major types of influenza viruses, and which is more common?
Influenza is caused by influenza A and influenza B viruses. Influenza A viruses are more common, causing approximately 96% of infections.
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How are influenza A viruses further classified, and what are the current dominant subgroups?
Influenza A viruses are classified based on two surface antigens: hemagglutinin (H) and neuraminidase (N). The main subgroups in circulation today are H1N1 and H3N2.
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Why is it important to understand that influenza viral strains evolve?
It is important to understand that influenza viral strains evolve because the specific strains of H1N1 and H3N2 in circulation in one year may be different from those in the following year.
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How is influenza primarily transmitted from person to person?
Influenza is mainly spread through aerosolized droplets produced by coughing or sneezing.
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Where does the influenza virus enter the body, and where does viral replication occur?
The virus enters the body through the mucous membranes of the nose, mouth, or eyes, and viral replication takes place in the respiratory tract.
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How long does it take for influenza symptoms to appear after exposure, and what are some common symptoms?
Symptoms usually appear 2 to 4 days after exposure and can include fever, cough, chills, sore throat, headache, and muscle pain (myalgia).
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What is the typical duration of restricted activity, bed disability, and absence from work or school for a patient with influenza?
For a typical patient, influenza results in 5 to 6 days of restricted activity, 3 to 4 days of bed disability, and 3 days of absence from work or school.
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What is the primary management strategy for influenza, and what is the role of drug therapy?
The primary management strategy for influenza is vaccination, while drug therapy is considered a secondary approach.
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Why is annual vaccination essential to protect against influenza?
Annual vaccination is crucial because influenza viruses continually change, making annual updates of the vaccine necessary.
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What determines the composition of the annual influenza vaccine, and how many strains does it typically target?
The composition of the annual influenza vaccine is based on the three (trivalent) or four (quadrivalent) strains of the influenza virus expected to be most common in the upcoming flu season.
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Who collaboratively identifies and selects the strains included in the influenza vaccine each year?
The CDC, FDA, and the World Health Organization (WHO) work together to identify and select the strains for the annual influenza vaccine.
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What are the three main types of influenza vaccines available?
The three main types of influenza vaccines are inactivated influenza vaccine (IIV), recombinant hemagglutinin vaccine (RIV), and live, attenuated influenza vaccine (LAIV).
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How are IIV and RIV administered?
IIV and RIV are administered by intramuscular injection, except for the exception Fluzone Intradermal, which uses intradermal injection.
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How is the LAIV administered?
LAIV is administered through an intranasal spray.
150
Where can additional information on each influenza vaccine be found?
Additional information on each influenza vaccine can be found in Table 80.12.
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What are the four main types of influenza vaccines?
The four main types of influenza vaccines are Inactivated Influenza Vaccine, Quadrivalent (IIV4), Inactivated Influenza Vaccine, Trivalent (IIV3), Recombinant Influenza Vaccine, Quadrivalent (RIV4), and Live Attenuated Influenza Vaccine, Quadrivalent (LAIV4).
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Which vaccines are approved for children aged 6 months and older?
The vaccines approved for children aged 6 months and older are Afluria Quadrivalent, Fluarix Quadrivalent, FluLaval Quadrivalent, and Fluzone Quadrivalent.
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What type of vaccine uses cell culture–grown virus and is approved for ages 4 and older?
The vaccine that uses cell culture–grown virus and is approved for ages 4 and older is Flucelvax Quadrivalent.
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Which vaccine is approved for adults aged 18 and older and contains recombinant hemagglutinin?
The vaccine approved for adults aged 18 and older that contains recombinant hemagglutinin is Flublok Quadrivalent.
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What is the age range for which FluMist Quadrivalent is approved?
FluMist Quadrivalent is approved for individuals aged 2–49 years.
156
What is the general onset of protection after receiving the influenza vaccine?
Protection generally begins 1 to 2 weeks after vaccination.
157
For which group is the Fluzone High-Dose vaccine designed?
Fluzone High-Dose vaccine is specifically designed for individuals aged 65 and older.
158
Why is annual revaccination recommended for some people?
Annual revaccination is recommended because antibody titers can decline fairly quickly, and it helps maintain protection even if the vaccine formulation does not change.
159
How do adverse effects of the inactivated influenza vaccine (IIV) and the live attenuated influenza vaccine (LAIV) compare?
Adverse effects differ between IIV and LAIV.
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Are significant adverse effects common with influenza vaccines?
No, significant adverse effects are rare for all influenza vaccines.
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What are some of the common adverse effects of influenza vaccination?
Common adverse effects of influenza vaccination include soreness at the injection site, fever, myalgia, and malaise, especially in individuals not previously vaccinated.
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Is there a risk of Guillain-Barré Syndrome (GBS) associated with influenza vaccines?
Yes, there is a very small risk, estimated at about one or two cases per million vaccine recipients. However, this risk is much smaller than the risk of severe influenza.
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What is LAIV, and when was it first approved?
LAIV stands for Live Attenuated Influenza Vaccine, and it was approved in 2003.
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Have reports of serious adverse events related to LAIV been common or rare?
Reports of serious adverse events have been relatively rare among individuals who received LAIV.
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What are some of the most common side effects associated with LAIV?
The most common side effects of LAIV include nasal congestion with rhinorrhea, lethargy, headache, sore throat, and decreased appetite.
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What should individuals with an acute febrile illness do regarding influenza vaccination?
Individuals with an acute febrile illness should delay influenza vaccination until their symptoms subside.
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Can individuals with minor illnesses like the common cold receive the influenza vaccine?
Yes, individuals with minor illnesses like the common cold, even if they don't have a fever, can receive the influenza vaccine.
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Why was there concern about administering vaccines to individuals with egg allergies?
The concern was because vaccines are produced from viruses grown in eggs, potentially containing trace amounts of egg proteins.
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What do updated recommendations published in August 2018 state regarding individuals with a history of egg allergy?
Updated recommendations indicate that people with a history of egg allergy of any severity can safely receive any licensed, recommended, and age-appropriate influenza vaccine (IIV, RIV4, or LAIV4).
170
What prompted these updated recommendations for individuals with egg allergies?
These recommendations followed extensive reviews demonstrating that vaccinating individuals with reported egg allergies is less risky than once believed.
171
Who does the ACIP recommend should receive annual influenza vaccination?
The ACIP recommends annual influenza vaccination for everyone aged 6 months and older.
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Why is annual vaccination especially important for certain individuals?
Annual vaccination is especially crucial
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Who are considered to be in the high-risk groups for flu complications?
High-risk groups include children under 5 years old, especially those under 2 years, children aged 18 or younger receiving long-term aspirin therapy, pregnant women, people aged 65 and older, morbidly obese individuals, residents of nursing homes and long-term care facilities, Native Americans/Alaskan Natives, immunosuppressed individuals, and people with certain chronic medical conditions.
174
What type of influenza vaccine should individuals in these high-risk groups receive, and why?
Individuals in these high-risk groups should receive the inactivated influenza vaccine only, and they should not receive the live influenza vaccine because the safety of the live vaccine hasn't been adequately evaluated in these populations.
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What type of influenza vaccine should individuals at high risk for flu complications, including pregnant women, avoid, and what should they receive instead?
Individuals at high risk should avoid the live influenza vaccine and receive the inactivated vaccine.
176
What is the only contraindication in the current recommendations for influenza vaccination?
The only contraindication is a severe allergic reaction to influenza vaccine or one of its components.
177
Was Guillain-Barré syndrome (GBS) previously considered a contraindication for further influenza vaccinations, and what is its status in the most current guidelines?
GBS occurring within 6 weeks following vaccine administration was previously considered a contraindication, but the current guidelines have given it a precautionary status, meaning it's not a strict contraindication.
178
What is another precaution when it comes to influenza vaccination?
Another precaution is the presence of a moderate to severe acute illness at the time of planned vaccination.
179
When does the influenza "season" typically begin and end in the United States?
The influenza "season" typically begins in November and extends through March or April.
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When does the influenza season usually peak?
The influenza season usually peaks in January or February.
181
What is the best time to get vaccinated for full protection against influenza?
The best time to vaccinate is in October or November.
182
Is it still beneficial to get vaccinated if someone missed the ideal vaccination time, and if so, until when?
Vaccinating as late as April can still be beneficial.
183
Can influenza vaccines be given at the same time as other vaccines?
Influenza vaccines can be administered at the same time as other vaccines, including the pneumococcal vaccine.
184
How many classes of antiviral drugs are available for influenza prevention and treatment, and what are they?
There are three classes of antiviral drugs for influenza: adamantanes, neuraminidase inhibitors, and endonuclease inhibitor.
185
Name the first class of antiviral drugs used for influenza.
The first class of antiviral drugs is adamantanes.
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What is the second class of antiviral drugs used for influenza?
The second class of antiviral drugs is neuraminidase inhibitors.
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What is the third class of antiviral drugs used for influenza?
The third class of antiviral drugs is endonuclease inhibitor.
188
What are the adamantanes in the context of influenza treatment?
The adamantanes consist of drugs like amantadine (Symmetrel) and rimantadine (Flumadine).
189
Were adamantanes the first drugs available for influenza treatment?
Yes, adamantanes were the first influenza drugs available.
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Are most current strains of influenza A susceptible to adamantanes?
No, most current strains of influenza A are resistant to adamantanes.
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Are adamantanes effective against influenza B?
No, all strains of influenza B are resistant to adamantanes.
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What is the recommendation from the CDC regarding the use of adamantanes for influenza treatment?
The CDC recommends against using adamantanes for any influenza patients, whether infected with influenza A or influenza B.
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What types of influenza are the neuraminidase inhibitors effective against?
Neuraminidase inhibitors are effective against influenza A and influenza B.
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How many neuraminidase inhibitors are currently available?
There are three neuraminidase inhibitors available.
195
Which of the neuraminidase inhibitors is available only for intravenous delivery?
Peramivir (Rapivab) is available only for intravenous delivery.
196
Are oseltamivir and zanamivir suitable as a replacement for annual influenza vaccination?
No, oseltamivir and zanamivir are not a substitute for annual vaccination.
197
In what situations can oseltamivir provide protection for unvaccinated individuals?
Oseltamivir can provide some protection during a community outbreak or when there are community outbreaks despite widespread vaccination with different virus strains.
198
When should dosing with neuraminidase inhibitors for influenza treatment ideally begin?
Dosing should ideally begin no later than 2 days after symptom onset.
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What happens to the benefits of treatment with neuraminidase inhibitors as treatment is delayed?
The benefits of treatment decline significantly when treatment is delayed.
200
How much does symptom duration reduce when treatment is initiated within 12 hours of symptom onset?
Starting treatment within 12 hours of symptom onset can reduce symptom duration by more than 3 days.
201
When started within 24 hours, how much does treatment reduce symptom duration?
Starting treatment within 24 hours can reduce symptom duration by less than 2 days.
202
What is the reduction in symptom duration when treatment begins within 36 hours of symptom onset?
Starting treatment within 36 hours results in a reduction of symptom duration by only 29 hours.
203
What is the primary function of oseltamivir (Tamiflu) in the context of influenza?
Oseltamivir is used for preventing and treating influenza by reducing symptom duration, severity, and complications.
204
Who does the American College of Obstetricians and Gynecologists (ACOG) recommend oseltamivir for?
ACOG recommends oseltamivir for both prophylaxis and treatment in pregnant women to protect the developing embryo and fetus from influenza.
205
How does oseltamivir exert its antiviral effects in treating influenza?
Oseltamivir works by inhibiting neuraminidase, a viral enzyme necessary for replication, which stops the release of new viral particles and halts viral spread.
206
Against which strains of influenza is oseltamivir effective?
Oseltamivir is effective against most strains of both influenza A and B.
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Is the development of resistance to oseltamivir common during treatment?
The development of resistance to oseltamivir during treatment is rare.
208
What is the peak time of oseltamivir (Tamiflu), an antiviral drug for influenza?
The peak time for oseltamivir is 1-3 hours.
209
What percentage of protein binding does oseltamivir exhibit?
Oseltamivir shows 42% protein binding.
210
How is oseltamivir metabolized in the body, and does it have an active metabolite?
Oseltamivir is metabolized in the liver, and it has an active metabolite (3%).
211
What is the recommended treatment dosage for oseltamivir (Tamiflu)?
The recommended treatment dosage is 75 mg twice daily.
212
Which antiviral drug for influenza should be taken within 48 hours of symptom onset?
Both oseltamivir (Tamiflu) and zanamivir (Relenza) should be taken within 48 hours of symptom onset.
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How is zanamivir (Relenza) administered for treatment and prophylaxis?
For treatment, it is inhaled as two inhalations twice daily. For prophylaxis, it's two inhalations once daily.
214
How is baloxavir marboxil (Xofluza) taken, and when should it be administered?
It is taken as a single dose of 20 mg for 40-79 kg weight or 80 mg for 80 kg and above, and it should be administered within 48 hours of symptom onset.
215
What is the primary route of elimination for zanamivir (Relenza)?
Urine and feces are the primary routes of elimination for zanamivir.
216
What is the half-life of baloxavir marboxil (Xofluza)?
The half-life of baloxavir marboxil is 79 hours.
217
Which drug is administered as a solution for intramuscular injection and is used for RSV prophylaxis?
Palivizumab (Synagis) is administered as a solution for intramuscular injection and is used for RSV prophylaxis.
218
What is the recommended dosing schedule for palivizumab in the context of RSV prophylaxis?
Palivizumab should be administered once monthly and should commence before the RSV season, continuing until the season ends.
219
What are the common adverse effects associated with oseltamivir (Tamiflu)?
The common adverse effects include headache, nausea, and vomiting.
220
How can the occurrence of nausea while taking oseltamivir be reduced?
Nausea can be reduced by taking oseltamivir with food.
221
Why should oseltamivir be discontinued at least 2 days before administering Live Attenuated Influenza Vaccine (LAIV)?
Oseltamivir should be discontinued before LAIV to prevent it from blunting responses to LAIV.
222
After dosing with LAIV, how long should one wait before starting oseltamivir?
At least 2 weeks should elapse after dosing with LAIV before starting oseltamivir.
223
Who are the candidates for prophylactic therapy for influenza?
Candidates include family members of someone with the flu, residents of nursing homes, and high-risk members of the community.
224
When dosing family members of someone with the flu for prophylactic therapy, when should dosing begin and for how long should it continue?
Dosing should begin within 48 hours of exposure and should continue for 10 days.
225
How long can prophylactic dosing be done for residents of nursing homes or high-risk community members?
Prophylactic dosing can be done continuously for up to 42 days.
226
What are the approved indications for zanamivir (Relenza) in the context of influenza?
Zanamivir is approved for the treatment of acute uncomplicated influenza in patients at least 7 years of age and for prophylaxis of influenza in patients at least 5 years of age.
227
How does zanamivir work to provide its benefits in treating influenza?
Zanamivir, similar to oseltamivir, works by inhibiting viral neuraminidase, an enzyme required for viral replication.
228
Is zanamivir generally well tolerated?
Yes, zanamivir is generally well tolerated, but it's not recommended for patients with underlying airway disease.
229
What does the ACOG recommend regarding the use of zanamivir in pregnant women, and is there a preference?
The ACOG recommends zanamivir for pregnant women, but if there is an option, oseltamivir is preferred.
230
What are the common side effects associated with zanamivir in patients with healthy lung function?
Common side effects may include cough or throat irritation, and there have been rare reports of severe allergic reactions and neuropsychiatric effects.
231
In patients with preexisting lung disorders such as asthma or chronic obstructive pulmonary disease, what severe effects may zanamivir cause, and have there been any reported cases?
Zanamivir may cause severe bronchospasm and respiratory decline in these patients, and some have required immediate treatment or hospitalization. There have been reports of deaths, but it's unclear whether zanamivir was the sole cause.
232
Is zanamivir recommended for patients with underlying airway disease, and why?
Zanamivir is not recommended for patients with underlying airway disease due to the potential risk of causing severe bronchospasm and respiratory decline.
233
Does zanamivir have significant drug interactions, and how does it affect responses to LAIV (live attenuated influenza vaccine)?
Zanamivir is devoid of significant drug interactions. It may blunt responses to LAIV, so it should be stopped 2 days before giving LAIV and not started for 2 weeks after giving LAIV.
234
When is baloxavir marboxil (Xofluza) typically used for the treatment of influenza?
It is used in patients 12 years of age and older when symptoms have been present for 2 days or less.
235
Is baloxavir marboxil effective against both influenza A and influenza B viruses?
Yes, it is active against both influenza A and influenza B viruses.
236
In clinical trials, how did the symptom relief time for patients taking baloxavir marboxil compare to those on a placebo?
Patients taking baloxavir marboxil experienced symptom relief within 54 hours, whereas those on a placebo took 80 hours for symptom relief.
237
How does baloxavir marboxil work to combat influenza infection at a molecular level?
It is a prodrug converted into its active metabolite, baloxavir, which inhibits a protein required for viral gene transcription. This action prevents viral replication.
238
What were the adverse effects noted during clinical trials of baloxavir marboxil (Xofluza), and what were their percentages?
Adverse effects included diarrhea (3%), bronchitis (2%), and lower occurrences of nausea, nasopharyngitis, and headache (all 1%).
239
How did the adverse effects of baloxavir marboxil compare to the placebo in clinical trials?
Interestingly, the placebo group experienced higher percentages of these symptoms, with diarrhea (5%), bronchitis (4%), and headache (2%).
240
Should baloxavir marboxil be administered with certain types of substances, and if so, which ones should be avoided?
It should not be given with salts such as calcium salts, iron salts, magnesium salts.
241
How does administering baloxavir marboxil with live attenuated influenza vaccine (LAIV) impact the effectiveness of the vaccination?
Administering baloxavir marboxil with LAIV may reduce the effectiveness of the vaccination.
242
What safety concerns exist regarding the use of baloxavir marboxil, particularly in relation to age and pregnancy?
Data is currently insufficient to determine its safety during pregnancy, breastfeeding, or for use in individuals younger than 12 years of age or above 65 years of age.
243
Who is most likely to experience symptomatic Respiratory Syncytial Virus (RSV) infection?
RSV symptoms are more common in very young individuals, older adults, and people with respiratory, heart, or immune system disorders.
244
What is the impact of RSV infection in the United States, particularly in infants and young children?
In the US, RSV is the most frequent cause of lower respiratory tract disease in infants and young children, leading to between 132,000 and 172,000 hospitalizations annually, with a notable impact on child mortality.
245
What is the seasonal pattern of RSV infection, and during which months does it predominantly occur?
Similar to influenza, RSV follows a seasonal pattern, with most cases arising during the winter months.
246
What is the primary drug approved for RSV prophylaxis in the United States?
The primary drug approved for RSV prophylaxis is palivizumab (Synagis).
247
Who is Palivizumab (Synagis) primarily used to prevent RSV infection in?
Palivizumab is used to prevent RSV infection in premature infants and young children with chronic lung disease.
248
How does Palivizumab function to prevent RSV infection?
Palivizumab works by binding to an RSV surface protein, thereby inhibiting viral replication.
249
What were the findings in clinical trials regarding the hospitalization rates of premature infants receiving Palivizumab versus a placebo?
Premature infants treated with Palivizumab had a hospitalization rate of 1.8%, while those receiving a placebo had a rate of 8.1%.
250
What were the results of clinical trials for young children with chronic lung disease receiving Palivizumab?
In clinical trials, the hospitalization rate for these children was 7.9% with Palivizumab and 12.8% with a placebo.
251
When should Palivizumab dosing commence and how long should it continue for RSV infection prevention?
Dosing with Palivizumab should begin before the RSV season (typically December through March in the US) and continue until the season ends.
252
What is the approximate cost of a full season of Palivizumab treatment, and how does this relate to potential savings?
A full season of Palivizumab treatment costs about $7,000 and can save more than $50,000 by avoiding hospitalization expenses.
253
What are the main adverse effects associated with Palivizumab use?
The primary adverse effects are hypersensitivity reactions.
254
Are hypersensitivity reactions to Palivizumab common or rare?
Hypersensitivity reactions to Palivizumab are rare.
255
Can acute hypersensitivity reactions occur with the initial use of Palivizumab?
Yes, acute hypersensitivity reactions can occur with both the initial drug use and with subsequent use.
256
How often does anaphylaxis occur with Palivizumab, and is it associated with the first dose or subsequent doses?
Anaphylaxis is extremely rare (less than 1 in 100,000 cases) and only occurs with reexposure, not with the initial dose.
257
What should be done if a mild hypersensitivity reaction is experienced while using Palivizumab?
If a mild hypersensitivity reaction occurs, cautious use of Palivizumab can continue.
258
What is the recommended course of action if a severe hypersensitivity reaction takes place during Palivizumab treatment?
If a severe reaction occurs, the drug should be stopped and never used again, and severe reactions are managed with parenteral epinephrine (adrenaline) and supportive care.
