intro to antimicrobial therapy and antiviral agents

acyclovir (zovirax)

•MOA: Inhibits viral replication by suppressing synthesis of viral DNA

•Indications

•Topical for HSV1

•PO for HSV2 and VZV

•IV for either in immunocompromised patients

•Adverse effects

•Can take without regards to meals

•Phlebitis and inflammation with IV therapy

•Nephrotoxicity (elevated Crt and BUN)

•Neurotoxicity (agitation, delirium, tremors)

•Nursing considerations

•Viral resistance to therapy

•Monitor renal function & fluid status

•Monitor neuro status

•Only decreases s/s in genitalis; avoid sexual contact when lesions present and use protection

•Use finger cot/rubber glove with topical

•Valcyclovir represents a more effective way to get acyclovir in the body

Cytomegalovirus (CMV)

is very common and is transmitted through direct contact with infected bodily fluids, including saliva, urine, blood, tears, breast milk, and semen. Manifestations are usually only seen in immunocompromised patients (e.g. HIV, chemotherapy, immunosuppressive agents).

Ganciclovir (Cytovene)

•MOA: Inhibits viral replication by suppressing synthesis of viral DNA and incorporating it into the chain causing chain termination

•Indications

•Prevention & treatment of CMV infection in immunocompromised pts

•Adverse effects

•Granulocytopenia

•Thrombocytopenia

•Teratogenic

•Nursing considerations

•Monitor complete blood count for changes in WBC and PLT

•Coadministration with G-CSF; administer PO with food

Education on contraception

viral hepatitis

Damage to the liver by the hepatitis virus can be seen with local and systemic manifestations. Manifestations can be acute or chronic.

All types of the hepatitis virus can cause acute hepatitis, whereas only HBV, HCV, and HDV can cause chronic hepatitis.

interferon alfa

•MOA

•Blocks viral entry into cells

•Blocks synthesis of viral messenger RNA and viral proteins

•Blocks viral assembly and release

•Indicated for both HCV and HBV

•Administration

•Conventional therapy SQ/IM 3 times/week

•Long acting therapy SQ once/week

•Adverse effects

•Most common are flu-like s/s

•Neuropsychiatric

•Bone marrow suppression with long term

•Nursing considerations

•Acetaminophen PRN for flu-like s/s

•Monitor mental status

•Monitor complete blood count

Monitor hepatitis s/s and liver enzymes

Simeprevir (Olysio)

•Not indicated as monotherapy - only used in combination with other agents

•Protease inhibitor class medication

•MOA - Inhibit viral protease, enzyme needed for HCV replication

•Adverse effects

•Most common are HA, nausea, and fatigue

•Hepatic injury

•Photosensitivity

•Rash

•Nursing considerations

•Monitor hepatitis s/s and liver enzymes

•Caution with sulfa allergies and amiodarone

Daclatasvir (Daklinza)

•NS5A inhibitor class medication as part of anti-HCV regimens

•MOA - Inhibit NS5A proteins that is necessary for replication and assembly to prevent formation of HCV

•Adverse effects

•Most common are HA and fatigue

•Possible anemia

•Nursing considerations

•Monitor hepatitis s/s and liver enzymes

•Due to numerous drug interactions, educate patient on not starting new medications without counseling first

Ribavirin (Rebetol)

•Never used as monotherapy - only effective when combined with interferon alfa

•MOA - Unclear, but increases patient response to interferon alfa

•Adverse effects

•Interferon alfa s/s

•Hemolytic anemia

•Fetal injury

•Nursing considerations

•Monitor mental status

•Monitor complete blood count

•Monitor hepatitis s/s and liver enzymes

•Extended use of contraception due to prolonged half-life

Lamivudine (Epivir)

•Nucleoside analog used to treat HBV

•MOA suppresses HBV replication by inhibiting viral DNA synthesis

•Adverse effects

•Lactic acidosis

•Pancreatitis

•Hepatomegaly

•Nursing Considerations

•Give lowest dose possible to patients who is HIV positive

•Monitor amylase and lipase

•Monitor ABGs

•Educate patient to take medication as prescribed

Oseltamivir (Tamiflu)

•MOA - inhibits neuraminidase to prevent viral replication and prevents newly formed viral particles from spreading to other cells

•Adverse effects

•Generally well-tolerated but better if taken with food

•Most common is N/V

•Hypersensitivity & neuropsychiatric s/s are rare

•Nursing considerations

•Rapid flu testing possibly before to confirm diagnosis

•Carefully assess for vaccination history and onset of s/s (within 48 hrs)

•Educate patients to monitor allergic reaction s/s, particularly with integumentary system

Baloxavir Marboxil (Xofluza)

•MOA- PO Endonuclease inhibitor that is converted to to baloxavir which inhibits protein activity for viral gene transcription.

•Adverse Effects

•Uncommon

•Don’t administer with salts (calcium, iron, magnesium)

•Nursing Considerations

•Administration with the LAIV may decrease the effectiveness of the vaccine

•Take within 48 hours of symptom onset

Palivizumab (Synagis)

•IM monoclonical antibody indicated for preventing RSV infection

•MOA-antibody binds to surface protein on RSV and prevents replication.

•Adverse Effects

•Hypersesnstivity reactions

•Anaphylaxis (rare)

•Nursing Considerations

•Use appropriate IM administration techniques

•Use caution with mild hypersensitivity reactions

•Discontinue with severe hypersensitivity reactions

Abacavir (Ziagen)

•PO Nucleoside reverse transcriptase inhibitor (NRTI) class antiviral medication

•MOA - NRTI that inhibit HIV replication by suppressing synthesis of DNA through acting as substrates for reverse transcriptase

•Adverse effects

•Lactic acidosis & hepatic steatosis r/t mitochondrial toxicity

•Possible evidence for increased risk for MI

•Hypersensitivity

•Nursing considerations

•Genetic testing for HLA-B*5701

•Monitor cardiac and LA s/s

•Use of safe practices to prevent transmission

•Other first-line NRTI include lamivudine, tenofovir, & emtricitabine

Efavirenz (Sustiva)

•PO Non-nucleoside reverse transcriptase inhibitor (NNRTI) class antiviral medication

•MOA - NNRTI that inhibit HIV replication by suppressing synthesis of DNA through binding to active center of reverse transcriptase enzyme

•Adverse effects

•CNS symptoms are common

•Rash

•Teratogenicity

•Nursing considerations

•Numerous drug interactions, including those for HIV

•Taking med at hs on empty stomach can reduce CNS symptoms

•Educate on CNS symptoms and rash

Darunavir (Prezista)

•PO Protease inhibitor class antiviral medication

•MOA – dorunavir inhibits protease, an enzyme needed for HIV virion maturation, leaving virus immature and noninfectious; ritonavir helps boost lopinavir’s effects as well as being combined with other medications

•Adverse effects

•Most common is N/D/HA

•Rash due to sulfa drugs

•Hyperglycemia occurs much less compared to other PIs

•Lipodystrophy and hyperlipidemia

•Can increase serum levels of other antiretrovirals (abacavir)\

•Drug interactions with HCV medications and antidysrhythmic

•Nursing considerations

•Virus less resistant to drug combination

•Stable at room temperature for short-term; put in refrigerator for long-term

Educate patients on lipid control and low cholesterol diet

Raltegravir (Isentress)

•PO Integrase strand transfer inhibitor (INSTI) class antiviral medication

•MOA - inhibit integrase, an enzyme needed for HIV replication, by preventing insertion into host DNA

•Adverse effects

•Generally well tolerated

•Elevated liver enzymes

•Skin hypersensitivity reactions rare

•Viral medication resistance more common

•Nursing considerations

•Assess for hepatic injury and trend LFT

•Instruct patients to report skin manifestations and stop med immediately

Other first-line INSTI is dolutegravir

Enfuvirtide (Fuzeon)

•SQ fusion inhibitor class antiviral medication indicated for infections resistant to other initial treatments

•MOA – Blocks HIV entry into CD4 T cells by preventing fusion of the HIV lipid bilayer with the CD4 T cell’s lipid bilayer through binding of medication to glycoprotein in HIV envelope

•Adverse effects

•SQ injection site reactions

•Pneumonia s/s

•Hypersensitivity reactions

•Nursing considerations

•Medication administration technique

•Monitor respiratory and integumentary systems

Maraviroc (Selzentry)

•PO CCR5 antagonist class antiviral medication indicated for infections resistant to other initial treatments

•MOA - CCR5 antagonist that blocks HIV entry into CD4 T cells by binding with CCR5, a co-receptor needed for entry

•Adverse effects

•Hepatic injury

•Possible increased risk for CV events, including MI

•Nursing considerations

•Educate and assess for liver injury

•Assess CV status

•CCR5 tropism assay is performed first to determine if use is appropriate

Cabotegravir/Rilpilvirine (Cabenuva)

•indicated as a complete regimen for the treatment of HIV-1 infection in adults and adolescents 12 years of age and older

•Single dose gluteal IM injection given once monthly every month or every 2 months.

•MOA: inhibits HIV integrase by binding to the integrase active site and blocking the strand transfer step of retroviral deoxyribonucleic acid (DNA) integration that is essential for the HIV replication cycle

•Adverse Reactions:

•Hypersensitivity reactions

•Post injection reactions

•Hepatotoxicity

•Depressive disorders

•Nursing Considerations:

•Administer each injection at separate gluteal injection sites

•A complete dose requires 2 injections

•Allow 15 minutes for the medicine to become room temperature.

•May remain in a syringe for 2 hours.

•Patient education on adverse reactions and signs and symptoms

Emtricitabine and Tenofovir Alafenamide (Descovy)

•PO combination NRTI and NNRTI for the prevention and treatment of HIV 1

•MOA-same as NRTI and NNRTI

•Adverse Effects

•Nausea

•Diarrhea

•Nursing Considerations

•Educate patients report AE to provider

•Educate patient on adherence

•Can not use alone for a patient with a positive status.

HIV tests every 6 months

Nirmatrelvir & ritonavir (Paxlovid)

●Oral therapy indicated for symptomatic, nonsevere COVID-19 infection with risk factors for the development of severe COVID-19 infection

●MOA - Nirmatrelvir acts as a protease inhibitor, with ritonavir increasing nirmatrelvir's plasma concentrations via metabolism inhibition

●Adverse Effects

○Hypertension

○Diarrhea, impaired or altered sense of taste

○Myalgia

○Rebound COVID-19 infection

●Nursing considerations

○Patient education on medication regimen (twice daily x 5 days) and adherence

○Numerous drug interactions; thoroughly assess medication usage during the patient interview

○Risk of HIV resistance if a patient has an uncontrolled or undiagnosed infection

Molnupiravir (Lageviro)

●Oral therapy indicated for symptomatic, nonsevere COVID-19 infection with risk factors for development of severe COVID-19 infection

●MOA - Once metabolized and phosphorylated, it is incorporated into viral RNA polymerase resulting in viral genome errors and replication inhibition

●Adverse Effects

○Erythema, rash, urticaria

○Hypersensitivity, including anaphylaxis, angioedema

●Nursing considerations

○Alternative outpatient option for those who cannot take Paxlovid

○Patient education on medication regimen (twice daily x 5 days) and adherence

○Not commercially available; current use is under EUA from AmerisourceBergen

○Capsules can be administered with or without food; do not crush, open, or break

Remdesevir (Veklury)

●IV SARS-CoV-2 nucleotide analog RNA polymerase inhibitor class medication

●Indicated for COVID-19 infection requiring hospitalization & supplemental oxygen in adults and pediatric patients aged 12 or older and weighing at least 40 kg

●MOA - inhibits RNA polymerase, which is necessary for viral replication, by acting as an ATP analog which results results in delayed chain termination during replication

●Adverse Effects

●Potentially severe bradycardia

○Elevated ALT and AST levels

○Hypersensitivity reactions resulting in anaphylaxis, angioedema, rash, etc.

○Prolonged prothrombin time

●Nursing considerations

○Monitor CMP and RUQ s/s

○Although unlikely, monitor renal function for impairment for duration of therapy

○Discontinue infusion and provide appropriate interventions if hypersensitivity reactions occur

BNT162b2 (Pfizer-BioNTech COVID-19 Vaccine)

●Two-dose IM mRNA vaccine for prevention of symptomatic COVID-19 at or after day 7 following the second dose (95% efficacy)

●MOA - After delivery of lipid nanoparticle, RNA is translated to express full-length spike protein to elicit a systemic immune response to produce immunity

●Adverse Effects

○Injection site soreness

○Fever, chills, fatigue, headache, & lymphadenopathy within 24-48 hours

○Anaphylaxis, very rarely; milder allergic reactions

●Nursing considerations

○Patient education, including duration of protection and time between doses (21 days)

○Careful preparation to maximize doses per vial and appropriate amount of diluent (1.8 mL of NS; 0.3 mL administered per dose)

○Once reconstituted, must be used within 6 hours

○Intramuscular injection soreness can be treated with OTC analgesics

○Monitor patients for 15 minutes post-administration

mRNA-1273 (Moderna COVID-19 Vaccine)

●Two-dose IM mRNA vaccine for prevention of symptomatic COVID-19 at or after day 7 following the second dose (94.1% efficacy)

●MOA - After delivery of lipid nanoparticle, RNA is translated to express full-length spike protein to elicit a systemic immune response to produce immunity

●Adverse Effects

○Injection site soreness

○Fever, chills, fatigue, headache, myalgia, arthralgia

○Anaphylaxis, very rarely; milder allergic reactions also reported

●Nursing considerations

○Patient education, including duration of protection and time between doses (28 days)

○Careful preparation to maximize doses per vial

○Once vial is punctured, must be used within 6 hours

○Intramuscular injection soreness can be treated with OTC analgesics

Monitor patients for 15 minutes post-administratio