Antiviral Agents Flashcards
Which viruses respond to Antiviral Therapy?
- Influenza A and some respiratory viruses
- Herpes viruses
- Cytomegalovirus (CMV)
- Human Immunodeficiency Virus (HIV) that causes Acquired Immune Deficiency Syndrome (AIDS)
- Hepatitis B and C
Characteristics of Viruses
- Cannot replicate on their own
- Must attach to and enter a host cell
- Uses the host cell’s energy to synthesize protein, DNA, and RNA
- Difficult to kill because they live INSIDE our cells
- Any drug that kills a virus may also kill our cells
Considerations for Antivirals
In Children
- More severe reactions expected
- No proven safety for many; extreme caution should be used
- Doses should be calculated by WEIGHT
- Monitor closely
Considerations for Antivirals
In Adults
- Antibiotics will NOT work for viral infections
- Drugs DO NOT CURE the disease
- Caution in pregnancy
- Advise women of childbearing age to use contraceptives
Considerations for Antivirals
In Older Adults
- More susceptible to adverse effects; monitor closely
- Hepatic/renal dysfunction may be worsened by these medications
- Dose may need to be lowered
Common Respiratory Viruses
- Influenza A
- Influenza B
- Respiratory Syncytial Virus (RSV)
Agents for Influenza and Respiratory Viruses
Drug Names and Indications
- Amantadine: Influenza A and West Nile Virus
- Oseltamivir: Influenza A and B (shortens severity if taken early)
- Peramivir: Acute influenza
- Rimantadine: Influenza A
- Zanamivir: Influenza A and B (inhaled medication)
Agents for Influenza and Respiratory Viruses
Mechanism of Action
Prevents viral replication
Agents for Influenza and Respiratory Viruses
Contraindications
Absolute:
* Allergy
* Renal Impairment
* Pregnancy and lactation
Agents for Influenza and Respiratory Viruses
Adverse Effects
- CNS: Headache, insomnia
- GI: nausea
- CV: Orthostatic hypotension (because of effect on dopamine –> vasodilation)
- GU: Urinary Retention
- Peramivir - associated with Stevens-Johnson Syndrome
Agents for Influenza and Respiratory Viruses
Assessment
History:
* Allergy
* Renal Impairment
* Pregnancy or lactation
Physical:
* CNS: Orientation, reflexes
* Vital Signs
* Urinary Output
* Skin
Labs:
* Renal and Hepatic function tests
Agents for Influenza and Respiratory Viruses
Nursing Conclusions/Diagnoses
- Impaired Comfort (r/t GI, CNS, or GU effects)
- Altered Sensory Perception (r/t CNS effects)
- Knowledge deficit
Agents for Influenza and Respiratory Viruses
Implementation/Patient Teaching
- Hydrate well
- Change positions slowly
- Avoid driving until CNS and hypotension effects are known
- Start the drug regimen AS SOON after exposure to the virus as possible
- Administer FULL course of the drug
Agents for Herpes and Cytomegalovirus (CMV)
Drug Names and Indications
“-clovir”
* Acyclovir: Genital herpes, cold sores, chicken pox, shingles
* Ganciclovir: Cytomegalovirus (CMV)
* Valacyclovir: Genital herpes, cold sores, shingles
* Valganciclovir: treat and prevent cytomegalovirus (CMV)
Agents for Herpes and Cytomegalovirus (CMV)
Mechanism of Action
- Inhibits viral DNA replication
Agents for Herpes and Cytomegalovirus (CMV)
Contraindications
Absolute:
* Allergy
* Pregnancy (HIGHLY toxic)
Relative:
* Lactation
* Renal disease
* CNS disorders (MS, epilepsy, Alzheimer’s, stroke, etc.)
Agents for Herpes and Cytomegalovirus (CMV)
Adverse Effects
- GI: Nausea, vomiting
- Headache
- Rash
- Hair loss
- Paresthesias
- Neuropathy
- Renal Dysfunction
Agents for Herpes and Cytomegalovirus (CMV)
Drug Interactions
- Nephrotoxic Drugs
- Zidovudine (HIV drug)
Agents for Herpes and Cytomegalovirus (CMV)
Assessment
History:
* Allergy, pregnancy, lactation, renal disease, CNS disorders
Physical:
* CNS: Orientation, reflexes
* Skin: Color, temperature, lesions
Labs:
* Renal function tests
Agents for Herpes and Cytomegalovirus (CMV)
Implementation/Patient Teaching
- Adminsiter drug AS SOON AS possible after diagnosis
- Ensure good hydration
- Administer complete course of treatment
- Wear protective gloves when applying drug topically
- Warn patient about GI upset, nausea, vomiting
- Monitor renal function tests periodically during treatment
- Avoid sexual intercourse during outbreak
- Avoid driving w/CNS effects
- Patient teaching: infection is not curable, just managed with drug therapy
Agents for HIV and AIDS
ALL the Drug Classes
- Protease Inhibitors
- Nonnucleoside Reverse Transcriptase Inhibitors
- Nucleoside Reverse Transcriptase Inhibitors
- Fusion Inhibitors
- CCR5 Coreceptor Antagonists
- Integrase strand transfer inhibitors
Typically on 3 different agents at the same time. Work to SLOW the progress of the infection
Nonnucleoside Reverse Transcriptase Inhibitors: NNRTIs
Drug Names
Delavirdine
Efavirenz
Nevirapine
Nonnucleoside Reverse Transcriptase Inhibitors: NNRTIs
Mechanism of Action
- Bind DIRECTLY to HIV Reverse Transcriptase
- Block both RNA- and DNA- dependent DNA polymerase activities
Nonnucleoside Reverse Transcriptase Inhibitors: NNRTIs
Contraindications
Absolute:
* Allergy
* Pregnancy and Lactation
Nonnucleoside Reverse Transcriptase Inhibitors: NNRTIs
Adverse Effects
- Mostly GI effects: abdominal pain, N/V, constipation, diarrhea
- Dry Mouth
- Dizziness, blurred vision, headache
- Flu-like symptoms
Nonnucleoside Reverse Transcriptase Inhibitors: NNRTIs
Drug Interactions
Numerous
Nucleoside Reverse Transcriptase Inhibitors: NRTIs
Drug Names
Abacavir
Emtricitabine
Lamivudine
Tenofovir
Zidovudine
Nucleoside Reverse Transcriptase Inhibitors: NRTIs
Mechanism of Action
- Compete with naturally occuring nucleosides within the cell that the virus would use to build the DNA chain.
- Inserts into the viral DNA as a STOP CODON
Preferred method for pregnant patients
Nucleoside Reverse Transcriptase Inhibitors: NRTIs
Contraindications
Absolute:
* Allergy
* Lactation
Caution:
* Hepatic dysfunction
* Renal impairment
* Bone Marrow Suppression
Nucleoside Reverse Transcriptase Inhibitors: NRTIs
Adverse Effects
- Hypersensitivity
- Pancreatitis
- Hepatomegaly (abd. pain, Inc. liver enzymes)
- Neurological problems
- Bone Marrow Suppression
with Flu symptoms/any sensitivity symptoms –> STOP drug immediately
Nucleoside Reverse Transcriptase Inhibitors: NRTIs
Drug Interactions
- Numerous
Don’t mix with other antivirals
w/immunosuppressants = monitor closely
Protease Inhibitors
Drug Names
“-navir”
Darunavir
Fosamprenavir
Lopinavir
Ritonavir
Tripanavir
