Viral infections_student.pptx

Viral Infectio ns CHAPTER 23 MATTHEW MOEHL, PHARMD Introduction and Pathophysiology Viruses are intracellular parasites Incorporates viral DNA into host’s Retroviruses have RNA which must be converted to DNA first ◦ HIV is a retrovirus Turns cell into a “virus factory” Body’s defense are antibodi...

Viral Infectio ns CHAPTER 23 MATTHEW MOEHL, PHARMD Introduction and Pathophysiology Viruses are intracellular parasites Incorporates viral DNA into host’s Retroviruses have RNA which must be converted to DNA first ◦ HIV is a retrovirus Turns cell into a “virus factory” Body’s defense are antibodies HTTPS://COURSES.LUMENLEARNING.COM/MICROBIOLOGY/CHAPTER/THE-VIRAL-LIFE-CYCLE/ HTTPS://IMGUR.COM/GALLERY/3WSWK Types of viruses Avian Influenza A (H5N1) Herpesvirus Infections ◦ Cytomegalovirus (CMV) ◦ Genital Herpes ◦ Herpes Zoster (shingles) Human Immunodeficiency Virus (HIV) Respiratory Syncytial Virus (RSV) Viral Hepatitis ◦ Hepatitis A, B, C HTTPS://WWW.NEWSCIENTIST.COM/ARTICLE/2197422GIANT-VIRUSES-HAVE-WEAPONISED-CRISPR-AGAINST-THEIRBACTERIAL-HOSTS/ Herpesviruses Herpes Simplex Virus (HSV) Fever blisters or cold sores on lips, mouth, face Genital herpes Cytomegalovirus - CMV retinitis HTTPS://WWW.CK12.ORG/BIOLOGY/VIRUSCLASSIFICATION/LESSON/VIRUS-CLASSIFICATIONADVANCED-BIO-ADV/ Drugs for Herpesvirus • Prototype: acyclovir (Zovirax) • Mechanism of action: interrupts viral DNA replication • Use(s): • Herpes simplex virus (HSV) • Genital herpes • Decreases duration and pain mintrx pharmacy • Nursing considerations: • Apply topical with gloved hand • IV form • Encephalopa thy Drugs for Cytomegalovirus (CMV) • Prototype: ganciclovir (Cytovene) • Mechanism of action: inhibits viral DNA synthesis • Use(s): • CMV • Nursing considerations: • Renal impairment • 2 BBW’s • Granulocytopenia (neutropenia), thrombocytopenia • Maintain contraceptive precautions during and 90 days after therapy valganciclovir (Valcyte) • Basically the oral version of ganciclovir • Same BBW’s • Take with high fat meal to increase absorption https://mms.mckesson.com/product/927598/Genentech-USA00004003909 Example Questions A client requires treatment for genital herpes. Why would acyclovir be prescribed? A. prevents future viral outbreaks B. decreases pain and viral shedding C. prevents superinfection D. boosts activity of other drugs A client develops Cytomegalovirus retinitis. Which is most important to consider when administering ganciclovir? A. administer on an empty stomach B. assess client’s vision after administration C. assess for reduced genital pain D. administer on a weekly basis Respiratory Syncytial Virus (RSV) Respiratory illness that is more severe in babies ◦ Bluish skin color (cyanosis) You sure that’s “just a cough?” Adults and healthy children can carry the disease with just common cold symptoms HTTPS://NEWS.GSU.EDU/2018/12/17/VACCINE-USING-MICRONEEDLE-PATCH-WITH-RSV-VIRUS-IMMUNE-STI MULATING-COMPOUND-IS-EFFECTIVE-AGAINST-RSV-STUDY-FINDS/ Drugs for RSV • Prototype: ribavirin (Virazole) • Mechanism of action: interferes with DNA and RNA replication • Use(s): • RSV in children https://medlineplus.gov/ency/imagepages/17279.htm • Nursing considerations: • BBW for severe teratogenic effects • Given via inhalation • Monitor for signs of respiratory distress such as nasal flaring Influenza (Flu) Muscle aches, pains Fatigue Fever Nausea / vomiting Headache Diarrhea Shivering **Can be deadly** HTTPS://WWW.NEWS-MEDICAL.NET/LIFE-SCIENCES/INFLUENZA-ASTRUCTURE.ASPX Drugs for Influenza • Prototype: oseltamivir phosphate (Tamiflu) • Mechanism of action: does not allow new viruses to escape cell • Use(s): • Influenza in patients > 1 year old • Nursing considerations: • May take prophylactically • Some side effects are similar to flu symptoms • Take with food to decrease GI upset A & B have vaccines Hepatitis Hepatitis A ◦ Fecal-oral route, close contact with infected person Hepatitis B ◦ Contaminated blood, other body fluids Hepatitis C ◦ Mostly same as B Cirrhosis, liver cancer, liver failure, death HTTPS://NEWSNETWORK.MAYOCLINIC.ORG/DISCUSSION/ MAYO-CLINIC-Q-AND-A-TREATING-HEPATITIS-C/ Drugs for Hepatitis • Prototype: lamivudine (Epivir) • Mechanism of action: incorporates into the viral DNA and terminates it • Use(s): • Chronic Hepatitis B • HIV (off-label) • Nursing considerations: • pancreatitis • BBW • Lactic acidosis • Musculoskeletal pain • Hepatomegaly with steatosis Example Questions A client is taking lamivudine and states he has severe upper abdominal pain. On assessment, he has guarding. What does the nurse suspect is wrong with the client? A. hepatomegaly B. pancreatitis C. lactic acidosis D. cardiomyopathy Human Immunodeficiency Virus (HIV) Retrovirus Bind to and eventually destroy CD4+ cells (e.g. T lymphocytes) ◦ CD4+ cells normally help regulate immune function… May need multiple drugs Can progress to acquired human immunodeficiency syndrome (AIDS) HIV clinical manifestations Initial phase ◦ Presents with flu-like symptoms, lasting several weeks Immune response ◦ Decrease in viral reproduction ◦ Asymptomatic, but infectious Immune system damaged ◦ Increased viral reproduction Illness progresses to AIDS ◦ Once viral load reaches high level ◦ Serious opportunistic infections HTTPS://AIDSINFO.NIH.GOV/UNDERSTANDING-HIV-AIDS/ GLOSSARY/3387/HIV-PROGRESSION HTTP://I-BASE.INFO/GUIDES/TESTING/VIRAL-LOAD Pre-Exposure Prophylaxis (PrEP) … “a way for people who do not have HIV but are at very high risk of getting HIV to prevent HIV infection by taking a pill every day.” – CDC.com. That pill is Truvada (tenofovir and emtricitabine) When taken daily, lowers risk of HIV infection: ◦ From sex by about 99% ◦ From injection by about 74% If not taken consistently, not as effective. Only protects against HIV… need other protection for other STD’s. HTTPS://WWW.CDC.GOV/HIV/RISK/PREP/INDEX.HTML Nucleoside Reverse Transcriptase Inhibitors (NRTIs) • Prototype: zidovudine (AZT, Retrovir) • Mechanism of action: incorporates into viral DNA and terminates • Prevent step 3-4 • Use(s): • Prevent HIV transmission from mother to fetus • Nursing considerations: • BBW • Granulocytopeni a, pancytopenia • Lactic acidosis, hepatomegaly Nonnucleoside Reverse Transcriptase Inhibitors (NNRTIs) • Prototype: efavirenz (Sustiva) • Mechanism of action: similar to NRTI. Have synergy. • Prevent step 3-4 • Use(s): • HIV • Nursing considerations • Not for patients with hepatic impairment • Stevens-Johnson syndrome • CNS effects • Take at night Example Questions A client is receiving zidovudine for treatment of HIV. Which symptom may indicate the client is developing lactic acidosis? A. low granulocyte count B. severe upper abdominal pain A client has been taking efavirenz for about 1 week. For which delayed hypersensitivity reaction should the nurse educate the client? A. CDAD B. neutropenia C. musculoskeletal pain C. anaphylaxis D. disulfiram reaction D. Stevens-Johnson syndrome Protease Inhibitors (PIs) • Prototype: saquinavir mesylate (Invirase) • Mechanism of action: prevents viral maturation • Prevent step 4-5 • Use(s): • HIV • Nursing considerations: • Must monitor for QT prolongation • Take within 2 hours of a meal Integrase Strand Inhibitors (INSTIs) • Prototype: raltegravir (Isentress) • Mechanism of action: blocks enzyme HIV integrase, which would normally make more viruses • Use(s): • Resistant HIV • Nursing considerations: • Only for strains resistant to multiple antiretroviral drugs Fusion Protein Inhibitors • Prototype: enfuvirtide (Fuzeon) • Mechanism of action: prevents HIV from entering cell • Prevents step 1 • Use(s): • HIV • Nursing considerations • Given as subcutaneous injection • Must have already received other antiretroviral agents CCR5 Antagonist • Prototype: maraviroc (Selzentry) • Mechanism of action: prevents HIV from entering cell • Prevents step 1 • Use(s) • HIV • Nursing considerations • Not for patients with low kidney function • BBW • May cause hepatotoxicity and/or allergy symptoms 1 month into treatment Example Question Which drug is given subcutaneously for treatment of HIV? A. efavirenz B. raltegravir C. enfuvirtide D. maraviroc The End