Anti-Virals PDF

ANTI VIRALS   Intracellular organism that must reside within a living host to survive and reproduce  Enter healthy cells and use their DNA and RNA to generate more viruses  Growth cycle depends on the host cell enzymes and cell substrates f...

ANTI VIRALS   Intracellular organism that must reside within a living host to survive and reproduce  Enter healthy cells and use their DNA and RNA to generate more viruses  Growth cycle depends on the host cell enzymes and cell substrates for viral replication VIRUS  Live and reproduce when they are within living cells → Influenza, herpes virus infections, and viral hepatitis infections → Viral infection usually can be detected only after the virus has replicated itself  1. Influenza (flu)  Highly contagious viral infection that affects the nose, throat, and lungs  Three antigen types:  A – causes a moderate to severe infection  B – mild illness in children  C – very rare in humans VIRAL  Transmitted easily via droplets during coughing, sneezing, or talking  Droplets enter into the respiratory tract of the unaffected person and INFECTIONS begin replication 24 hours before the appearance of symptoms  Usually has an abrupt onset with the first symptoms being headache, fatigue, and myalgia  Other symptoms – sore throat, nonproductive cough, watery nasal discharge, weakness, red watery eyes, chills, and photophobia  Diagnostic tests include throat swabs, nasal swabs, or nasal aspiration  2. Herpesviruses  Spread by intimate sexual contact or an infected mother can transmit virus  Large viruses that cause infections to infant during childbirth VIRAL  Types: → Both HSV 1 and 2 are capable of causing recurrent infections INFECTIONS  Herpes simplex type 1 (HSV-1) → Both can replicate in the mucous  Usually associated with cold sores membranes and skin of the (vesicular lesions) which grow in oropharynx or genitalia neurons → Virus is transmitted by contact with  Capable of latency (maintains infectious lesions or secretions disease potential without signs and symptoms) → s/sx include eruption of small pustules and vesicles, fever,  Spread by oral secretions headache, malaise, myalgia, tingle,  From the mouth, virus spreads to itching and pain in the genital area genital area by oral sex or poor handwashing  Herpes simplex type 2 (HSV-2)  Associated with vesicular lesions and small ulcerations on the genitalia (genital herpes)  Remains dormant by traveling through the peripheral nerves to the sacral dorsal root ganglia (can continue to replicate)  2. Herpesviruses  Epstein-Barr virus (HSV-4 or VIRAL  Types: EBV)  Commonly causes infectious INFECTIONS  Varicella-zoster viruses (HSV- 3) known as chickenpox and mononucleosis  Manifested by fever, tonsillitis, shingles and enlarged lymph nodes in  Chickenpox is highly the neck contagious that causes  Resides in the lymphocytes, generalized pruritic vesicles epithelial cells, and muscles and fever cells and has a latency period  Shingles is a painful vesicular  Cytomegalovirus (HHV-5 or rash that can remain dormant CMV) – very common in nerve cells infectious dse  Can recur in a person who has previously been infected with  Do not require treatment chickenpox who has become unless immunocompromised older or developed a  May lead to fatal pneumonia weakened immune system – or blindness virus that resides on the nerves is reactivated resulting  Transmitted via body fluids in rash formation as well as (saliva or urine) by kissing, fever, malaise, and myalgia sexual contact, or sharing food; or by a pregnant woman to fetus  3. Hepatitis B (HBV)  Serious liver infection caused by hepatitis B virus  Transmitted via needlestick, intimate sexual contact, or childbirth VIRAL  Found in all body fluids including blood, INFECTIONS semen, vaginal fluid  s/sx include anorexia, vomiting, diarrhea, jaundice, malaise, and myalgia   Used to prevent or delay the spread of a viral infection  Inhibit viral replication by interfering with viral nucleic acid synthesis in the cell  Classifications ANTIVIRAL NON-  NON-CLASSIFIED ANTIVIRALS HIV DRUGS  TOPICAL ANTIVIRALS  NEURAMINIDASE INHIBITORS  GAMMA GLOBULIN (IMMUNE GLOBULIN)  PURINE NUCLEOSIDE   Amantidine HCl (PO)  Cidofovir (IV)  For Type A influenza  For CMV retinitis especially in patients with AIDS  Side effects  CNS effects i.e. insomnia,  WOF kidney damage depression, anxiety, confusion,  Foscarnet (IV) ataxia, orthostatic hypotension, weakness, dizziness, slurred  For herpes virus (HSV-1 and speech; NONCLASSIFIED  GI disturbances i.e. anorexia, HSV-2, VZV) and CMV retinitis especially in patients with HIV- ANTIVIRALS nausea, vomiting, and diarrhea AIDS  Rimantadine HCl (PO)  WOF kidney damage and hyperphosphatemia  For Type A influenza  Telbivudine, adefovirdipivoxil,  SEs occur less often entecavir (PO)  Influenza virus vaccine (IM)  For chronic hepatitis B virus  For prophylaxis against influenza types A and B  → Treats herpes simplex viruses  Idoruxidine  Penciclovir TOPICAL  For recurrent herpes labialis (cold sores) ANTIVIRALS  Trifluridine  For keratoconjunctivitis   Group of drugs that decrease the release of the virus from infected cells thus decreasing viral spread and shortening the duration of flu symptoms  Both should be taken within 48 hours of flu symptoms  Inhibit the activity of neuraminidase (viral glycoprotein) and effective against types A and B influenza viruses NEURAMINIDASE  Zanamivir (INH) INHIBITORS  For influenza A and B and H1N1 influenza  Oseltamivir Phosphate (PO)  For uncomplicated acute influenza types A and B  May be taken with or without food  SEs: nausea and vomiting   IgG – rich in antibodies found in the blood  Provides a passive form of immunity to a virus by blocking the penetration of the virus into the host cell GAMMA  Administered during the early infectious stage of an illness to prevent a viral invasion in the body GLOBULIN  Human immune globulin is administered IM (Gamastan) (IMMUNE GLOBULIN)  Single dose injection protects for approx 2 to 3 weeks and may be repeated following the first dose  May be given IV for patients who need an immediate increase in IgGs (Gamimune N)   Effective in interfering with the steps of viral nucleic acid DNA synthesis  Effective in combating herpes simplex viruses HSV 1&2, shingles and chicken pox, and CMV  Ribavirin (INH, PO)  For RSV in children  For other respiratory infections caused by influenza A and B in older adults PURINE  For hepatitis C  Acyclovir (PO, IV) NUCLEOSIDE  Introduced as an antineoplastic and later found to be effective against herpesvirus HSV 2 and HSV 1, herpes zoster, CMV  Probenecid can increase the effect of acyclovir  Aminoglycoside or amphoterecin B with acyclovir —> increased nephrotoxicity  Famciclovir (PO)  developed before valacyclovir and is equally effective as acyclovir  For herpes zoster and HSV 1   Varicella-zoster IG (IM)  Post exposure prophylaxis of varicella zoster  Ganciclovir sodium (IV)  For CMV systemic infection in immunocompromised patients  Valacyclovir (PO) Effective against VZV causing herpes zoster and recurrent genital PURINE  herpes NUCLEOSIDE  Offers greater decrease in pain and an increase in healing compared with acyclovir  Monitor kidney function and increase water intake  Valganciclovir (PO)  For CMV-infected cells of retinitis in AIDS patients  Inhibits viral DNA synthesis  WOF leukopenia, thrombocytopenia, BM depression, aplastic anemia  HIV is an RNA retrovirus  Symptoms may be mild to severe: fever, fatigue, pharyngitis, myalgia or arthralgia, lymphadenopathy,  Unable to survive and replicate unless it is inside headache, night sweats a living human cell  Can be experienced 2-12 weeks after an HIV exposure  Destroys CD4+ T cells (helper T cells or CD4+T  May be mistaken for a flulike illness → few people are lymphocytes) which play a critical role in the diagnosed during this time human immune response through recognition of  Time delay from infection to a positive HIV test result infectious and neoplastic processes averages 10 to 14 days even 3 to 4 weeks (WINDOW PERIOD) → test must be repeated in 3 months  Results in immune deficiency  High viral load would support HIV diagnosis (HIV RNA  CD4 cell count is an indicator for immune function in quantitative test) → >10,000c/mL and usually those with HIV >100,000c/mL  Normal CD4 counts range from 800-1200cells/mm3  Becomes AIDS with a CD4 count 1000copies/mL  Others (accidental needle injury, artificial at delivery, PROM, hepatitis C virus coinfection, insemination with donated semen, and organ preterm gestation, and vaginal delivery transplant) HIV-AIDS  Laboratory Testing is important for initial patient evaluation upon entry to care, during ff up evaluation for those not on ART, and before and after initiation or modification of ART to assess for immunologic and virologic efficacy of treatment  Important laboratory tests:  CD4 T-cell count: more stable indicator of immune system  Plasma HIV RNA quantitative assay or VIRAL LOAD – key goal of therapy is to achieve and maintain a viral load below the limits of detection (