Monica - Week 5 - Exam 2 Flashcards
what are the 3 characteristics of viruses?
- smaller than bacteria
- transfers via skin or mucous membranes (sexual contact, blood, organ transplant
- replicates inside host cell (fuses to outer membrane
what is cell-mediated immunity?
- non-specific immune response
- neutrophils, macrophages respond
- lymphocytes release cytokines
what do cytokines stimulate?
stimulate immune system to attack → T/B cells
what is humoral immunity?
- specific immune response
- production of antibodies
- attack and destroy viruses
- *body remembers
what is the capsid of the virus structure?
- the capsid contains contains the virus’ genetic material (DNA and RNA)
what is the viral envelope?
the viral envelope is made from fatty lipid molecules taken from cells in the host
what is the surface proteins of virus structure?
these help the virus recognize and bind to cells in the host organism
what is the virus genetic material (DNA/RNA)?
the virus’ genetic material contains the instructions for making new copies of the virus
what are the stages of viral infection?
- virus attaches to a cell
- virus penetrates cell membrane and injects nucleic acid (DNA or RNA) into cell
- viral nucleic acid replicates using host cells (our cells)
- new viral nucleic acids are packaged into viral particles and released from the cell ***host cell may be destroyed in the process
where does herpes virus “live”?
remains latent, non-replicating state in sensory or autonomic nerve root ganglia
when does replication of herpes virus occur?
replication from immunosuppression, physical or emotional distress (fevers, surgery) → may cause reappearance of lesions
is there a cure for herpes viruses?
no cure
how is herpes virus spread?
direct physical contact with the infected person
- can be dormant
- may be asymptomatic
what is herpes simplex virus 1?
mucocutaneous herpes - eyes, mouth, lips
what is herpes simplex virus 2?
genital herpes
t/f: for HSV1 and HSV2, people can contract even when person doesn’t have symptoms present (sores)
TRUE
what is human herpes virus (HHV)-3?
varicella zoster (chicken pox) herpes zoster (shingles)
what can meds for herpes virus do?
not cure, but can ↓ severity and frequency of outbreaks
T/F: herpes zoster is common in adults > 50 y/o but can occur in 20/30 y/o as well.
TRUE
how can varicella zoster be transmitted?
DIRECT CONTACT + INDIRECT CONTACT - contact (touching blisters) - airborne (breathing) - droplet (sneezing, coughing) INDIRECT - contaminated items (linens/clothing)
when can the varicella zoster virus be spread? contagious?
can spread in 1 - 2 days before rash; people w/o visible blisters can still infect
when does transmission of varicella zoster stop?
stops when blisters dry and become crusted
T/F: varicella zoster can reactivate and cause shingles
TRUE
who gets herpes zoster?
those with a previous history of chicken pox (varicella zoster)
the active shingles virus can cause _______ in someone who has never contracted the virus
chicken pox (varicella zoster) ***can't pass shingles to shingles
how is herpes zoster transmitted?
transmitted via direct contact with blisters only
**if asymptomatic → no transmission occurs
who at risk for developing herpes zoster?
adults > 50, weakened immune system, immunosuppression therapy (corticosteroids/steroids)
how long does the blister rash of shingles usually last?
lasts 2 - 4 weeks
what are the complications of shingles?
post-herpetic neuralgia (after herpes pain; burning; can last months or years) disseminated zoster ( spreads to other areas of the skin)
when shingles becomes disseminated what other precaution needs to be put into effect?
airborne precaution - travels like dust
is there a vaccine for shingles?
yes - q 5 years, ↓ 50% may not get it
T/F: 10 - 20% of people may have shingles if you’ve had chicken pox
TRUE
how do antivirals work?
work by inhibiting viral replication; synergism (work wiith) with host’s immune system to suppress or eliminate virus
T./F antivirals work best in an immune-competent system
TRUE; not same efficiency in immunosuppressed
do antivirals guarantee full eradication of the virus?
no; may not fully eradicate a virus; helps the immune system kick in and control virus; suppresses replication
what forms does acyclovir come in?
PO, buccal, IV, and topical forms
what is acyclovir used for?
recurrent HSV-1, HSV-2, shingles, and varicella zoster
how does acyclovir work?
interferes with viral DNA synthesis; inhibits viral replication. `
T/F: acyclorvir is the drug of choice as antiviral
TRUE
what is the adverse effect of acyclovir PO?
crystalluria
what is the adverse effect of acyclovir topical?
S-J syndrome
what is important teaching for acyclovir?
encourage adequate hydration → crystaluria
what does buccal acyclovir treat?
treats cold sores
what should be assessed with acyclovir?
color and clarity of urine; labs (creatinine + BUN) → kidney function
what is the ultimate outcome with acyclovir?
- crusting over and healing of skin lesion
- decreases frequency and severity of recurrences (prophylaxis)
- cessation of pain
what is the action of oseltamivir and zanamivir?
inhibits neuraminidase enzyme needed for replication
what does neuraminidase enzyme do?
allows virus particles to escape and infect others
what are oseltamivir and zanamivir indicated for?
- effective against influenza A + B
what is oseltamivir indicated for?
treatment of uncomplicated illness and prevention of flu
what form does oseltamivir come in?
suspension and oral tablet
when should oseltamivir be taken?
start within 2 days of exposure
T/F: oseltamivir may ↓ therapeutic effects of flu vaccine
TRUE; avoid 2 days prior to vaccine or if you’ve had the vaccine and experience flue symptoms → wait 2 weeks
what form does zanamivir come in?
powder form inhaler
what is zanamivir indicated for?
treatment and prophylactic flu related s/sx
what are the AEs of oseltamivir and zanamivir?
none common; behavioral possible → agitation, delirium, confusion
what teaching should be done with zanamivir and oseltamivir?
start within 2 days of exposure
what is the outcome of zanamivir and oseltamivir?
↓ duration or prevention of flu-related sxs
what is candida?
a fungus that usually lives on skin and mucous membranes
what occurs when there is an overgrowth of candida?
superficial and systemic infections
what types of candida infections are there?
thrush, yeast infections, athlete’s foot
what are the types of possible systemic infection?
histoplasmosis, aspergillosis, coccidiomycosis (↑ risk of fungal infections in ↓ immunecompromised)
__________ candida infections form in immmunocompromised patient and the immunosuppressed
opportunistic
T/F candida is difficult to treat and has an extensive treatment
TRUE; treatment can last weeks to months
what is nystatin indicated for ?
tx of skin, vaginal, and oropharyngeal candidiasis - fungal infections
how does nystatin work?
disrupts fungal cell wall membrane → allows intracellular contents to leak out
what forms is nystatin available in?
available in lozenge, suspension, tablets, ointment, and powder
what is important to teach with nystatin lozenges?
must be dissolved orally; cannot chew
what is important to teach with nystatin suspension?
must use swish-and-swallow; if taking multiple meds→ oral first then nystatin; shouldn’t eat or drink for 20 min; if sleeping or can’t follow direction → paint their mouth
what 2 teaching points are important with a general fungal infection?
- keep affected areas clean and dry (use something to wick away moisture - pillow case0
- wear light/cool clothing
what are the adverse effects of nystatin?
cramps with oral forms; skin irritations with topicals
how are systemic fungal infections caused?
inhaled spores affect respiratory system
what are the 3 main systemic fungal infections?
histoplasmosis, aspergillosis, and cocciodiomycosis
what are 3 characteristics of histoplasmosis?
- most common in US
- found in bird and bat droppings
- transmitted during cleanup or demolition of projects
what are 2 characteristics of aspergillosis?
- acquired from nosocomial or environment sources (mold spores thrive in air vents)
- likely to infect weakened immune systems
what are 3 characteristics of cocciodiomycosis?
- aka “valley fever” caused by coccidioides
- lives in soil; mostly found in mexico/central america
- infection in the lungs, can become disseminated → can be deadly
what are the sxs of all three systemic fungal infections?
dry cough, wheezing, SOB, fever, chest pain, fatigue, chills, body aches → 1 - 3 weeks after exposure to spores
what are the indications for fluconazole?
oropharyngeal or esophageal candidiasis; serious systemic infections
what is the action of fluconazole?
inhibits synthesis of fungal sterols → disrupts cell wall membrane → contents leak out
what is important to assess with fluconazole?
ASSESS KIDNEY FUNCTION (>80% excreted unchanged by kidneys, < 10% metabolized by liver)
- monitor BUN, creatinine, and liver function tests (ALK)
what forms does fluconazole come in?
PO and IV
what are the AEs of fluconazole?
GI distress (diarrhea/cramping) , SJ syndrome with immunosuppression
what are the drug to drug interactions of fluconazole?
may ↑ risk of bleeding with warfarin and ↑ hypoglycemic effects of glipizide and glyburide (↓ BGs)
what are the indications of amphotericin B?
progressive, systemic fungal infections
T/F amphotericin B is fungistatic or fungicidal
TRUE
T/F amphotericin B can cause acute infusion reactions and nephrotoxicity
TRUE
`what are the AEs of amphotericin B?
nephrotoxicity, chest pain, hypotension, ↑ liver enzymes, hypokalemia, chills, fever, phlebitis
what are the 7 NIs of amphotericin B?
- assess VS q1h and anaphylaxis
- ensure adequate hydration
- may pre-medicate w/ antipyretics, antihistamines, corticosteroids, analgesics, and anti-emetics
- monitor infusion closely during and after admin
- infuse slowly over 2 - 6 hrs
- own pump line
- elimination slow (can be detected 7 wks after D/C)
what of medication is metronidazole?
bactericidal, trichomonacidal (parasites that cause STIs), and amebicidal (amebes) - broad spectrum coverage (doesn’t cover fungal)
how does metronidazole work?
disrupts DNA and protein synthesis
whatare the indications of metronidazole?
intra-abdominal, skin-to-skin structures, lower-respiratory tract, bone/joint, and septicemia
what is the spectrum coverage for PO metronidazole?
c. diff (IV form also effective) - mild/mod (PO) → vancomycin first line for c diff.
dysentery, trichomoniasis,
h. pylori (can cause peptic ulcers)
what are the AEs of metronidazole?
abd. pain, anorexia, dizziness, dry mouth, metallic taste
drug-drug interactions for metronidazole?
↑ effects of warfarin
