Fungal and Viral Infections Flashcards
General Info on mycobacteria
causes typical/atypical illnesses, acute and chronic
LIFECYCLE
- slow growth, special cell wall with infections protected in tubercles (reason why one of them is called tuberculosis)
Typical mycobacteria infections: Mycobacterium tuberculosis (TB) and Mycobacterium leprae (leprosy)
Atypical: M. scrofulaceum (Scrofula); M. kansaii and M. marinum (skin infections); M. avium-intracellulare in immuno-compromised hosts (AIDS COPD)
what is it when a child is infected with TB?
TB in community, is a sentinel event
how is TB transmitted
airborne (lab culture takes weeks so acid-fast stains of sputum and skin testing and image CXR)
What are the two types of TB?
- Latent: positive skin test, not progressed to illness and is treated due to “sero-conversion”
- Active: esp in immuno, a child, HIV
a) pulmonary: coughing, night sweats, weight loss, hemoptysis
b_ miliary: other parts of body
what are the bactericidal drugs to treat TB?
- isoniazid (INH): AEs include peripheral neuropathy (prevent with vitamin B6 pyridoxine 5–100 mg/day); hepatotoxic -> monitor LFTs
- rifamycins (Rifampin, RIF and Rifapentin, Priftin): adjunct, AEs include urine/sweat, turning read, hepatotoxic, flu-like symptoms of myalgia headahce n/v
- drug interaction with CYP P450 enzymes may increase clearance clearance of oral contraceptives making them less effective
- rifabutin (Mycobutin): oral drug, synthetic agent better against M.avium
- pyrazinamide (PZA): adjunct when resistance issue; AEs of hepatotoxic, hyperuricemia, and gouty arthritis
- streptomycin: doesn’t penetrate CSF (can’t treat CNS TB) IM drug
- nephrotoxic, ototoxic (vestibular toxic)
- capreomycin: similar to streptomycin; IM drug
bacteriostatic drugs to treat TB
- static=slow down so typically used in combo
1. para-aminosalicylic acid (PAS, aminosalicylic acid) oral drug; Aes of mono-like syndrome, GI intolerance
2. ethambutol (Myambutol): oral drug, AEs retrobulbar neuritis, loss of central vision; must have baseline opthalmic exam to establish baseline before starting drug
Other drugs with anti-TB effects
- aminoglycosides: kanamycin, amikacin (renal/ototoxic)
2. fluro-quinolones: levofloxacin, moxifloxacin
What’s the treatment protocols for latent TB infections (LTBIs)?
INH x 9 months or RIF x 4 months
What’s the treatment protocol for resistant infections?
- daily treatment no lapses or resistance
- DOT: direct observation of treatment for 1st week
- combo therapy
- at least one bactericidal
- sensitivity testing checks for MDRTB or multi-drug resistant TB
if someone has TB, what’s important information for them?
referall to health department; provide lab monitoring, xrays, usually free drugs, this is nurse managed
Older and newer drugs for leprosy
older: many aes, renal, gi, rashes
1. injectable dapsone (IM acedapsone)
2. oral dapsone
3. clofazimine (Lamprene)
newer
1. thalidomide (Thalomid)
- originally anxiolytic, can cause birth defects
AEs: teratogencity, periph neurop, rash, hypothyroid, neutropenia, fever, increased HIV-RNA levels
mycobacterium avium overview
- in immuno not healthy; sometimes called opportunistic infection
- multi-drug: fluroquinolones, macrolide, and usual mycobacterium drugs
antifungal drugs
also called anti-mycotic
1. Azoles (imidazoles and triazoles)
- poss heart failure/liver
- lots of drug-drugs
SYSTEMIC: fluconazole (Diflucan), ketoconazole (Nizoral), itraconazole (Sporanox), voriconazole (Vfend), posaconazole (Noxafil)
TOPICAL: clotrimazole (Lotrimin, Mycelex), miconazole (Micatin), ketoconazole (Nizoral shampoo), econazole (Spectazole), oxiconizole (Oxistat), sulconizole (Exelderm solution)
- polyenes: amphotericin B (Fungizone, also a macrolide antibiotic); Nystatin (Mycostatin, Nystatin, Nilstat)
- allylamines: neutropenia, liver, SJS, less drug-drugs
- naftate (Naftin cream), terbinafine (Lamisil, cream/oral/spray) - potassium iodide: older drug, no longer used
- flucytosine (Ancoben): severe mycoses/fungal infections
- griseovulvin (Gris-Peg, Fulvicin)
- older, longterm to work
- take with fatty food
- teratogenic
Non-pharmacologic measure in fungal infections
- education to prevent recurrence
- fungi keep ventilated/dry
- avoid trauma/lifestyle factors
- use clean, dry white
- manage underlying conditions (ex DM hyperglycemia) - surgical removal of the nail in onychomycosis
- nail hygiene (for onychomycosis):
- nails clean and short
- clip tonails straight, file
- avoid high heels, narrow-toed shoes
- - avoid community nail stuff
- acoid barefoot/clean dry
- discard old shoes, sprary with antifungal sprary periodically
which gloves are use for dry manual work and which for wet?
- cotton - dry
2. vinyl - wet
what are topical anti-fungals used for?
- yeast infections (Candidiasis, tinea versicolor) and ringworm
what are the topical imidazoles
- clotrimazole (Lotrimin, Mycelex), miconazole (Micatin), ketoconazole (Nizoral), econazole (Spectazole), oxiconizole (Oxistat), sulconizole (Exelderm), sertaconazole (Ertaczo)
- combo therapy: corticosteroi + antifungal (ex Lotrisone, + clotrimazole) for fungal and inflammaiton
- OTCs: miconazole 2% (Lotrimin AF), clotrimazole 1% (Lotrimin AF cream) Butenafine 1% (Lotrimin Ultra)
- RX: terbinafine (Lamisil AT)
what are the topical anti-fungals for fungal/mucosal skin infections
- topic imidazoles
- topical allylamines: naftifine (Naftin, terbinfaine (Lamisil, spray)
- topical polyenes: nystatin (Mycostatin, Nystatin), amphotericin B (Fungizone)
- topical hydroxypiridone: ciclopirox (Loprox cream and Penlac nail lacquer)
- topical naphthiomate: tolnaftate (Tinactin)
what is pityriasis
tinea versicolor; involves lare SA and treated with terfinadine spray (Lamisil spray of 1% solution)
what is seborrhic dermatitis
on scalp
- often fungal infection
1. Nizoral (ketoconazole) shampoo to treat underlying Pitysporum
2. Xologel 2% (ketoconazole) get once daily
what represents 50% of all nail disorders
onychomycosis (Nail fungus)
treatments for onychomycosis
- Topical: must do filing/clipping so will penetrate nail; Penlac Nail Lacquer (8% cicloprox olamine) daily
- long-term systemic: potentially toxic, older drugs (griseofulvin, Gris-Pet; ketoconazole, Nizoral)
- short-term systemic (commonly used): off-lael fluconazole (Diflucan); label itraconazole (Sporanox); terbinafine (Lamisil)
- time length of drugs varies and if treating toe or fingernail
- Aes: heart failure, liver, rash
what do 2/3 of infants gets
diaper dermatitis (rash); though diapers with increased absorbency have reduced incidences; breast-fed infants have less diaper rash
non-pharm treatment for diaper dermatitis
- keep dry/reduce contact time of urine.feces (frequent changes)
- clean are with water or baby wipes w/out perfume
- avoid corn or talcum powders (can be inhaled)
- use dye-free diapers and go “diaper free” if possible to dry skin
pharm treatment of diaper dermatitis
- skin protectants: barrier for skin/lubricate against friction
- A&D ointment, lanolin, zinc oxide, petrolatum
- antifungal meds: antifungals with nystatin, clotrimazole, miconazole due to Candida infections
- for diaper rash: Vusion combo of zinc oxide, petrolatum, and .25% miconazole (much less than Monistat 4% or OTC Desenex/Micatin reason is to reduce systemic absorption into infant)
- note: could by zinc oxide, petrolatum aka Vaseline and mix into Monistat/Desenex and would cost much less
- for diaper rash: Vusion combo of zinc oxide, petrolatum, and .25% miconazole (much less than Monistat 4% or OTC Desenex/Micatin reason is to reduce systemic absorption into infant)
- Topical steroids: only for severe cases, use hydrocortisone cream (HC 1%) for up to 2 weeks; check baby in one week otherwise maybe other
when do serious systemic mycotic infections occur?
- immuno comp
- HIV/AIDS, cancer, organ transplant, high-dose steroids
- infections under specialist care, most drugs with serious AEs - amphotericin B (Fungizone), amphotericin B lipid complex (Abelcet) – may be nephrotoxic
- nystatin: PO use for GI Candida and oral thrush
- flucytosine (Ancoben) may cause leucopenia, nausea, hepatitis, bone marrow depression
- azoles: ketoconazole (Nizoral), fluconazole (Diflucan), itraconazole (Sporanox), voriconazole (Vfend), posaconazole (Noxafil)
- echinocandins: caspofungin (Cancidas IV), anidulafungin (Eraxis IV), micafungin (Mycamine), anidulafungin (Eraxis)
management of PCP
PCP = Pneumocystis carinii Pneumonia
- in immuno comp, may need prophylaxis drugs
DOC: TMP/SMZ (trimethoprim/sulfamethoxazole, Bactrim, Septra)
Other drugs: aerosolized pentamidine (NebuPent), sulfone drugs dapsone (AED) alone or with antiparasitic pyrimethamine (Daraprime, adds dapsone); antiparasitic atovaquone (Mepron, anti-malarial), anti-folate drug trimetrexate (Neutrexin), other combos like clindamycin (Cleocin) + primaquine
Adjunct drugL prednisone (glucocorticoid steroid) if patient is hypoxic
what causes malaria?
protozoans Plasmodium falciparum; P. vivax and P. ovale
- mosquito vector in tropical/subtropica; may be fetal; is resistance to ant-malarials; prophylaxis for travellers
what are some non-pharm ways to prevent malaria
- mosquito repellant, sleep in screen areas, don’t go out after sunset
repellants. …
1. DEET: higher%, longer but not better (not for infants under 2 months, don’t use on face, not on hands)
2. picaridin in OTC Cutter
3. permethrin (Duranon, Permanone): liquid/spray for clothes nets bags etc
Prevention drugs of malaria
- chloroquine (Aralen): DOC if chloroquine-sensitive malaria area
- multiple toxicities -> CNS, retinal damage, hemolysis in G6PD deficiency
- malarone for chloroquine-resistant: combo atovaquone + proguanil daily; GI AEs, SJS
- mefloquine (Lariam): no if depression, anxiety, psychosis, schizo, suicidality, seizure, cardiac (long QT)
- doxycycline: for 8+ and not pregnant
Treatment of malaria
- chloroquine (Aralen)
- for chlorquine resistant use quinine plus Fansidar (pyrimethamine+sulfadoxine), quinine (Qualaquine), mefloquine (Lariam), halofantrine (Halfan), primaquine, atocaquone+proguanil (Malarone), doxycycline
The worm infections
- called helminthic infestations-
PINWORM
- caused by Enterobius vermicularis, called enterobiasis
- most common worm in USA
- diagnosis made at night with tape
- may cause vulvovaginitis
- treat whole family, repeat dose in two weeks (drugs paralyze worms and then pass stoll)
- rx= mebendazole (Vermox), albendazole (Zentel)
- *****REMEMBER repeat dose in 2 weeks
- OTC= pyrantel (Pin-X) liquid
ROUNDWORM
- caused by Ascaris, thus called ascariasis
- abdominal discomfort/pain and anemia (children)
- drugs= mebendazole (Vermox), pyrantel (Pin-X OTC), albendazole (Zentel), nitazoxanide (Alinia)
Scabies
- PRURITIC skin infestations
DRUGS
Topical: 5% permethrin (Elimite) cream, 10% crotamiton (Eurax), second-line lindane 1% (G-well), malathion .5% (Ovide), permethrin 1% (Nix), and OTC (piperonyl butoxide 4% or pyethrum .33%)
Systemic: oral drug ivermectin (Mectizan)
chiggers
red bug/harvest mite
- VERY PRURITIC
treatment: antipruritic
prevention: avoidance of areas with chiggers, use DEET repellant, let infestation run its course
Protozoans
- trichomoniasis
- cyclospora: found on unwashed fruit, diarrhea, treat with TMP/SMX
- cryptosporidiosis+giardiasis: from water protozoans, diarrhea,
- - nitazoxanide (Alinia) for diarrhea; metronidazole (Flagyl) for Giardia/more complicated infections; tinidazole (Tindamax)
What are the head lice
Pediculus capitis (head louse, P. corporis (body louse, Phthirus pubis (pubic louse or crabs)
non-pharmacologic managemnt of lice
***MUST be combined with drug therapy
- wet combing: fine touth comb on shampooed hair
- petroleum jelly/olive oil: cover hair then use shower cap to suffocate mites or for eyelashes
what adjunctive therapies are used for lice
- anti-itch (antihistamines, topical corticosteroids)
2. for sumperimposed bacterial infection from scratching etc
primary drug therapy for lice
- TOPICAL
- DOC = OTC 1% permethrin (Nix) or prescription 5% permethrin (Elimite)
- others: OTC pyrethrins with peperonyl butoxide (Rid, Clear, Pronto) which are natural extracts from chrysanthemum flowers (needs repeating in one weeks, often fails); malathion (Ovid topical which if flammable so CAN’T use hair dryer); lindane (Kwell 1% shampoo, lotion) - SYSTEMIC (for resistant lice)
- oral ivermectin (Mectizan or Stromectol)
important infor for anti-viral agents and viral infections
- viruses must live in host cell/take over to replicate
- viruses = nucleic acid (DNA/RNA) covered by protein
- anti-virals try to interrupt specific step in viral life cycle
- MANY/MOST ANTI-VIRALS HAVE TOXIC POTENTIAL
life cycles of viruses
- adsorption (NOT absorption) via fusion to host cell (attaches at receptor sites such as CD4 receptors on T-lymphocytes)
- penetration of host cell - viral protein coat dissolves and exposes viral DNA/RNA
- synthesis of enzymes that replicate viral nucleic acid -> synthesis of viral proteins -> assembly of mature viral particles (virions
- death of cell and release of viral particles
some important information on how viruses infect
- retroviruses like HIV have RNS that has t be copied to DNA to take over cell
- many viruses co-infect (if you have HIV, more likely to get hepatitis)
- some viruses like HIV cause other effects like loss of immune system through CD4 T cell destruction
viral prevention/treatment
- Vaccine
- Chemoprophylaxis: symptoms often appear only when viral load (viremia) in bloodstream is very large; prophylaxis with anti-viral may prevent symptoms
- admin of antiviral after symptoms appear
- PEP
- - for HIV or HBV; special chemoprophylaxis; occupational PEP and non-occupational or nPEP
some types of antivirals
- Gamma globulins: block viral penetration into cell; immunoglobulins our body makes in response to viruses
- - “pooled” from people’s blood for wide variety
- - hyperimmune concentrated from plasma with high antibody levels against specific viruses
EXAMPLES
a) HBIG (hepatitis-B immune globuline) for hepatitis B
b) VIGIV (vaccinia immune globulin intravenous) for smallpox
c) VZIG (varicella zoster immune globulin) - given with 4 days of chickenpox exposure
d) IVIG (intravenous immune globulin) and SCIG (subcutaneous immune globulin) for primary immune deficiency
- – effects can be less if other vaccines given w/in 6 months
- Interferons: made in body to interfere with viral protein synthesis; also useful in cancer/MS
a) Anti-viral Inerferons
- antivirals: interferon alfa-2a (Roferon-A), interferon alfa-2b (Intron-A), PEG-Intron, interfero nalfa-n3 (Alferon N), interferon alfa-n1 (Wellferon), Betaseron, peginterferon alfa-2a (Pegasys)
- for hep B/C: PEG-Intron (pegylated Intron-A, ribavirin + interferon alfa-2a, Pegasys (peginterferon alfa-2a)
- pegylate formulations: links polyethylene glycol to make it stay longer in bloodstream (word peg at beginning of drug name)
other uses for interferons: MS - interferon beta-1b (Betaseron), iterferon beta-1a (Avonex)
AEs: like bad flue (myalgia, fever, headache, n/v); suicidal/depression, endocrine complications
- Zinc - for rhinovirus (upper resp infection, URI)
- may be safe if used for first few days of URI symptoms but can’t be sure of safety
- at effective doses, significant side effects (still birth, neutropenia copper deficiency, anemia, lymphopenia) esp if used long-term
HPV
human papilloma virus
- causes anal cancer, cervical cancer, anogenital warts
1) Vaccines for prevention: Gardasil and new Cervarix
2) Drugs: off label -injections of interferons or cidofovir cream (Vistide)
on label: imiquimod (Aldara) topical, podofilox (Condylox) topical, topical tricloroacetic acid (TCA), topical pdophyllin, topical cryotherapy (liquid nitrogen or cryoprobe)
Herpes viruses
includes: colds sores (Herpes labialis), chingles and chickenpox (Varicella zoster virus, VZV), genital herpes (Herpes simplex virus, HSV type 2)
- shingles (Varicella Zoster Virus, VZV)
- painful rash on one side of body
- antivirals: acyclovir (Zovirax), valacyclovir (Valtrex), famcyclovir (Famvir)
- adjuncts for pain
- after infection, PHN or long-term neuralgia pain may develop, treated with chronic drugs like ADs, AEDs, corticosteroids
- Zostavax: vaccine for prevention of shingles/PHN - Genital herpes (HSV type 2)
- for initial episodic treatment: acyclovir (Zovirax), valacyclovir (Valtrex), famciclovir (Famvir); chronic higher doses - herpes labialis (HSV type 1) cold sore
- rx: penciclovir cream 1% (Denavir), acyclovir cream 5% (Zovirax cream)
- OTC: sinecatechins (Veregen) from green tea, docusanol 10% cream (Abreva)
- OTC CAM: honey
- acyclovir, famciclovir, valacyclovir
- in serious neonatal invections: IV acyclovir
RSV in children
respiratory syncytial virus
- prevention: premies
- respigam: older drug, monthly IV hyperimmune globulin
- palivizumab (Synagis): newer, IM qmonthly - treatment: ribavirin as aerosol (Virazole) can be toxic; oral ribasphere (for hep C)
CMV treatment
cytomegalovirus
- somtimes seen in immunocompromised
- ganciclovir (Cytovene) and newer foscarnet (Foscavir, parenteral), valganciclovir (Valcyte, oral), cidofovir (Vistide, IV for CMV retinitis in AIDS patients
influenza treatment
- can be influenza A or B
- can change from year to year (swine flue was H1N1)
PREVENTION: vaccination, new each year
TREATMENT
- neuraminidase inhibitors for influenza A/B: zanamivir (Relenza), oral oseltamivir (Tamiflu) -> AE of inhaled is lungs, AE of oral is neuropsychiatric symptoms like seizures
- adamantamines for influenza A: amantidine (Symmetrel), rimantidine (Flumadine) -> prob with resistance
what can you use to treat bird flu
neuraminidase ihibitors
Hepatitis B
HBV
- main concern: don’t progress to chronic (liver cancer/death)
- usually needlestick or con-infection, transfusion contamination
TREATMENT: injectable interferons like interferon alfa-2a (intron-A) and Pegasys and oral antivirals like lamivudine (Epivir-HBV), adefovir dipivoxil (Hepsera), entecavir (Baraclude), telbivudine (Tyzeka) - highrate of relapse
Hepatitis C
HCV
- chronic form, liver failure
- treatment for chronic HCV: SC peginterferon alfa-2b (Peg-Inton) plus ribavirin oral, SC peginterferon alfa-2a (Pegasys) plus ribavirin oral
- treatment for acute HCV: interferon alfa-2b (Intron-A)
what are the type of drugs used to treat HIV?
call antiretrovirals
- NNRTIs (non-nucleoside reverse transcriptase inhibitors)
- NRTs or NtRTIs (nucleoside/nucleotide analogs)
- protease inhibitors (PI)
- fusion inhibitors (enfuvirtide, Fuzeon injectable)
- CCR5 co-receptor antagonists (maraviroc, Selzentry)
- HIV-integrase strand enzyme inhibitor (ratelgravir, Isentress)
what are the drug-drugs of antiretrovirals?
methadone, TB antibiotics, macrolide antibiotics, cholesterol drugs, BP meds (almost every class of drugs)
Therapy protocols for HIB
ARV = antiretroviral therapy HAART = highly active antiretroviral therapy
- clinical guidlines like viral load or CD4 count or con-infections dictate choice of drug
- must NOT have lapse in therapy
what are the NNRTIs for HIV therapy
- block viral enzyme
- nevirapine (Viramune), delavirdine (Rescriptor), efavirenz (Sustiva)
AEs: teratogenic, drug-drugs
NRTs/NtRTIs for HIV therapy
- used to raise CD4 counts and also for needlestick prophylaxis
- adefovir dipivoxil (Hepsera), ribavirin (Virazole, Rebetol) acyclovir (Zovirax) valacyclovir (Valtrex), famciclovir (Famvir), pencyclovir (Denavir) topical, ganciclovir (Cytovee) etc etc
some are used more for HIV: zidovudine (ZDV, AZT, Retrovir), lamivudine (Epivir), zalcitabine (Hivid), stavudine (Zerit), adefovir (Hepsera, Preveon), abacavir (Ziagen), emtricitabine (Emtriva), tenofovir (Viread)
- look up fixed combos
AEs: anemia, hepatitis, myopathy, kidney damage, metabolic problems acidosis, genetic hypersensitivities
DRUG-DRUG= acetaminophen
protease inhibitors for HIV
interfere with an enzyme needed by HIB
- indinavir (Crixivan), saquinavir (Invirase), etc
AEs: hyperglycemia (DM2 development), dyslipidemia, liver toxicity, retinitis from CMV infection, bleeding, osteoporosis
CAM interaction = St. John’s wort cna inactivate PI drugs
