Micro, USMLE Part 2 Flashcards
1
Q
Levels as HIV infxn progresses: CD4+ lymphocytes? Anti-p24 Abs? Anti-gp120 Abs? Virus, p24 Ag?
A
CD4+ T-cells have an early dip, stabilize, and fall during stages 3-4 (years after infxn) Anti-p24 and Anti-gp120 Abs rise starting ~1 mo. post-infxn, stabilize @ 3 mos (at end of acute infxn). Virus, p24 Ag: spike early (w/ start of acute Sx’s), drop to low level until stages 3-4 (years later), when they take off
2
Q
Organ system affected in AIDS: Brain (what is the infxn/dz associated?)
A
Infxn/dz associated w/ AIDS: Crytococcal meningitis Toxoplasmosis CMV encephalopathy AIDS dementia PML (JC virus)
3
Q
Organ system affected in AIDS: Eyes (what is the infxn/dz associated?)
A
Infxn/dz associated w/ AIDS: CMV retinitis
4
Q
Organ system affected in AIDS: Mouth and throat (what is the infxn/dz associated?)
A
Infxn/dz associated w/ AIDS: Thrush (Candida albicans) HSV CMV Oral hairy leukoplakia (EBV)
5
Q
Organ system affected in AIDS: Lungs (what is the infxn/dz associated?)
A
Infxn/dz associated w/ AIDS: Pneumocystis jiroveci pneumonia (PJP) TB histoplasmosis
6
Q
Organ system affected in AIDS: GI (what is the infxn/dz associated?)
A
Infxn/dz associated w/ AIDS: Cryptosporidiosis Mycobacterium avium-intracellulare complex CMV colitis Non-Hodgkin’s lymphoma (EBV) Isopora belli
7
Q
Organ system affected in AIDS: Skin (what is the infxn/dz associated?)
A
Infxn/dz associated w/ AIDS: Shingles (VZV) Kaposi’s sarcoma (HHV-8)
8
Q
Organ system affected in AIDS: Genitals (what is the infxn/dz associated?)
A
Infxn/dz associated w/ AIDS: Genital herpes warts cervical cancer (HPV)
9
Q
HIV-assicated infxns that increase in risk at CD4+ count:
A
Infxn: Oral thrush Tinea pedis (athlete’s foot) Reactivation VZV Reactivation tuberculosis Other bacterial infxns (e.g., H. influenzae, S. pneumoniae, Salmonella)
10
Q
HIV-assicated infxns that increase in risk at CD4+ count:
A
Infxn: Reactivation HSV cryptosporidosis Isopora Disseminated coccidioidomycosis Pneumocystis pneumonia
11
Q
HIV-assicated infxns that increase in risk at CD4+ count:
A
Infxn: Candidal esophagitis Toxoplamosis histoplasmosis
12
Q
HIV-assicated infxns that increase in risk at CD4+ count:
A
Infxn: CMV retinitis and esophagitis Disseminated M. avium-intracellulare Cryptococcal meningitis
13
Q
Neoplasms associated w/ HIV
A
Kaposi’s sarcoma (HHV-8) Invasive cervical carcinoma (HPV) Primary CNS lymphoma non-Hodgkin’s lymphoma
14
Q
HIV encephalitis
A
Occurs late in the course of HIV infxn. Virus gains CNS access via infected Macrophages. Microglial nodules w/ multinucleated giant cells.
15
Q
Prions What are they? What dz’s do they cause? Normal vs. pathologic prions?
A
Infectious agents that do not contain RNA or DNA (consist only of proteins); encoded by cellular genes. Dz’s: Creutzfeldt-Jakob dz (CJD – rapidly progressive dementia), kuru, srapie (sheep), mad cow dz Associated w/ spongiform encephalopathy . Normal prions have alpha-helix conformation; pathologic prions (like CJD) are beta-pleated sheets. Pathologic conformation accumulates b/c it is resistant to proteinase digestion.
16
Q
Dominant normal flora of the: Skin
A
Staphylococcus epidermis
17
Q
Dominant normal flora of the: Nose
A
S. epidermis; colonized by S. aureus
18
Q
Dominant normal flora of the: Oropharynx
A
Viridans group streptococci
19
Q
Dominant normal flora of the: Dental plaque
A
Streptococcus mutans
20
Q
Dominant normal flora of the: Colon
A
Bacteroides fragilis > E. coli
21
Q
Dominant normal flora of the: Vagina
A
Lactobacillus, colonized by E. coli and GBS
22
Q
Neonates and normal flora
A
Neonates delivered by cesarean section havve no flora, but are rapidly colonized after birth.
23
Q
Food poisoning from: Vibrio parahemolyticus and V. vulnificus
A
Food: Contaminated seafood (V. vulnificus can also cause wound infxn from contact w/ contaminated water or shellfish)
24
Q
Food poisoning from: Bacillus cereus
A
Food: reheated rice. (Food poisoning from reheated rice? Be Serious! [B. cereus])
25
Food poisoning from: S. aureus
Food: Meats, mayonnaise, custard (pre-formed toxin)
26
Food poisoning from: Clostridium perfringens
Food: reheated meat dishes
27
Food poisoning from: Clostridium botulinum
Food: improperly canned foods (bulging cans)
28
Food poisoning from: E. coli O157:H7
Food: Undercooked meat
29
Food poisoning from: Salmonella
Food: poultry, meat, and eggs.
30
What are two bacteria that cause a food poisoning that starts quickly and ends quickly?
S. aureus and B. cereus
31
Bugs that cause diarrhea: Campylobacter Type of diarrhea? Findings?
Bloody diarrhea. Comma- or S-shaped organisms; growth at 42C; Oxidase (+) [bugs that cause diarrhea: type of diarrhea and findings]
32
Bloody diarrhea. Comma- or S-shaped organisms; growth at 42C; Oxidase (+) [bugs that cause diarrhea: type of diarrhea and findings]
Bugs that cause diarrhea: Campylobacter
33
Bugs that cause diarrhea: Salmonella Type of diarrhea? Findings?
bloody diarrhea. Lactose (-); Flagellar motility [bugs that cause diarrhea: type of diarrhea and findings]
34
bloody diarrhea. Lactose (-); Flagellar motility [bugs that cause diarrhea: type of diarrhea and findings]
Bugs that cause diarrhea: Salmonella
35
Bugs that cause diarrhea: Shigella Type of diarrhea? Findings?
Bloody diarrhea Lactose (-) Very low ID50 Produces Shiga toxin [bugs that cause diarrhea: type of diarrhea and findings]
36
Bloody diarrhea Lactose (-) Very low ID50 Produces Shiga toxin [bugs that cause diarrhea: type of diarrhea and findings]
Bugs that cause diarrhea: Shigella
37
Bugs that cause diarrhea: Enterohemorrhagic E. coli (EHEC) Type of diarrhea? Findings?
Bloody diarrhea O157:H7 Can cause HUS Makes Shiga-like toxin [bugs that cause diarrhea: type of diarrhea and findings]
38
Bloody diarrhea O157:H7 Can cause HUS Makes Shiga-like toxin [bugs that cause diarrhea: type of diarrhea and findings]
Bugs that cause diarrhea: Enterohemorrhagic E. coli (EHEC)
39
Bugs that cause diarrhea: Enteroinvasive E. coli (EIEC) Type of diarrhea? Findings?
Bloody diarrhea. Invades colonic mucosa. [bugs that cause diarrhea: type of diarrhea and findings]
40
Bloody diarrhea. Invades colonic mucosa. [bugs that cause diarrhea: type of diarrhea and findings]
Bugs that cause diarrhea: Enteroinvasive E. coli (EIEC)
41
Bugs that cause diarrhea: Yersinia enterocolitica Type of diarrhea? Findings?
Bloody diarrhea Day-care outbreaks Pseudoappendicitis [bugs that cause diarrhea: type of diarrhea and findings]
42
Bloody diarrhea Day-care outbreaks Pseudoappendicitis [bugs that cause diarrhea: type of diarrhea and findings]
Bugs that cause diarrhea: Yersinia enterocolitica
43
Bugs that cause diarrhea: C. difficile Type of diarrhea? Findings?
Can cause both watery and bloody diarrhea. Pseudomembranous colitis. [bugs that cause diarrhea: type of diarrhea and findings]
44
Can cause both watery and bloody diarrhea. Pseudomembranous colitis. [bugs that cause diarrhea: type of diarrhea and findings]
Bugs that cause diarrhea: C. difficile
45
Bugs that cause diarrhea: Entamoeba histolytica Type of diarrhea? Findings?
Bloody diarrhea. Protozoan. [bugs that cause diarrhea: type of diarrhea and findings]
46
Bloody diarrhea. Protozoan. [bugs that cause diarrhea: type of diarrhea and findings]
Bugs that cause diarrhea: Entamoeba histolytica
47
Bugs that cause diarrhea: Enterotoxigenic E. coli (ETEC) Type of diarrhea? Findings?
Watery diarrhea. Traveler's diarrhea Produces ST and LT toxins [bugs that cause diarrhea: type of diarrhea and findings]
48
Watery diarrhea. Traveler's diarrhea Produces ST and LT toxins [bugs that cause diarrhea: type of diarrhea and findings]
Bugs that cause diarrhea: Enterotoxigenic E. coli (ETEC)
49
Bugs that cause diarrhea: Vibrio cholerae Type of diarrhea? Findings?
Watery diarrhea. Comma-shaped organisms Rice-water diarrhea. [bugs that cause diarrhea: type of diarrhea and findings]
50
Watery diarrhea. Comma-shaped organisms Rice-water diarrhea. [bugs that cause diarrhea: type of diarrhea and findings]
Bugs that cause diarrhea: Vibrio cholerae
51
Bugs that cause diarrhea: C. perfringens Type of diarrhea? Findings?
Watery diarrhea. Also causes gas gangrene. [bugs that cause diarrhea: type of diarrhea and findings]
52
Watery diarrhea. Also causes gas gangrene. [bugs that cause diarrhea: type of diarrhea and findings]
Bugs that cause diarrhea: C. perfringens
53
Bugs that cause diarrhea: Protozoa Type of diarrhea? Findings?
Watery diarrhea Giardia, Cryptosporidium (in immunocompromised) [bugs that cause diarrhea: type of diarrhea and findings]
54
Watery diarrhea Giardia, Cryptosporidium (in immunocompromised) [bugs that cause diarrhea: type of diarrhea and findings]
Bugs that cause diarrhea: Protozoa
55
Bugs that cause diarrhea: Viruses Type of diarrhea? Findings?
Watery diarrhea. Rotavirus, adenovirus, Norwalk virus (norovirus). [bugs that cause diarrhea: type of diarrhea and findings]
56
Common causes of pneumonia in neonates (
Group B streptococci E. coli
57
Common causes of pneumonia in children (4wks - 18yrs)
Viruses (R SV) M ycoplasma C hlamydia pneumoniae S treptococcus pneumoniae (R unts M ay C ough S putum)
58
Common causes of pneumonia in adults (18-40yrs)
Mycoplasma Chlamydia pneumoniae Streptococcus pneumoniae
59
Common causes of pneumonia in Adults (40-65yrs)
Streptococcus pneumoniae H. influenzae Anaerobes Viruses Mycoplasma
60
Common causes of pneumonia in the elderly (>65)
Streptococcus pneumoniae Viruses Anaerobes H. influenzae Gram (-) rods
61
Common causes of nosocomial (hospital-acquired) pneumonia
Staphylococcus Enteric Gram (-) rods
62
Common causes of pneumonia in the immunocompromised
Staphylococcus Enteric Gram (-) rods Fungi Viruses Pneumocystis jiroveci (w/ HIV)
63
Common cause of pneumonia w/ aspiration
Anaerobes
64
Common cause of pneumonia in alcoholics/IV drug users
Streptococcus pneumoniae Klebsiella Staphylococcus
65
Common causes of pneumonia in CF
Pseudomonas
66
Common causes of post-viral pneumonia
Staphylococcus H. influenzae
67
Common causes of atypical pneumonia
Mycoplasma Legionella Chlamydia
68
Common causes of meningitis in newborn (0-6 months
Group B streptococci E. coli Listeria
69
Common causes of meningitis in children (6mos - 6yrs)
Streptococcus pneumoniae Neisseria meningitidis Haemophilus influenzae type B Enteroviruses
70
Common causes of meningitis (6-60yrs)
N. miningitidis Enteroviruses S. pneumoniae HSV
71
Common causes of meningitis in 60+ year-olds
Streptococcus pneumoniae Gram (-) rods Listeria
72
Viral causes of meningitis
Enteroviruses (esp. coxsackievirus) HSV HIV West Nile virus VZV
73
Common causes of meningitis in HIV
Cryptococcus CMV Toxoplasmosis (brain abscess) JC virus (PML)
74
Incidence of H. influenzae meningitis?
Has decreased greatly w/ introduction of H. influenzae vaccine in last 10-15 years.
75
CSF findings in meningitis: Bacterial [Pressure? Cell type? Protein? Sugars?]
Increased pressure Increased PMNs Increased protein Decreased sugar
76
Increased pressure Increased PMNs Increased protein Decreased sugar [CSF findings in meningitis -- what is the bug?]
Bacterial
77
CSF findings in meningitis: Fungal/TB [Pressure? Cell type? Protein? Sugars?]
Increased pressure Increased lymphocytes Increased proein Decreased sugar
78
Increased pressure Increased lymphocytes Increased proein Decreased sugar [CSF findings in meningitis -- what is the bug?]
Fungal/TB
79
CSF findings in meningitis: Viral [Pressure? Cell type? Protein? Sugars?]
Normal/increased pressure Increased lymphocytes Normal/increased protein Normal sugar
80
Normal/increased pressure Increased lymphocytes Normal/increased protein Normal sugar [CSF findings in meningitis -- what is the bug?]
Viral
81
Osteomyelitis in most ppl is due to...? Who gets most osteomyelitis?
Staph aureus in most ppl. Most osteomyelitis occurs in children.
82
Elevated CRP and ESR in osteomyelitis?
Classic findings, but nonspecific
83
Osteomyelitis in sexually active pt
Neisseria gonorrhoeae (rare) Septic arthritis more common
84
Osteomyelitis in diabetics and drug addicts
Pseudomonas aeruginosa
85
Osteomyelitis in Sickle cell
Salmonella
86
Osteomyelitis in prosthetic replacement
S. aureus and S. epidermis
87
Osteomyelitis in vertebra
Mycobacterium tuberculosis (Pott's dz)
88
Osteomyelitis with cat and dog bites/scratches
Pasteurella multocida
89
3 Most common causes of ambulatory UTI
1.) E. coli (50-80%) 2.) Staphylococcus saprophyticus (10-30%): 2nd most common cause of UTI in young, sexually active, ambulatory women 3.) Klebsiella (8-10%)
90
Common causes of UTI in a hospital setting
E. coli Proteus Klebsiella Serratia Pseudomonas
91
Gender and epidemiology of UTIs
10:1 women to men (b/c of short urethra colonized by fecal flora)
92
Predisposing factors to UTIs
Flow obstruction Kidney surgery Catheterization Gynecologic abnormalities Diabetes Pregnancy
93
Mechanisms of UTI infxn
Mostly caused by ascending infxns. In males: babies w/ congenital defects, elderly w/ enlarged prostates
94
Sx of UTI
Dysuria Frequency Urgency Suprapubic pain
95
Sx of Pyelonephritis
Fever Chills Flank pain CVA tenderness (costovertebral angle -- tender above kidneys on back)
96
UTI bugs: Serratia maracescens Features?
Some strains produce a red pigment; often nosocomial and drug-resistant.
97
Features: Some strains produce a red pigment; often nosocomial and drug-resistant. Which UTI bug is this?
Serratia maracescens
98
UTI bugs: Staphylococcus saprophyticus Features?
2nd leading cause of community-acquired UTI in sexually active women.
99
Features: 2nd leading cause of community-acquired UTI in sexually active women. Which UTI bug is this?
Staphylococcus saprophyticus
100
UTI bugs: Escherichia coli Features?
Leading cause of UTI. Colonies show metallic sheen on EMB agar.
101
Features: Leading cause of UTI. Colonies show metallic sheen on EMB agar. Which UTI bug is this?
Escherichia coli
102
UTI bugs: Enterobacter cloacae Features?
Often nosocomial and drug resistant.
103
Features: Often nosocomial and drug resistant. Which UTI bug is this?
Enterobacter cloacae
104
UTI bugs: Klebsiella pneumoniae Features?
Large mucoid capsule and viscous colonies
105
Features: Large mucoid capsule and viscous colonies Which UTI bug is this?
Klebsiella pneumoniae
106
UTI bugs: Proteus mirabilis Features?
Motility cuases swarming on agar. Produces urease; associated w/ struvite stones.
107
Features: Motility cuases swarming on agar. Produces urease; associated w/ struvite stones. Which UTI bug is this?
Proteus mirabilis
108
UTI bugs: Pseudomonas aeruginosa Features?
Blue-green pigment and fuity odor. Usually nosocomial and drug-resistant.
109
Features: Blue-green pigment and fuity odor. Usually nosocomial and drug-resistant. Which UTI bug is this?
Pseudomonas aeruginosa
110
List of UTI bugs
SSEEK PP S erratia marcescens S taphylococcus saprophyticus E scherichia coli E nterobacter cloacae K lebsiella pneumoniae P roteus mirabilis P seudomonas aeruginosa
111
Diagnostic markers of UTI
Leukocyte esterase: (+) = bacterial Nitrite test: (+) = Gram(-) organism
112
ToRCHeS infxns What are they? List?
These important infxns are transmitted in utero or during vaginal birth: T oxoplasma gondii o R ubella C MV H IV H SV-2 e S yphilis
113
Other important congenital infxns that do not fit into ToRCHeS
Listeria E. coli Group B streptococci All can be acquired placentally or from birth canal.
114
ToRCHeS infxns, organism: Toxoplasma gondii Major clinical manifestations?
Classic triad of chorionitis, intracranial calcifications, and hydrocephalus. May be asymptomatic at birth.
115
Major clinical manifestations: Classic triad of chorionitis, intracranial calcifications, and hydrocephalus. May be asymptomatic at birth. Which ToRCHeS organism is this?
Toxoplasma gondii
116
ToRCHeS infxns, organism: Rubella Major clinical manifestations?
Deafness Cataracts Heart defects (PDA, pulmonary artery stenosis) Microcephaly Mental retardation Blueberry muffin baby due to rash
117
Major clinical manifestations: Deafness Cataracts Heart defects (PDA, pulmonary artery stenosis) Microcephaly Mental retardation Blueberry muffin baby due to rash Which ToRCHeS organism is this?
Rubella
118
ToRCHeS infxns, organism: CMV Major clinical manifestations?
Petechial rash Intracranial calcifications Mental retardation Hepatosplenomegaly Microcephaly Jaundice 90% are asymptomatic at birth.
119
Major clinical manifestations: Petechial rash Intracranial calcifications Mental retardation Hepatosplenomegaly Microcephaly Jaundice 90% are asymptomatic at birth. Which ToRCHeS organism is this?
CMV
120
ToRCHeS infxns, organism: HIV Major clinical manifestations?
Hepatosplenomegaly Neurologic abnormalities Frequent infxns
121
Major clinical manifestations: Hepatosplenomegaly Neurologic abnormalities Frequent infxns Which ToRCHeS organism is this?
HIV
122
ToRCHeS infxns, organism: HSV-2 Major clinical manifestations?
Encephalitis Conjuntivitis Vesicular skin lesions Often asymptomatic at birth Most infxns are transmitted during birth thru an infected maternal genital tract.
123
Major clinical manifestations: Encephalitis Conjuntivitis Vesicular skin lesions Often asymptomatic at birth Most infxns are transmitted during birth thru an infected maternal genital tract. Which ToRCHeS organism is this?
HSV-2
124
ToRCHeS infxns, organism: Syphilis Major clinical manifestations?
Cutaneous lesions Hepatosplenomegaly Jaundice Saddle nose Saber shins Hutchinson teeth CN VIII deafness Rhinitis (snuffles)
125
Major clinical manifestations: Cutaneous lesions Hepatosplenomegaly Jaundice Saddle nose Saber shins Hutchinson teeth CN VIII deafness Rhinitis (snuffles) Which ToRCHeS organism is this?
Syphilis
126
Red rashes of childhood
Measles Rubella HHV-6 (roseola) Scarlet fever (group A streptococcus) Parvovirus B19 (slapped cheek rash)
127
STD's: Gonorrhea Organism? Clinical features?
Neisseria gonorrhoeae Urethritis, cervicitis, PID, prostatitis, epididymitis, arthritis, creamy purulent discharge
128
Neisseria gonorrhoeae Urethritis, cervicitis, PID, prostatitis, epididymitis, arthritis, creamy purulent discharge Disease?
Gonorrhea
129
STD's: Primary syphilis Organism? Clinical features?
Treponema pallidum Painless chancre
130
Treponema pallidum Painless chancre Disease?
Primary syphilis
131
STD's: Secondary syphilis Organism? Clinical features?
Treponema pallidum Fever, lymphadenopathy, skin rashes, condylomata lata
132
Treponema pallidum Fever, lymphadenopathy, skin rashes, condylomata lata Disease?
Secondary syphilis
133
STD's: Tertiary syphilis Organism? Clinical features?
Treponema pallidum Gummas (a non-cancerous growth, a form of granuloma) Tabes dorsalis General paresis Aortitis Argyll Robertson pupil
134
Treponema pallidum Gummas (a non-cancerous growth, a form of granuloma) Tabes dorsalis General paresis Aortitis Argyll Robertson pupil Disease?
Tertiary syphilis
135
STD's: Genital herpes Organism? Clinical features?
HSV-2 Painful penile, vulvar, or cervical ulcers; can cause systemic Sx such as: fever, HA, myalgia
136
HSV-2 Painful penile, vulvar, or cervical ulcers; can cause systemic Sx such as: fever, HA, myalgia Disease?
Genital herpes
137
STD's: Chlamydia Organism? Clinical features?
Chlamydia trachomatis (D-K) Urethritis, cervicitis, conjunctivitis, Reiter's syndrome, PID
138
Chlamydia trachomatis (D-K) Urethritis, cervicitis, conjunctivitis, Reiter's syndrome, PID Disease?
Chlamydia
139
STD's: Lymphogranuloma venereum Organism? Clinical features?
Chlamydia trachomatis (L1-L3) Ulcers, lymphadenopathy, rectal strictures.
140
Chlamydia trachomatis (L1-L3) Ulcers, lymphadenopathy, rectal strictures. Disease?
Lymphogranuloma venereum
141
STD's: Trichomoniasis Organism? Clinical features?
Trichomonas vaginalis Vaginitis Strawberry-colored mucosa
142
Trichomonas vaginalis Vaginitis Strawberry-colored mucosa Disease?
Trichomoniasis
143
STD's: AIDS Organism? Clinical features?
HIV Opportunistic infxns, Kaposi's sarcoma, lymphoma
144
HIV Opportunistic infxns, Kaposi's sarcoma, lymphoma Disease?
AIDS
145
STD's: Condylomata accumulata Organism? Clinical features?
HPV 6 and 11 Genital warts, koilocytes
146
HPV 6 and 11 Genital warts, koilocytes Disease?
Condylomata accumulata
147
STD's: Hepatitis B Organism? Clinical features?
HBV Jaundice
148
HBV Jaundice Disease?
Hepatitis B
149
STD's: Chancroid Organism? Clinical features?
Haemophilus ducreyi (it's so painful, you do cry ) Painful genital ulcer, inguinal adenopathy.
150
Haemophilus ducreyi (it's so painful, you do cry ) Painful genital ulcer, inguinal adenopathy. Disease?
Chancroid
151
STD's: Bacterial vaginosis Organism? Clinical features?
Garnderella vaginalis Noninflammatory, malodorous discharge (fishy smell) Positive whiff test Clue cells
152
Garnderella vaginalis Noninflammatory, malodorous discharge (fishy smell) Positive whiff test Clue cells Disease?
Bacterial vaginosis
153
Top bugs that cause Pelvic inflammatory dz
Chlamydia trachomatis (subacute, often undiagnosed) Neisseria gonorrhoeae (acute, high fever) Chlamydia trachomatis (the most common STD in the USA: 3-4milliion cases/year)
154
Signs and Sx's of Pelvic inflammatory dz
Cervical motion tenderness (chandelier sign) Purulent cervical discharge. May include: Salpingitis, endometritis, hydrosalpinx, and tubo-ovarian abscess.
155
Pelvic inflammatory dz can lead to... ?
Fitz-Hugh-Curtis Syndrome: infxn of the liver capsule and violin string adhesions of parietal peritoneum to liver.
156
What is salpingitis a risk factor for?
Ectopic pregnancy Infertility Chronic pelvic pain Adhesions
157
Other STD's that cause PID
Garnderella (clue cells) Trichomonas (corkscrew motility on wet prep)
158
Nosocomial pathogen: CMV, RSV Risk factor?
Newborn nursery
159
Risk factor for a nosocomial pathogen: Newborn nursery
What is the pathogen? CMV, RSV
160
Nosocomial pathogen: E. coli, Proteus mirabilis Risk factor?
Urinary catheterization
161
Risk factor for a nosocomial pathogen: Urinary catheterization What is the pathogen?
E. coli, Proteus mirabilis
162
Nosocomial pathogen: Pseudomonas aeurginosa Risk factor?
Respiratory therapy equipment
163
Risk factor for a nosocomial pathogen: Respiratory therapy equipment What is the pathogen?
Pseudomonas aeurginosa
164
Nosocomial pathogen: HBV Risk factor?
Work in renal dialysis unit
165
Risk factor for a nosocomial pathogen: Work in renal dialysis unit What is the pathogen?
HBV
166
Nosocomial pathogen: Candida albicans Risk factor?
Hyperalimentation
167
Risk factor for a nosocomial pathogen: Hyperalimentation What is the pathogen?
Candida albicans
168
Nosocomial pathogen: Legionella Risk factor?
Water aerosols
169
Risk factor for a nosocomial pathogen: Water aerosols What is the pathogen?
Legionella
170
The 2 most common causes of nosocomial infxns?
E. coli (UTI) S. aureus (wound infxn)
171
Presume Pseudomonas aeruginosa as the cause of a nosocomial infxn when...?
Presume Pseudomonas AIR uginosa when AIR or burns are involved.
172
When do you suspect Legionella as a cause of nosocomial infxn?
Suspect Legionella when a water source is involved.
173
Bug hints (if all else fails):Pus, empyema (collection of pus in pre-existing anatomical cavity), abscess What is the bug?
S. aureus
174
Bug hints (if all else fails):Pediatric infxn What is the bug?
haemophilus influenzae (including epiglottitis)
175
Bug hints (if all else fails):Pneumonia in CF, burn infxn What is the bug?
Pseudomonas aeruginosa
176
Bug hints (if all else fails):Branching rods in oral infxn What is the bug?
Actinomyces israellii
177
Bug hints (if all else fails):Traumatic open wound What is the bug?
Clostridium perfringens
178
Bug hints (if all else fails):Surgical wound What is the bug?
S. aureus
179
Bug hints (if all else fails):Dog or cat bite What is the bug?
Pasteurella multocida
180
Bug hints (if all else fails):Currant jelly sputum What is the bug?
Klebsiella
181
Bug hints (if all else fails):Sepsis/meningitis in newborn What is the bug?
group B strep
182
Antimicrobials by mechanism of action: Block cell wall synthesis by inhibition of peptidoglycan cross-linking
Drugs? Penicillin, ampicillin, ticarcillin, piperacillin, imipenem, aztreonam, cephalosporins [#1 below]
183
Antimicrobials by mechanism of action: Block peptidoglycan synthesis Drugs?
Bacitracin, Vancomycin [#2 below]
184
Antimicrobials by mechanism of action: Disrupt bacterial cell wall membranes Drugs?
Polymyxins [#3 below]
185
Antimicrobials by mechanism of action: Block nucleotide synthesis Drugs?
Sulfonamides, Trimethoprim [#4 below]
186
Antimicrobials by mechanism of action: Block DNA topoisomerases Drugs?
Quinolones [#5 below]
187
Antimicrobials by mechanism of action: Block mRNA synthesis Drugs?
Rifampin [#6 below]
188
Antimicrobials by mechanism of action: Block protein synthesis at 50S ribosomal subunit Drugs?
Chloramphenicol, macrolides, clindamycin, streptogramins (quinipristin, dalfopristin), linezolid [#7]
189
Antimicrobials by mechanism of action: Block protein synthesis at the 30S ribosomal subunit Drugs?
Aminoglycosides, tetracyclines [#8 below]
190
Bacterostatic antibiotics
E rythromycin C lindamycin S ulfamethoxazole T rimethoprim T etracylcines C hloramphenicol (We're ECST aT iC about bacteriostatics )
191
Bacteriocidal antibiotics
V ancomycin F luoroquinolones P enicillin A minoglycosides C ephalosporins M etronidazole V ery F inely P roficient A t C ell M urder
192
Forms of Penicillin
Penicillin G (IV form), Penicillin V (oral form). Prototype Beta-lactam antibiotics.
193
Mechanism of penicillin
1.) Bind penicillin-binding proteins 2.) Block transpeptidase cross-linking of cell wall 3.) Activate autolytic enzymes
194
Mechanism of penicillinase-resistant penicillins: Methicillin, nafcillin, dicoxacillin
Same as penicillin*. Narrow speectrum; penicillinase resistant b/c of bulkier R group. * mechanism of PCN: 1.) Bind penicillin-binding proteins 2.) Block transpeptidase cross-linking of cell wall 3.) Activate autolytic enzymes
195
Mechanism of aminopenicillins: Ampicillin, amoxicillin
Same as penicillin*. Wider spectrum; Penicillinase sensitive. Also combine w/ clavulanic acid (a penicillinase inhibitor) to enhance spectrum. AmO xicillin has greater O ral bioavailability than ampicillin. *Mechanism of PCN: 1.) Bind penicillin-binding proteins 2.) Block transpeptidase cross-linking of cell wall 3.) Activate autolytic enzymes
196
Mechanism of antipseudomonals: Ticarcillin, carbenicillin, piperacillin
Same as penicillin*. Extended spectrum. *Mechanism of penicillin: 1.) Bind penicillin-binding proteins 2.) Block transpeptidase cross-linking of cell wall 3.) Activate autolytic enzymes
197
Clinical use of penicillin
Bactericidal for Gram(+) cocci, Gram(+) rods, Gram(-) cocci, and spirochetes. Not penicillinase resistant.
198
Toxicity of penicillin
Hypersensitivity rxtns. Methicillin: interstitial nephritis.
199
Clinical use of aminopenicillins (ampicillin, amoxicillin)
Extended spectrum penicillin*: certain gram(+) bacteria and gram(-) rods: H aemophilus influenzae, E . coli, L isteria monocytogenes, P roteus mirabilis, S almonella, enterococci (Ampicillin/amoxicillin HELPS kill enterococci) *Think of amp icillin/amoxicillin as AMP ed up penicillin
200
Toxicity of aminopenicillins (ampicillin, amoxicillin)
Hypersensitivity rxtns; Ampicillin rash; Pseudomembranous colitis.
201
Clinical use of: Ticarcillin, carbenicillin, piperacillin
(antipseudomonals -- TCP : T ake C are of P seudomonas) Used for Pseudomonas spp. and gram(-) rods; susceptible to penicillinase; Use w/ clavulinic acid (Beta-lactamase inhibitor).
202
Toxicity of antipseudomonals (Ticarcillin, carbenicillin, piperacillin)
Hypersensitivity rxtns.
203
Mechanism of cephalosporins
Beta-lactam drugs that inhibit cell wall synthesis, but are less susceptible to penicillinases. Bactericidal.
204
Clinical use of 1st generation cephalosporins (Cefazolin, cephalexin)
Gram(+) cocci, P roteus mirabilis, E . c oli, K lebsiella pneumoniae (1st gen = PEcK )
205
Clinical use of 2nd generation cephalosporins (cefoxitin, cefaclor, cefuroxime)
Gram(+) cocci, H aemophilus influenzae, E nterobacter aerogenes, N eisseria spp. P roteus mirabilis, E. c oli, K lebsiella pneumoniae, S erratia marcescens (2nd Gen = HEN PEcKS )
206
Clinical use of 3rd generation cephalosporins (ceftriaxone, cefotaxime, ceftazidime)
Serious gram(-) infxns resistant to other beta-lactams; meningitis (most penetrate the BBB). Examples: Ceftazidime for Pseudomonas Ceftriaxone for gonorrhea
207
Clinical use of 4th generation cephalosporins (Cefepime)
Increased activity against Pseudomonas and gram(+) organisms.
208
Toxicity of cephalosporins
Hypersensitivity rxtn. Cross-hypersensitivvity w/ penicillins occurs in 5-10% of pts. Increased nephrotoxicity of aminoglycosides; disulfiram-like rxtn w/ ethanol (in cephalosporins w/ methylthitetrazole group, e.g., cefamandole)
209
Mechanism of aztreonam
A monobactam resistant to beta-lactamases. Inhibits cell wall synthesis (binds to PBP3). Synergistic w/ aminoglycosides. No cross-allergenicity w/ penicillins.
210
Clinical use of aztreonam
Gram(-) rods - Klebsiella spp., Pseudomonas spp., Serratia spp. No activity against gram(+)'s or anaerobes. For penicillin-allergic pts and those w/ renal insufficiency who cannot tolerate aminoglycosides.
211
Toxcity of Aztreonam
Usually nontoxic; occasional GI upset. No cross-sensitivity w/ penicillins or cephalosporins.
212
Mechanism of Imipenem/cilastatin, meropenem
Imipenem is a broad-spectrum, beta-lactamase-resistant carbapenem. Always administer w/ cilastatin (inhibitor of renal dihydropeptidase I) to decrease inactivation in renal tubules. (With imipenem, the kill is LASTIN' with ciLASTATIN )
213
Clinical use of imipenem/cilastatin, meropenem
Gram(+) cocci, gram(-) rods, and anaerobes. DOC for Enterobacter. The significant side effects limit use to life-threatening infxns, or after other drugs have failed. Meropenem, howevver, has a reduced risk of seizures and is stable to dihydropeptidase I.
214
Toxicity of Imipenem/cilastatin, meropenem
GI distress, skin rash, and CNS toxicity (seizures) @ high plasma levels
215
Mechanism of vancomycin
Inhibits cell wall mucopeptide formation by binding D-ala D-ala portion of cell wall precursors. Bactericidal. Resistance occurs w/ AA change of D-ala D-ala to D-ala D-lac
216
Clinical use of vancomycin
Used for serious, gram(+) multidrug-resistant organisms, including S. aureus and Clostridium difficile (pseudomembranous colitis)
217
Toxicity of vancomycin
N ephrotoxicity, O totoxicity, T hromophlebitis, diffuse flushing - red man syndrome (can largely prevent by pretreatment w/ antihistamines and slow infusion rate) Well toleraterd in general -- does NOT have many problems.
218
Protein synthesis inhibitors: 30S inhibitors
A = A minoglycosides (streptomycin, gentamycin, tobramycin, amikacin) [bacteriostatic] T = T etracyclines [bacteriostatic] (But AT 30 , CCELL (sell) at 50) [*note different specific sites of action of Aminoglycosides and TCNs below]
219
Protein Synthesis Inhibitors: 50S inhibitors
C = C hloramphenicol, C lindamycin [bacteriostatic] E = E rythromycin [bacteriostatic] L = L incomycin [bacteriostatic] L = L inezolid [variable] (But AT 30, CCELL (sell) at 50 ) [note different specific sites of action below]
220
Aminoglycosides (list)
G entamycin N eomycin A mikacin T obramycin S treptomycin (Mean GNATS [mean = amin oglycosides)
221
Mechanism of aminoglycosides (gentamycin, neomycin, amikacin, tobramycin, streptomycin)
Bactericidal; inhibit formation of initiation complex and cause misreading of mRNA. Require O2 for uptake; therefore ineffective against anaerobes. (Mean GNATS canNOT kill anaerobes)
222
Clinical use of aminogyclosides (gentamycin, neomycin, amikacin, tobramycin, streptomycin)
Severe gram (-) rod infxns. Synergistic w/ beta-lactam ABX. Neomycin for bowel surgery.
223
Toxicity of aminoglycosides (gentamycin, neomycin, amikacin, tobramycin, streptomycin)
N ephrotoxicity (especially when used w/ cephalosporins) O totoxicity (especially when used w/ loop diuretics) T eratogen. (Mean GNATS canNOT kill anaerobes)
224
Tetracyclines (list)
Tetracylcine Doxycycline Demeclocycline Minocycline
225
Mechanism of tetracyclines (tetracycline, doxycycline, demeclocyclline, minocycline)
Bacteriostatic; bind to 30S and prevent attachment of aminoacyl-tRNA. Limited CNS penetration. Doxycyline is fecally eliminated and can be used in pts w/ renal failure. Must NOT take w/ milk, antacids, or iron-containing preparations b/c divalent cations inhibit absorption in gut. D emeclocycline is an ADH antagonist (acts as a D iuretic in SIADH)
226
Clinical use of tetracyclines (tetracycline, doxycycline, demeclocyclline, minocycline)
V ibrio cholerae A cne C hlamydia U reaplasma U realyticum M ycoplasma pneumoniae T ularemia H . pylori B orrelia burgdorferi (Lyme dz) R ickettsia (VACUUM TH e B edR oom)
227
Toxicity of tetracyclines (tetracycline, doxycycline, demeclocyclline, minocycline)
GI distress Discoloration of teeth and inhibition of bone growth in children Photosensitivity Contraindicated in pregnancy.
228
Macrolides (list)
Erythromycin, azithromycin, clarithromycin
229
Mechanism of macrolides (Erythromycin, azithromycin, clarithromycin)
Inhibit protein synthesis by blocking translocation; bind to the 23S rRNA of the 50S ribosomal subunit. Bacteriostatic.
230
Clinical use of macrolides (Erythromycin, azithromycin, clarithromycin)
URIs, pneumonias STDs -- gram(+) cocci (streptococcal infxns in pts allergic to penicillin) Mycoplasma Legionella Chlamydia Neisseria
231
Toxicity of macrolides (Erythromycin, azithromycin, clarithromycin)
GI discomfort (most common cause of noncompliance) Acute cholestatic hepatitis Eosinophilia Skin rashes Increases serum concentration of theophyllines, oral anticoagulants.
232
Mechanism of chloramphenicol
Inhibits 50S peptidyltransferase activity. Bacteriostatic.
233
Clinical use of chloramphenicol
Meningitis (Haemophilus influenzae, Neisseria meningitidis, Streptococcus pneumoniae) Conservative use, owing to toxicities.
234
Toxicity of chloramphenicol
Anemia (dose dependent) Aplastic anemia (dose independent) Gray baby syndrome (in premature infants b/c they lack liver UDP-glucuronyl transferase)
235
Mechanism of clindamycin
Blocks peptide bond formation at 50S ribosomal subunit. Bacteriostatic.
236
Clinical use of clindamycin
Tx anaerobic infxns (e.g., Bacteroides fragilis, Clostridium perfringens) (Treats anaerobes above the diaphragm)
237
Toxicity of clindamycin
Pseudomembranous colitis (C. difficile overgrowth) Fever Diarrhea
238
Sulfonamides (list)
Sulfamethoxazole (SMX) Sulfisoxazole Sulfadiazine
239
Mechanism of sulfonamides (sulfamethoxazole (SMX), sulfisoxazole, sulfadiazine)
PABA antimetabolites inhibit dihydropteroate synthetase [see below]. Bacteriostatic.
240
Clinical use of of sulfonamides (sulfamethoxazole (SMX), sulfisoxazole, sulfadiazine)
Gram(+), gram(-), Nocardia, Chlamydia. Triple sulfas or SMX for simple UTI.
241
Toxicity of sulfonamides (sulfamethoxazole (SMX), sulfisoxazole, sulfadiazine)
Hypersensitivity rxtns Hemolysis if G6PD deficient Nephrotoxicity (tubulointerstitial nephritis) Photosensitivity Kernicterus in infants Displace other drugs from albumin (e.g., warfarin)
242
Mechanism of trimethoprim (TMP)
Inhibits bacterial dihydrofolate reductase. Bacteriostatic.
243
Clinical use of trimethoprim (TMP)
Used in combination w/ sulfonamides (trimethoprim-sulfamethoxazole [TMP-SMX]), causing sequential block of folate synthesis. Combination used for recurrent UTIs, Shigella, Salmonella, Pneumocystis jiroveci pneumonia.
244
Toxicity of trimethoprim (TMP)
Megaloblastic anemia Leukopenia Granulocytopenia (may alleviate w/ supplemental folinic acid) (Trimethoprim = TMP : T reats M arrow P oorly)
245
Sulfa drug allergies -- what do you need to avoid?
Pts who do not tolerate sulfa drugs should not be given sulfonamides or other sulf drugs such as: Sulfasalazine Sulfonylureas Thiazide diuretics Acetazolamide Furosemide
246
Fluoroquinolones (list)
Ciprofloxacin Norfloxacin Ofloxacin Sparfloxacin Moxifloxacin Gatifloxacin Enoxacin [above are fluoroquinolones] Nalidixic acid [a quinolone]
247
Mechanism of fluoroquinolones
Inhibit DNA gyrase (topoisomerase II). Bactericidal. Must not be taken w/ antacids.
248
Clinical use of fluoroquinolones
Gram(-) rods of urinary and GI tracts (including Pseudomonas), Neisseria, some gram(+) organisms
249
Toxicity of fluoroquinolones
GI upset, superinfections, skin rashes, HA, dizziness. Contraindicated in pregnant women and in children b/c animal studies show damage to cartilage. Tendonitis and tendon rupture in adults; leg cramps and myalgias in kids. (FlouroquinoLONES hur the attachments to your BONES )
250
Mechanism of metronidazole
Forms toxic metabolites in the bacterial cell that damage DNA. Bactericidal, antiprotozoal.
251
Clinical use of metronidazole
Treats: G iardia E ntamoeba T richomonas G ardnerella vaginalis A naerobes (Bacteroides, Clostridium) Used w/ bismuth and amoxicillin (or TCN) for triple therapy against H. P ylori (GET GAP on the METRO !) Treats anaerobic infxns below the diaphragm.
252
Toxicity of metronidazole
Disulfiram-like rxtn w/ alcohol Headache Metallic taste
253
Polymyxins (list)
Polymyxin B Polymyxin E
254
Mechanism of polymyxins
Bind to cell membranes of baccteria and disrupt their osmotic properties. Polymyxins are cationic, basic proteins that act like detergents. (MYXins MIX up membranes)
255
Clinical use of polymyxins
resistant gram(-) infxns
256
Toxicity of polymyxins
Neurotoxicity, acute renal tubular necrosis
257
Antimycobacterial drugs: for M. tuberculosis
Prophylaxis: Isoniazid Tx: R ifampin I soniazid P yrazinamide E thambutol (RIPE for treatment)
258
Antimycobacterial drugs: for M. avium-intracellulare
Prophylaxis: Azithromycin Tx: Azithromycin Rifampin Ethambutol Streptomycin
259
Antimycobacterial drugs for M. leprae
Tx: Dapsone Rifampin Clofazimine
260
Anti-TB drugs
S treptomycin, P yrazinamide, I soniazid (INH ), R ifampin, E thambutol (INH-SPIRE [inspire]) Cycloserine (2nd-line therapy)
261
Side effects of anti-TB drugs
Important SE of ethambutol: optic neuropathy (red-green color blindness) For other drugs: hepatotoxicity.
262
Mechanism of isoniazid (INH)
Decreases synthesis of mycolic acids. *note that there are different INH half-lives in fast vs. slow acetylators.
263
Clinical use of isoniazid (INH)
Mycobacterium tuberculosis. The only agent used as solo prophylaxis against TB.
264
Toxicity of isoniazid (INH)
Neurotoxicity, hepatotoxicity. Pyridoxine (Vitamin B6) can prevent neurotoxicity. (INH I njures N eurons and H epatocytes)
265
Mechanism of rifampin
Inhibits DNA-dependent RNA polymerase
266
Clinical use of rifampin
Mycobacterium tuberculosis. Delays resistance to dapsone when used for leprosy. Used for meningococcal prophylaxis and chemoprophylaxis in contacts of children w/ Haemophilus influenzae type B.
267
Toxicity of rifampin
Minor hepatotoxicity and drug interactions (induces P-450) Orange body fluids (nonhazardous side effect)
268
Rifampin's 4 R's
R NA polymerase inhibitor R evs up microsomal P-450 R ed/orange body fluids R apid resistance if used alone
269
Most common resistance mechanism for: Penicillins/cephalosporins
Beta-lactamase cleavage of beta-lactam ring, or altered PBP in cases of MRSA or penicillin-resistant S. pneumoniae.
270
The following is the most common mechanism of resistance for what drug? Beta-lactamase cleavage of beta-lactam ring, or altered PBP in cases of MRSA or penicillin-resistant S. pneumoniae.
Penicillins/cephalosporins
271
Most common resistance mechanism for: Aminoglycosides
Modification via acetylation, adenylation, or phosphorylation.
272
The following is the most common mechanism of resistance for what drug? Modification via acetylation, adenylation, or phosphorylation.
Aminoglycosides
273
Most common resistance mechanism for: Vancomycin
Terminal D-ala of cell wall component replaced with D-lac, decreased affinity.
274
The following is the most common mechanism of resistance for what drug? Terminal D-ala of cell wall component replaced with D-lac, decreased affinity.
Vancomycin
275
Most common resistance mechanism for: Chloramphenicol
Modification via acetylation
276
The following is the most common mechanism of resistance for what drug? Modification via acetylation
Chloramphenicol
277
Most common resistance mechanism for: Macrolides
methylation of rRNA near erythromycin's ribosome-binding site
278
The following is the most common mechanism of resistance for what drug? methylation of rRNA near erythromycin's ribosome-binding site
Macrolides
279
Most common resistance mechanism for: Tetracycline
Decreased uptake or increased transport out of cell.
280
The following is the most common mechanism of resistance for what drug? Decreased uptake or increased transport out of cell.
Tetracycline
281
Most common resistance mechanism for: Sulfonamides
Altered enzyme (bacterial dihydropteroate synthetase), decreased uptake, or increased PABA synthesis.
282
The following is the most common mechanism of resistance for what drug? Altered enzyme (bacterial dihydropteroate synthetase), decreased uptake, or increased PABA synthesis.
Sulfonamides
283
Most common resistance mechanism for: Quinolones
Altered gyrase or reduced uptake.
284
The following is the most common mechanism of resistance for what drug? Altered gyrase or reduced uptake.
Quinolones
285
Nonsurgical antimicrobial prophylaxis of: meningococcal infxn
Rifampin (DOC), minocycline
286
Nonsurgical antimicrobial prophylaxis of: gonorrhea
Ceftriaxone
287
Nonsurgical antimicrobial prophylaxis of: syphilis
Benzathine penicillin G
288
Nonsurgical antimicrobial prophylaxis of: Hx of recurrent UTIs
TMP-SMX
289
Nonsurgical antimicrobial prophylaxis of: Pneumocystis jiroveci pneumonia
TMP-SMX (DOC), aerosolized pentamidine.
290
Nonsurgical antimicrobial prophylaxis of: endocarditis w/ surgical or dental procedures
Penicillins.
291
Tx of highly resistant bacteria
MRSA: vancomycin
292
Mechanism of Amphotericin B
Binds ergosterol (unique to fungi); Forms membrane pores that allow leakage of electrolytes. (Amphotear acin 'tears' holes in fungal membranes by forming pores) [on left, below]
293
Clinical use of Amphotericin B
Use for wide spectrum of systemic mycoses. Cryptococcus, Blastomyces, Coccidioides, Aspergillus, Histoplasma, Candida, Mucor (systemic mycoses). Intrathecally for fungal meningitis; does not cross BBB.
294
Toxicity of Amphotericin B
Fever/chills (shake and bake), hypotension, nephrotoxicity, arrhythmias, anemia, IV phlebitis (amphotericin = amphoterrible). Hydration reduces nephrotoxicity. Liposomal amphotericin reduces toxicity.
295
Mechanism of Nystatin
Binds to ergosterol, disrupting fungal membranes. Too toxic for systemic use. [on left w/ amphotericin, below]
296
Clinical use of nystatin
Swish and swallow for oral candidiasis (thrush); topical for diaper rash or vaginal candidiasis.
297
Azoles (list)
Fluconazole
298
Mechanism of azoles
Inhibit fungal sterol (ergosterol) synthesis [below, top/middle]
299
Clinical use of azoles
Systemic mycoses. Fluconazole for cyptococcal meningitis in AIDS pts (b/c it can cross the BBB) and candidal infxns of all types (i.e., yeast infxns). Ketoconazole for Balstomyces, Coccidioides, Histoplasma, Candida albicans, hypercortisolism. Clotrimazole and miconazole for topical fungal infxns.
300
Toxicity of azoles
Hormone synthesis inhibition (gynecomastia), liver dysfunction (inhibits cytochrome P-450), fever, chills
301
Flucytosine mechanism
Inhibits DNA synthesis by conversion to 5-fluorouracil [below, middle]
302
Clinical use of flucytosine
Used in systemic fungal infxns (e.g., Candida, Cryptococcus) in combination w/ amphotericin B
303
Toxicity of flucytosine
Nausea, vomiting, diarrhea, bone marrow suppression
304
Mechanism of Caspofungin
Inhibits cell wall synthesis by inhibiting synthesis of beta-glucan. [not included in image of anti-fungal mechanisms]
305
Clinical use of caspofungin
Invasive aspergillosis
306
Toxicity of caspofungin
GI upset, flushing.
307
Mechanism of terbinafine
Inhibits the fungal enzyme squalene epoxidase. [below, top/right]
308
Clinical use of terbinafine
Used to Tx dermatophytoses (especially onychomycosis)
309
Mechanism of griseofulvin
Interferes w/ microtubule fxn; disrupts mitosis. Deposits keratin-containing tissues (e.g., nails). [below, bottom/right]
310
Clinical use of griseofulvin
Oral Tx of superficial infxns; inhibits growth of dermatophytes (tinea, ringworm)
311
Toxicity of griseofulvin
Teratogenic, ccarcinogenic, confusion, HA, induces P-450 (increasing warfarin metabolism).
312
Mechanism of amantadine
Blocks viral penetration/uncoating (M2 protein); may buffer pH of endosome. (A man to dine [amantadine] takes of his coat .) Also causes the release of dopamine from intact nerve terminals. [below, top/right]
313
Clinical use of amantadine
Prophylaxis and Tx for influenza A; Parkinson's Dz. (A mantadine blocks influenza A and rubellA , and causes problems w/ the cerebellA )
314
Toxicity of amantadine
Ataxia, dizziness, slurred speech. (A mantadine blocks influenza A and rubellA , and causes problems w/ the cerebellA ) Rimantidine is a derivative w/ fewer CNS side effects (does not cross BBB)
315
Mechanism of resistance to amantadine
Mutated M2 protein. 90% of all influenza A strains are resistant to amantadine, so not used.
316
Mechanism of: Zanamivir, oseltamivir
Inhibit influenza neuraminidase, decreasing the release of progeny virus. [below, bottom/left: Neuraminidase inhibitors]
317
Clinical use of Zanamivir, oseltamivir
Both influenza A and B
318
Mechanism of ribavirin
Inhibits synthesis of guanine nucleotides by competitively inhibiting IMP dehydrogenase. [not included in figure, but acts at point of NA synthesis, bottom/right]
319
Clinical use of ribavirin
RSV Chronic hepatitis C
320
Toxicity of ribavirin
Hemolytic anemia. Severe teratogen.
321
Mechanism of acyclovir
Monophosphorylated by HSV/VZV thymidine kinase. Guanosine analog. Triphosphate formed by cellular enzymes. Preferentially inhibits viral DNA polymerase by chain termination. [fits w/ NA analogs below, bottom/right]
322
Clnicial use of acyclovir
HSV, VZV, EBV. Used for HSV-induced mucocutaneous and genital lesions as well as for encephalitis. Prophylaxis in immunocompromised pts. For herpes zoster, use a related agent (famciclovir). No effect on latent forms of HSV and VZV.
323
Toxicity of acyclovir
Generally well-tolerated.
324
Mechanism of resistance to acyclovir
Lack of thymidine kinase
325
Mechanism of ganciclovir
5'-monophosphate formed by a CMV viral kinase or HSV/VZV thymidine kinase. Guanosine analog. Triphosphate formed by cellular kinases. Preferentially inhibits viral DNA polymerase. [fits in w/ NA analogs below, bottom/right]
326
Clinical use of ganciclovir
CMV, especially in immunocompromised pts
327
Toxicity of ganciclovir
Leukopenia, neutropenia, thrombocytopenia, renal toxicity. More toxic to host enzymes than acyclovir.
328
Mechanism of resistance to ganciclovir
Mutated CMV DNA polymerase or lack of viral kinse.
329
Mechanism of foscarnet
Viral DNA polymerase inhibitor that binds to the pyrophosphate-binding site of the enzyme. Does not require activation by viral kinase. (FOS carnet = pyroFOS phate analog) [would fit into DNA synthesis on bottom/right]
330
Clinical use of foscarnet
CMV retinitis in immunocompromised pts when ganciclovir fails; acyclovir-resistant HSV.
331
Toxicity of foscarnet
Nephrotoxicity.
332
Mechanism of resistance to foscarnet
Mutated DNA polymerase.
333
HIV therapy: Protease inhibitors (list)
Saquinavir Ritonavir Indinavir Nelfinavir Amprenavir [all protease inhibitors end in -avir ] (NAVIR (never) TEASE a proTEASE )
334
HIV therapy: Mechanism of protease inhibitors
Inhibit maturation of new virus by blocking protease in progeny of virus.
335
HIV therapy: Toxicity of protease inhibitors
GI intolerance (nausea, diarrhea) Hyperglycemia Lipodystrophy Thrombocytopenia (indinavir)
336
HIV therapy: Reverse transcriptase inhibitors --> nucleosides (list)
Zidovudine (ZDV, formerly AZT) Didanosine (ddI) Zalcitabine (ddC) Stavudine (d4T) Lamivudine (3TC) Abacavir (Have you dined (vudine ) with my nuclear (nucleosides ) family?)
337
HIV therapy: Reverse transcriptase inhibitors --> non-nucleosides (list)
N evirapine, E favirenz, D elaviridine (N ever E ver D eliver nucleosides.)
338
HIV therapy: Mechanism of reverse transcriptase inhibitors
Preferentially inhibit reverse transcriptase of HIV; prevent incorporation of DNA copy of viral genome into host DNA. [below, bottom/right]
339
HIV therapy: Toxicity of reverse transcriptase inhibitors
Bone marrow suppression* (neutropenia, anemia) Peripheral neuropathy Lactic acidosis (nucleosides) Rash (non-nucleosides) Megaloblastic anemia (ZDV) *GM-CSF and erythropoietin can be used to reduce BM suppression.
340
HIV therapy: Clinical use of reverse transcriptase inhibitors
Highly active antiretroviral therapy (HAART) generally entails combination Tx w/ protease inhibitors and reverse transcriptase inhibitors. Initiated when pts have low CD4 counts (
341
HIV therapy: Fusion inhibitor (there's one -- what is it?)
Enfuvirtide
342
HIV therapy: Mechanism of fusion inhibitors (enfuvirtide)
Bind viral gp41 subunit; inhibit conformational change required for fusion w/ CD4 cells. Therefore block entry and susequent replication.
343
HIV therapy: Toxicity of fusion inhibitors (enfuvirtide)
Hypersensitivity rxtns Rxtns at subcutaneous injection site Increased risk of bacterial pneumonia
344
HIV therapy: Clinical use of fusion inhibitors (enfuvirtide)
In pts w/ persistent viral replication in spite of antiretroviral Tx. Used in combination w/ other drugs.
345
Mechanism of interferons (as antimicrobials)
Glycoproteins from human leukocytes that block various stages of viral RNA and DNA synthesis. Induce ribonuclease that degrades viral mRNA.
346
Clinical use of interferons
IFN-alpha: chronic hepatitis B and C, Kaposi's sarcoma IFN-beta: MS IFN-gamma: NADPH oxidase deficiency
347
Toxicity of interferons
Neutropenia
348
Antibiotics to avoid in pregnancy (list -- what are they, and why for each one?)
S ulfonamides -- kernicterus
