Pharmacology Flashcards
(225 cards)
1
Q
What % of patients with penicillin allergy will have a cephalosporin allergy
A
0.1
2
Q
How do the general antimicrobial spectra differ between 1 sc, 2”d, 3rd, and 4th generation quinolones
A
- 1st generation {nalidixic acid): only gram negative, no Pseudomonas coverage.
- 2nd generation ( ciprofloxacin, ofloxacin): Staph aureus but not pneumococcus; some gram negative, including atypicals. Pseudomonas
- 3rd generation (levofloxacin): gram negative, including Pseudomonas; gram positive,including Staph aureus and pneumococcus; expanded atypical coverage.
- 4th generation (gatifloxacin, moxifloxacin): same as 3rd generation with enhanced coverage of pneumococcus decreased activity against Pseudomonas.
3
Q
What is the best time to begin prophylactic antibiotic therapy for elective surgery
A
1 hour prior to the operation.
4
Q
What % of cases of antibiotic-associated diarrhea are due to Clostridium difficile
A
10- 20°/o.
5
Q
What is the incidence of C. diff in cases of antibiotic-associated diarrhea?
A
10-20%.
6
Q
What is the treatment for otosyphilis?
A
2-4 million U of benzathine penicillin IM every week for at least 3 weeks (up to 1 year) or 10 million U of penicillin G IV every day for 10 days followed by 2-4 million U of IM benzathine penicillin every week for 2 weeks plus prednisone 40-60 mg every day for 2-4 weeks followed by a taper.
7
Q
What percent of all adverse drug reactions among hospitalized patients can be attributed to antibiotics?
A
25%.
8
Q
After aminoglycoside treatments for Meniere’s disease, when is the usual onset of disequilibrium?
A
4 days after treatment.
9
Q
What is the incidence of rash after taking penicillin
A
5%.
10
Q
What percent of patients with mononucleosis will develop a rash after taking amoxicillin?
A
50%.
11
Q
What % of these patients will develop a rash the next time they take penicillin
A
50%.
12
Q
What % of patients with mononucleosis will develop a rash after taking amoxicillin
A
50%.
13
Q
Approximately what percent of C. difficile cases occur after taking quinolones?
A
55%.
14
Q
How long may the onset of pseudomembranous enterocolitis begin after initiation of antibiotics?
A
6 weeks.
15
Q
How long may the onset of pseudomembranous enterocolitis begin after initiation of antibiotics
A
6 weeks.
16
Q
What can happen if a quinolone is given to a patient dependent on benzodiazepines?
A
Acute withdrawal symptoms from the benzodiazepines.
17
Q
Aminoglycosides are effective against what bacteria
A
Aerobic gram negative bacilli (including Pseudomonas aeruginosa), enterococci, staphylococci and streptococci.
18
Q
Aminoglycosides are effective against what bacteria?
A
Aerobic gram-negative bacilli (including Pseudomonas aeruginosa), enterococci, staphylococci, and streptococci.
19
Q
Mitochondrial mutations have been found to produce enhanced sensitivity to the ototoxic effects of which medications?
A
Aminoglycosides.
20
Q
Which antibiotics potentiate muscle blockade induced by curare
A
Aminoglycosides.
21
Q
Which penicillin analogue can be given to patients with a history of anaphylaxis after taking penicillin?
A
Aztreonam.
22
Q
Which penicillin analogue can be given to patients with a history of anaphylaxis after taking penicillin
A
Aztreonam.
23
Q
What region of the inner ear is most susceptible to permanent loss of hair cells?
A
Basal turn of the cochlea.
24
Q
How do aminoglycosides exert their toxic effects on the outer hair cells of the inner ear?
A
Bind to the plasma membrane and displace calcium and magnesium; once transported into the cell, bind with phosphatidylinositol, causing disruption of the plasma membrane and inhibition of inositol triphosphate, resulting in cell death.
25
Which 1st generation cephalosporin has the longest half-life
Cefazolin (Ancef or Kefzol).
26
Which first-generation cephalosporin has the longest half-life?
Cefazolin.
27
Which 3rd generation cephalosporin is associated with possible clotting impairment
Cefoperazone (Cefobid).
28
Which antibiotic agents are bacteriostatic
Chloramphenicol, clindamycin, erythromycin, sulfonamides, tetracyclines and trimethoprim.
29
Why are iodine solutions superior to chlorhexidine as a surgical antiseptic
Chlorhexidine is not effective against viruses and fungi.
30
Which antibiotics are most commonly associated with development of Clostridium difftcile
Clindamycin, cephalosporins, and penicillins.
31
Which medications, when given concurrently with a quinolone, significantly increase the risk of quinolone-associated tendon rupture?
Corticosteroids.
32
What is the alternate therapy and when should it be initiated?
Dapsone should be used when severe reactions (e.g., skin blistering, mucosal involvement, or anaphylaxis) to TMP-SMX occur.
33
Which method is responsible for the resistance of S. pneumoniae to penicillins?
Decreased penicillin-binding protein affinity.
34
What problem has arisen with the increase use of vancomycin
Development of vancomycin resistant enterococci (VRE).
35
Which of these attains the highest blood levels
Dicloxacillin.
36
Which of these attains the highest blood levels?
Didoxacillin.
37
What is the most important factor determining risk of ototoxicity with use of aminoglycosides?
Duration of therapy \> 10 days.
38
What is the most important factor determining risk of ototoxicity with use of aminoglycosides
Duration of therapy \>I Odays.
39
Which macrolide does not cover H.injluenzae?
Erythromycin.
40
Which macrolide does not cover Haemophilus injluenzae
Erythromycin.
41
What is the primary problem of 1M penicillin therapy for otosyphilis?
Fails to achieve treponemicidal levels in the cerebrospinal fluid (CSF).
42
T /F: Closed suction drainage decreases the incidence of wound infection in clean cases.
False.
43
What is the Jarisch-Herxheimer reaction?
Fever and flulike symptoms beginning within 4 hours of commencing treatment for secondary syphilis.
44
What drug has shown equal efficacy as vancomycin for the treatment of C. diff infections with a lower rate of recurrence (15% vs. 25% for vancomycin)?
Fidaxomicin.
45
Which class of antibiotic is most commonly associated with the development of C. diff?
Fluoroquinolones.
46
What is Red Man's Syndrome
Flushing of the face and neck, pruritus and hypotension associated with rapid infusion of vancomycin and subsequent release of histamine.
47
What is Red Man's Syndrome?
Flushing of the face and neck, pruritus and hypotension associated with rapid infusion of vancomycin, and subsequent release of histamine.
48
In patients with postoperative pneumonia, empiric monotherapy should cover which organisms
Gram negative organisms.
49
In emergency surgery following trauma, which organisms are most likely to cause serious sepsis
Gram-negative bacteria.
50
In patients with postoperative pneumonia, empiric monotherapy should cover which organisms?
Gram-negative organisms.
51
Vancomycin is effective against which bacteria
Gram-positive cocci, including methicillin-resistant Staphylococcus aureus (MRSA), Staphylococcus epidermidis, enterococci, diphtheroids and Clostridium difficile.
52
Vancomycin is effective against which bacteria?
Gram-positive cocci, including methicillin-resistant Staphylococcus aureus (MRSA), Staphylococcus epidermidis, enterococci, diphtheroids, and C. difficile.
53
What is the incidence of bone marrow suppression with chloramphenicol
I :24,000.
54
What are the four processes of bacterial resistance to antibiotics?
Inability of the antibiotics to penetrate the bacterial cell, -lactamase production, altered penicillin-binding protein affinity, and methicillin-resistance pattern.
55
What can be done to overcome this method of resistance?
Increase the concentration of the drug.
56
Why is the mg/kg dosage of gentamicin given to infants higher than that given to older children?
Infants have a higher extracellular fluid volume per weight.
57
Why is the mg/kg dosage of gentamicin given to infants higher than that given to older children
Infants have a higher extracellular fluid volume per weight.
58
What is the mechanism of action of quinolones?
Inhibition of DNA gyrase, which is needed to package DNA into dividing bacteria.
59
What other therapy has been shown to decrease the risk of recurrence of C. diff?
Intravenous infusion of neutralizing monoclonal antibodies to C. difficile toxins A and B.
60
Why is ciprofloxacin contraindicated in children?
It has been shown to cause arthropathy of the weight-bearing joints in immature animals.
61
What are the features of the epidemic strain of C. diff (Bt/NAPt/027) that set it apart from other strains?
It produces 16-23 x the amount of toxins A and B; produces a third toxin (binary toxin CDT); and has high levels of fluoroquinolone resistance.
62
What is the incidence of wound infections in clean, clean-contaminated, contaminated and dirty cases
Less than 2%, 1 O%, 20% and 40%, respectively.
63
What perioperative factors are associated with an increased risk of postoperative wound infection
Long preoperative hospitalization; no preoperative shower; early shaving of the operative site; hair removal; and prior antibiotic therapy.
64
Which penicillins are most active against S. aureus?
Methicillin, oxacillin, dicloxacillin, and nafcillin.
65
Which penicillins are most active against Staphylococcus aureus
Methicillin, oxacillin, dicloxacillin, nafcillin.
66
Which of these is not active against Streptococcus pneumoniae?
Methicillin.
67
Which of these is not active against Streptococcus pneumoniae
Methicillin.
68
What is the initial drug of choice for treating C.diJJicile?
Metronidazole.
69
Which quinolone carries the highest risk for QTc prolongation and CNS toxicity?
Moxifloxacin.
70
What is the best medication to eradicate nasal colonization with methicillin-resistantS. aureus?
Mupirocin.
71
What is the best medication to eradicate nasal colonization with methicillin-resistant Staphylococcus aureus
Mupirocin.
72
Which of these is best for patients with renal failure?
Nafcillin.
73
Which of these is best for patients with renal failure
Nafcillin.
74
What is the mechanism of action of aminoglycoside ototoxicity
Primarily damage to the outer hair cells, first to the basal tum of the cochlea.
75
What medication extends the half-life and facilitates CSF penetration of penicillin?
Probenecid.
76
How do organisms inactivate penicillin
Produce beta-lactamase.
77
How do organisms inactivate penicillin?
Produce-lactamase.
78
What risks are associated with the use of aminoglycosides
Prolonged neuromuscular blockade, ototoxicity and nephrotoxicity.
79
What risks are associated with the use of aminoglycosides?
Prolonged neuromuscular blockade, ototoxicity, and nephrotoxicity.
80
What organisms are covered by amoxicillin and ampicillin that are not covered by penicillin
Proteus, E. Coli, Haemophilus influenzae.
81
What organisms are covered by amoxicillin and ampicillin that are not covered by penicillin?
Proteus, Escherichia coli} Haemophilus in.fluenzae.
82
Which medications can be used to treat people exposed to meningococcus?
Rifampin, ciprofloxacin, or ceftriaxone.
83
Which medications can be used to treat people exposed to meningococcus
Rifampin, ciprofloxacin, or ceftriaxone.
84
Which organisms can produce fl-lactamase?
S. aureus, H. infiuenzae, Moraxella catarrhalis, and oral anaerobes.
85
What is the sensitivity and specificity of testing for C. diff toxins A and B with ELISA?
Sensitivity 63-99%; specificity 93-100%.
86
Wound infections that occur in clean operations are most commonly caused by what organisms
Staphylococci.
87
Which organisms can produce beta-lactamase
Staphylococcus aureus, Haemophilus in.fluenzae, Moraxella catarrhalis, oral anaerobes.
88
What organisms do penicillin G and V cover
Streptococcal pyogenes, Streptococcal pneumococcus, Actinomyces, oral anaerobes.
89
What organisms do penicillin G and V cover?
Streptococcal pyogenes} Streptococcal pneumoniae} Actinomyces, oral anaerobes.
90
What characteristic is common to clavulanate, sulbactam and tazobactam
They are all beta-lactamase inhibitors.
91
What characteristic is common to clavulanate, sulbactam, and tazobactam?
They are all P-lactamase inhibitors.
92
What is the mechanism of action of quinolones
They inhibit DNA gyrase, which is needed to package DNA into dividing bacteria.
93
Why do hematomas increase the risk of infection
They prevent fibroblast migration and capillary formation.
94
Which penicillin derivatives are active against Pseudomonas
Ticarcillin-clavulanate (Timentin), piperacillin-tazobactam (Zosyn).
95
Which penicillin derivatives are active against Pseudomonas?
Ticarcillin-clavulanate and piperacillin-tazobactam.
96
What is the drug of choice for the prophylaxis of Pneumocystis carinii infections in patients with HIV?
TMP-SMX.
97
What antibiotic is effective for treatment of Wegener's granulomatosis?
Trimethoprim/sulfamethoxazole (TMP jSMX).
98
True/False: The rate of colonization of hospitalized patients with Clostridium diJJicile increases in proportion to the patient's length of stay.
True.
99
True/False: The incidence of community-acquired C. diJJicile is higher in patients taking H 2 blockers and proton pump inhibitors.
True.
100
T/F: The dose of metronidazole must be modified for patients with significant liver disease
True.
101
What is an alloantigen?
A human antigen from a different individual.
102
What is an alloantigen?
A human antigen from a different individual.
103
What is a proto-oncogene and what is an oncogene?
A proto-oncogene participates in normal cellular signaling, transduction, and transcription; an oncogene is a mutant allele of a proto-oncogene.
104
What is an antisense drug?
A small, single-stranded nucleotide complementary to a target mRNA molecule that binds to mRNA and halts transcription.
105
What is the most common toxicity of methotrexate?
Abnormal liver function.
106
What are the advantages of using adenovirus?
Adenovirus is highly infective of both quiescent and actively dividing cells, has a known tropism for cells of the upper aerodigestive tract, and can carry large genes.
107
What viruses are employed in head and neck gene therapy?
Adenovirus, adena-associated virus, herpes virus, retroviruses, and vaccinia virus.
108
What is allovectin-7?
An alloantigen that encodes for class I MHC HLA-B7. It is plasmid DNA with a liposome vector that is injected directly into the tumor. Partial response without toxicity has been demonstrated in Phase III trials for stages 3 and 4 melanoma.
109
What is allovectin-7?
An alloantigen that encodes for class I MHC HLA-B7. It is plasmid DNA with a liposome vector that is injected directly into the tumor. Partial response without toxicity has been demonstrated in Phase III trials for stages 3 and 4 melanoma.
110
Where does the adeno-associated virus vector insert its DNA in the host cell?
At the 19q13-4 location.
111
What are the problems with using retroviruses?
Can only infect actively dividing cells, are permanently integrated into the host cell's genome, and randomly insert into the host genome.
112
What are some physical methods of gene transfer?
Cationic liposomes, plasmid DNA, ballistic particle, calcium-phosphate-induced uptake, and electroporation.
113
What is the most effective chemotherapeutic therapy for anaplastic thyroid cancer?
Doxorubicin with valproic acid.
114
What is the most effective chemotherapeutic therapy for anaplastic thyroid cancer?
Doxorubicin with valproic acid.
115
What is immunologic gene therapy?
Enhancement of an immune response specifically against tumor-associated antigens using viral vectors.
116
What is immunologic gene therapy?
Enhancement of an immune response specifically against tumor-associated antigens using viral vectors.
117
What is adoptive T-cell immunotherapy?
Ex vivo enhancement of tumor immunogenicity; lymphocytes are removed from the patient then reinfused after in vitro activation against the patient's own tumor cells.
118
What is adoptive T-cell immunotherapy?
Ex vivo enhancement of tumor immunogenicity; lymphocytes are removed from the patient then reinfused after in vitro activation against the patient's own tumor cells.
119
How does the herpes simplex virus-thymidine kinase gene (HSV-tk) work?
Expresses a viral thymidine kinase that is foreign to mammalian cells but phosphorylates the drug ganciclovir into a compound that terminates DNA synthesis in tumor cells.
120
What are the potential side effects of interferon a-2b?
Fever, weight loss, liver enzyme elevation, and DIC.
121
What does the adenovirus vector do once it enters the host cell?
Forms a nonreplicating, extrachromosomal entity called an episome that persists for 7-42 days.
122
What are the potential side effects of cyclophosphamide?
Hemorrhagic cystitis, leukopenia, sterility, and malignancies of the urinary tract.
123
What are the mechanisms of action of interferon a-2b?
Inhibit epithelial cell migration and proliferation and inhibit growth factor.
124
What is the mechanism of action of methotrexate?
Inhibits dihydrofolate reductase, interfering with DNA synthesis, repair, and replication.
125
Other than corticosteroids, what medications can be used to treat hemangiomas?
Interferon a-2a or -2b.
126
What are the problems with physical methods of gene transfer?
Lack of specificity and extremely low efficiency.
127
What are the two most common tumor suppressor genes under investigation for treatment of head and neck cancers?
P53 and p16.
128
How is isotretinoin effective in the treatment of SCCA of the head and neck?
Reduces the incidence of second primary tumors.
129
How is isotretinoin effective in the treatment of SCCA of the head and neck?
Reduces the incidence of second primary tumors.
130
What are the five major approaches of gene transfer, and which is most common?
Replacement of mutated tumor suppressor genes, introduction of toxic/suicide genes, immunomodulation (most common), delivery of antisense nucleotides, and cytolytic viral therapy.
131
What are the characteristics of an ideal oncolytic virus?
Selective for infection and lysis of cancer cells; stimulates a potent antitumor response with limited local/systemic toxicity.
132
What problems may result from insertion at this location?
This location is associated with chronic B-cell leukemias and integration into both copies of chromosome 19 may lead to cell death.
133
What drug targets the BRAF V6ooE mutation in melanoma and has shown significantly improved survival compared with dacarbazine?
Vemurafenib.
134
What drug targets the BRAF V6ooE mutation in melanoma and has shown significantly improved survival compared with dacarbazine?
Vemurafenib.
135
What are the two main categories of gene delivery agents?
Viral and nonviraljphysical.
136
What is the appropriate tetanus prophylaxis for a patient with a tetanus-prone wound, who has not been previously immunized?
0.5 mL absorbed toxoid and 250 units of human tetanus immune globulin.
137
What is the proper tetanus prophylaxis for a patient with a tetanus-prone wound, who last received a booster 7 years ago?
0.5 mL absorbed toxoid.
138
In a nonacute setting, what is the maximum useful amount of calcium supplementation?
2 g of calcium per day.
139
Dr. Mark Beers found that hospitals made mistakes when recording the medications of elderly patients being admitted to the hospital what percent of the time?
60%.
140
What are the Beers criteria?
A list of medications that tend to cause increased side effects in the elderly.
141
What is the appropriate calcium supplementation if the maximum amount of calcium has already been given and the patient is still hypocalcemic?
Calcitriol or other vitamin D preparations should be added.
142
What effect does zinc have on viral upper respiratory tract infections?
Decreases the duration of symptoms.
143
What are the most widely used agents for treatment of acute migraine?
Ergotamine tartrate and sumatriptan.
144
Which comorbid conditions are contraindications to use of sumatriptan?
Hypertension and coronary artery disease.
145
What is the effect of adrenergic blockers on the lower esophageal sphincter pressure?
Increases it.
146
Tricyclic antidepressants are most likely to benefit patients with tinnitus who have what other problem?
Insomnia.
147
What is the best agent for rapid surgical preparation of thyrotoxic patients?
Long-acting-blocker.
148
In a patient with chronic obstructive pulmonary disease (COPD), which beta-blocker would be preferred: propranolol or metoprolol?
Metoprolol.
149
What is an absolute contraindication to treatment of lymphatic malformations with OK-432?
Penicillin allergy.
150
When is exogenous T4 used in patients with thyroid carcinoma?
Postoperatively in patients with TSH-dependent carcinomas (follicular, papillary, and Hiirthle cell).
151
What medication is most commonly used to treat hyperthyroidism during pregnancy?
Propylthiouracil (PTU).
152
A 26-year-old man with frequent migraines is requesting medication for migraine prevention. He is otherwise healthy but reports difficulty exercising secondary to cough. He has had an allergic reaction to a tricyclic antidepressant in the past. What test should be ordered prior to starting him on migraine prophylaxis?
Pulmonary function test.
153
What medication can be given as an alternate to thyroid hormone withdrawal prior to radioiodine therapy?
Recombinant human TSH.
154
What is the medical treatment for otosclerosis?
Sodium fluoride, vitamin D.
155
Prior to radioiodine therapy, which medications should be discontinued and at what time?
T3, 1week before; T4, 4-6 weeks before; Propylthiouracil, 2 weeks before.
156
What are the most widely used agents for prophylaxis of migraine?
Tricyclic antidepressants,-blockers, anticonvulsants, and calcium antagonists.
157
What are the indications for migraine prophylaxis?
Two or more migraines a week and/ or abortive treatment inadequate.
158
What is the prevalence of CYP2D6 poor metabolizers?
7-10% Caucasians; less commonly found in African Americans (3%) and Asians (1%).
159
Which nonsteroidal anti-inflammatory drug (NSAID) has the lowest risk of gastrointestinal side effects?
Ibuprofen.
160
When should proton pump inhibitors be used in conjunction with NSAIDs?
In patients with a previous history of a gastrointestinal event and/ or patients taking aspirin, steroids, or warfarin.
161
What effect can the maximum daily dose of acetaminophen have on the international normalized ratio (INR) in patients taking warfarin?
INR may increase.
162
Ultra-rapid CYP2D6 metabolizers are more commonly found in which areas of the world?
Middle East and North Mrica.
163
Tramadol is particularly effective for which type of pain?
Neuropathic.
164
What drugs are the strongest inhibitors to the CYP2D6 enzyme, rendering opioids less effective?
Selective serotonin reuptake inhibitors (SSRis), bupropion, quinidine, cinacalcet, and ritonavir.
165
What is the most reliable method of pain assessment in children 4 years and older?
Self-report (faces pain scale in children younger than 7 and numerical rating scale in children 7 and older).
166
Why should codeine and hydrocodone be avoided in neonates and veryyoung children?
Their metabolism to morphinejhydromorphone depends on the cytochrome P450 2D6 (CYP2D6) enzyme, which is inactive at birth and only 25% active by age 5.
167
Which patients should avoid taking NSAIDs?
Those with a history of ischemic cardiac disease, stroke, congestive heart failure, and recent coronary artery bypass grafting.
168
True/False: Unless contraindicated, all surgery patients should routinely be given acetaminophen and an NSAID in scheduled doses throughout the early postoperative course.
True.
169
True/False: CYP2D6 has the largest phenotypic variability among the CYPs.
True.
170
What are the four levels of trichloroacetic acid (TCA) peels?
* Level o-No frost, skin appears slick and shiny representing removal of the stratum corneum.
* Level1-Irregular light frost with some erythema; 2-4 days of light peeling.
* Level 2-Pink white frost, full-thickness epidermal peel, 5 days of peeling.
* Level 3-Solid white frost, papillary dermis.
171
What skin preparations have been shown to significantly improve the overall severity of photodamaging but have not been shown to affect wrinkles?
8-10% a-hydroxy acids.
172
What is ochronosis?
A potential adverse reaction to hydroquinone characterized by a reticulated, sooty pigmentation of the cheeks, forehead, and periorbital regions.
173
What is an antisense drug?
A small, single-stranded nucleotide complementary to a target mRNA molecule that binds to mRNA and halts transcription.
174
Which drugs potentiate the effect of botulinum toxin?
Aminoglycoside antibiotics.
175
Which bleaching agent is also an effective treatment for acne?
Azelaic acid.
176
What is the mechanism of action of hydroquinone?
Blocks the conversion of dopa to melanin.
177
What is the mechanism of action of retinoids?
Cause a 70% inhibition of AP-1 transcription factor binding to DNA, which decreases the activation of metalloproteases such as collagenase, gelatinase, and stromatolysis.
178
What are lathyrogenic agents?
Compounds that inhibit collagen cross-linking, such as penicillamine and N-acetyl-L-cysteine.
179
What are the clinical effects of tretinoin?
Decrease in fine wrinkling, roughness, and mottled hyperpigmentation after 6 months of use.
180
How deep can a 20% trichloroacetic acid (TCA) solution penetrate?
Down to the papillary dermis.
181
How many serotypes of botulinum toxin exist? Which is the most useful clinically?
Eight serotypes (A through G) with type A being the most useful.
182
True/False: Large doses of vitamin E enhance wound healing.
False.
183
What medication used to treat androgenetic alopecia can reduce libido?
Finasteride.
184
What factors are thought to account for diminished responses to botulinum toxin?
Formation of antibodies, high cumulative dose, and drug interactions.
185
Which drugs limit the effect of botulinum toxin?
Guanidine and aminopyridines.
186
What are the initial manifestations of systemic phenol toxicity from a chemical facial peel?
Hyperreflexia and hypertension.
187
What effects do a-hydroxy acids have on the dermis?
Increase collagen and glycosaminoglycan production.
188
What would be the histologic findings on muscle biopsies at the site of botulinum toxin injections?
Increased unmyelinated axonal sprouts; no change in muscle fibers histologically.
189
What is the mechanism of action of botulinum toxin?
Inhibition of acetylcholine release from cholinergic nerve endings.
190
Which bleaching agent is produced by Aspergillus and Penicillium?
Kojic acid.
191
What medication used to treat androgenetic alopecia is also used to treat hypertension?
Minoxidil.
192
What are the onset, peak, and duration of effects of botulinum toxin?
Onset 24-72 hours, peak effect at 10-14 days, duration 3-6 months.
193
Which patients are better served by 15-20% a-hydroxy acids?
Patients with sebaceous, Fitzpatrick type III and IV skin.
194
How deep does Jessner's solution penetrate?
Remains intraepidermal.
195
What are the components of Jessner's solution?
Resorcinol, salicylic acid, lactic acid, and ethanol.
196
What is mitomycin C?
Substance produced by Streptomyces caespitosus that inhibits DNA synthesis and fibroblast proliferation.
197
What are the histologic effects of tretinoin?
Thinner stratum corneum, thickened epidermis, increased collagen, angiogenesis, and more uniform dispersion of melanin granules.
198
What is the purpose of application of topical vitamin C after skin resurfacing?
To decrease the inflammation associated with prolonged erythema (must wait until reepithelization is complete before applying).
199
True/False: Exogenous use of TGF-P appears to improve healing in tissues injured by radiation therapy.
True.
200
How is recovery of function accomplished?
Via sprouting of new nerve terminals and an increase in the number of postjunctional receptors.
201
When are cardiac arrhythmias that develop during a phenol peel most likely to occur?
Within 30 minutes of the start of the procedure.
202
'What are the criteria for bone densitometry in patients on long-term corticosteroids?
\> 5 mg/day for 3 or more months.
203
What is the treatment for Familial Ataxia Syndrome (Episodic Ataxia)?
Acetazolamide.
204
What is montelukast?
An antileukotriene, believed to stabilize rhinosinusitis in patients with Samter's triad.
205
What is the mechanism of action of steroids in the treatment of hemangiomas?
Block the estradiol-17 receptor.
206
In the United States, how are topical corticosteroids classified?
By their ability to constrict capillaries: Class I agents are the strongest and Class VII agents are the weakest.
207
What is the only nonsedating antihistamine that is eliminated primarily through the kidneys?
Cetirizine.
208
What effect does daily use of fluticasone have on nasal mucous?
Decreases the number of eosinophils in the mucous.
209
How do corticosteroids diminish lgE hypersensitivity reactions?
Diminish capillary permeability, block migratory inhibiting factor, stabilize lysosomal membranes, and inhibit edema formation.
210
True/False: Prolonged use of high-dose nasal steroids has been found to cause ocular hypertension.
False: This association was found with high-dose orally inhaled steroids only.
211
What is the recommended treatment for autoimmune inner ear disease?
First-line treatment is high-dose prednisone, then methotrexate, then cyclophosphamide.
212
What is the mechanism of action of meclizine?
H1-receptor antagonist.
213
What is the drug class of choice for mild esophagitis?
H2-receptor antagonists.
214
Why should patients on long-term PPI therapy be tested for Helicobacter pylori?
Hagiwara et al. found that long-term PPI administration promotes gastric adenocarcinoma in gerbils infected with H. pylori.
215
What is the mechanism of action of nasal cromolyn sodium?
Inhibits degranulation of mast cells.
216
'What is the most effective monotherapy for allergic rhinitis?
Intranasal corticosteroids.
217
Which causes less dry mouth: meclizine or scopolamine?
Meclizine.
218
What are the metabolic effects of prolonged thiazide diuretic therapy?
Metabolic alkalosis with hypokalemia and hypochloremia, hyperglycemia.
219
What drug used for gastroesophageal reflux disease (GERD) may cause irreversible tardive dyskinesia and is associated with dystonic reactions in 25% of young adults (18-30 years) who take it?
Metoclopramide.
220
What effect does oxymetazoline have on the nasal cilia?
Paralyzes them.
221
Which drug class used for the treatment of GERD is associated with an increased risk of hip fracture in postmenopausal women?
Proton pump inhibitors (PPis).
222
What symptom do intranasal anticholinergics treat?
Rhinorrhea.
223
Why is ticlid only warranted in patients unable to tolerate aspirin?
Risk of life-threatening neutropenia.
224
What is the mechanism of action of ondansetron and dolasetron?
Selective antagonists of serotonins-HT3 receptors with no effect on dopamine receptors.
225
What is the primary reason periodic breaks should be taken when using topical corticosteroids for chronic conditions?
To prevent tachyphylaxis.
