Pharmacology Exam Practice Questions - 6, Part 5

dermregperth's version from 2017-05-21 09:32

66. Regarding topical agents

Question Answer
Regarding topical agents: Aluminium chloride can be mixed with ethyl alcoholTrue (p631)
Regarding topical agents: Aluminium chloride has thrombotic propertiesTrue (p631)
Regarding topical agents: Monsel’s solution stains the skinTrue (The advantage of aluminum chloride over Monsel’s solution is that it does not leave an iron residue that can persist in the dermis, essentially creating a tattoo) (Q55-3, p631)
Regarding topical agents: Silver nitrate has antimicrobial propertiesTrue (Table 55-3, p631)

67. Itraconazole

Question Answer
Itraconazole: Should be avoid in those with severe heart diseaseTrue (Q9-11, p109)
Itraconazole: Metabolised by CYP3A4True (Table 9-2, p100)
Itraconazole: Persists in stratum corneum for 3-4 weeksTrue (p101)
Itraconazole: Detected in fingernail in 1 week of startingTrue (detectable in the sweat within 24 hours, hair after 1 week, fingernails in 1 week & toenails in 2 weeks) (p100-102)
Itraconazole: Selectively works on the hair follicleFalse It can be delivered to the hair by two routes 1 via the sebum and 2 via incorporation into the hair follicle
Itraconazole: Detected in the hair in 24 hours of startingFalse (detectable in the sweat within 24 hours, hair after 1 week, fingernails in 1 week & toenails in 2 weeks) (p100-102)

68. Doxepin

Question Answer
Doxepin: Lowers the seizure thresholdTrue (Doxepin should also be used with caution in patients with a history of seizure disorder or manic–depressive disorder, because it can lower the seizure threshold and precipitate a manic episode) (p380)
Doxepin: Prolongs QT intervalTrue (Thus, older patients or any patient with a history of cardiac conduction disturbance should have a pretreatment electrocardiogram (ECG) to rule out the presence of prolonged QT interval. In addition, an ECG should be repeated to rule out dysrhythmia if doxepin is used in dosages of 100 mg daily or higher)(Q31-5, p380)
Doxepin: Works on H1 and H2True (Q28-4, p351)
Doxepin: 5% cream causes drowsinessTrue (p351)
Doxepin: Can be given with other antidepressantsFalse (p351)
Doxepin: Can be given with heart diseaseFalse (Should not be administered in the presence of severe heart disease)(p351)

69. Nicotinamide

Question Answer
Nicotinamide: Is well absorbed after an oral doseTrue (p432)
Nicotinamide: Is renally excreted?True
Nicotinamide: Can cause flushing side effectsFalse (p433) ? correct answer. Whereas nicotinic acid is a potent vasodilator, nicotinamide is not, and thus is not typically associated with flushing and other prostaglandin-triggered side effects. According to derm net NZ it does not cause flushing.

70. Regarding tetracyclines

Question Answer
Regarding tetracyclines: Are safe in children under 9False (TCN should be avoided (apart from life-threatening infections) in children <9 years of age owing to yellow staining of teeth, and possibly other adverse effects on the development of bones and teeth) (p85)
Regarding tetracyclines: Pseudomotor cerebri can occur only with oral retinoidsFalse (TCNs and oral retinoids have both been independently associated with BIH, concern regarding an additive or synergistic effect has been noted) (p85)

71. Bactrim

Question Answer
Bactrim: Sulfamethoxazole is a dihydropteroate synthetase inhibitorTrue (Trimethoprim-Sulfamethoxazole combines a dihydrofolate reductase inhibitor (trimethoprim, TMP) and a dihydropteroate synthetase inhibitor (sulfamethoxazole, SMX)) (Q8-12, p92)

72. Bactroban (Mupirocin)

Question Answer
Bactroban: Erythromycin is more expensive that BactrobanFalse (p450).
Bactroban: Can be used on open woundsTrue (However, Mupirocin may be less effective on weeping wounds because 95% of the drug is protein bound) (p449-450).
Bactroban: Is effective in MRSA TreatmentTrue (p449)

73. Griseofulvin (Chapter 9)

Question Answer
Griseofulvin: Is active against T.tonsuransTrue
Griseofulvin: Absorption is enhanced when taken with a fatty mealTrue
Griseofulvin: Interferes with the OCPTrue
Griseofulvin: Activity against Malassezia furfurFalse (Malassezia yeasts are associated with Tinea versicolor. Griseofulvin & Terbinafine are not effective for Tinea Versicolor) (Q9-7, p107)
Griseofulvin: Men need to avoid fathering children for 6 months after cessationTrue

74. Penicillins

Question Answer
Penicillins: Penicillin V is safe in pregnancyTrue (Cat B) (p62)
Penicillins: Aminopenicillins have higher rate of allergic reactionsTrue (Q8-3, p64)
Penicillins: Clavulanate is a beta lactamase inhibitorTrue (p68)

75. Dapsone

Question Answer
Dapsone: Is well absorbed from gutTrue (Gut absorption is 70-80%) (p228)
Dapsone: Is lipid solubleTrue (lipid soluble, is water insoluble) (p228)
Dapsone: Half-life is 10-30 hoursFalse (Half-life averages between 24-36 hours; with significant individual variability ranging from 10-50 hours) (p228)
Dapsone: Is a H2 blockerFalse (H2 antacids decrease serum levels of Dapsone due to decreased GI absorption, but Dapsone is not an antihistamine. Doxepin however is) (p238)

76. Cyclophosphamide

Question Answer
Cyclophosphamide: Is associated with bladder cancerTrue (p222)
Cyclophosphamide: Is associated with acute non-lymphocytic leukemia (acute myeologenous leukaemia)True (p706)
Cyclophosphamide: Is associated hemorrhagic cystitisTrue (Q62-8, p706)
Cyclophosphamide: Is associated with B cell suppression more than T cell suppressionTrue (Cyclophosphamide has a greater effect upon B lymphocytes than T lymphocytes, and a greater effect upon suppressor T cells than helper T cells) (Q17-9, p219)

77. Methotrexate

Question Answer
Methotrexate: Probenacid reduces renal excretion of MTXTrue (Table 13-1, p171) also see table 65-2 on pg 733
Methotrexate: NSAID reduces renal excretion of MTXTrue (Table 13-1, p171) also see table 65-2 on pg 733
Methotrexate: Dapsone reduces renal excretion of MTXFalse (Inhibits folate metabolic pathway --> increase hematologic toxicity by but not by decreased renal excretion) (Table 13-1, p171)
Methotrexate: Penicillin reduces renal excretion of MTXTrue see table 65-2 on pg 733
Methotrexate: Hepatotoxicity is the greatest concerning potential riskFalse (Hematologic toxicity, such as pancytopenia, presents the greatest potential for loss of life due to MTX. By far the greatest amount of literature on MTX exists in patients on it for rheumatology conditions.) pg 176

78. Pimecrolimus

Question Answer
Pimecrolimus: Has the same mechanism of action as TacrolimusTrue (Q44-1, p539)
Pimecrolimus: Should not be used in infantsTrue (It is a relative contraindication in children < 2 years) (Box 44-2, p540)
Pimecrolimus: Binds to the FK506-binding protein leading to inhibition of CalcineurinTrue (p539)
Pimecrolimus: Topical Pimecrolimus increases the risk of malignancyFalse (Q44-7, p542)
Pimecrolimis: Is effective in the treatment of alopecia areata & acne vulgarisFalse (p541)

79. In regards to the following drugs, does concomitant dosing increase the risk of toxicity

Question Answer
Drug Interactions: Concomitant dosing of Allopurinol & Cyclophosphamide increases toxicityTrue (Increases Cyclophosphamide levels by decreasing it’s metabolism) (Box 17-9, p223)
Drug Interactions: Concomitant dosing of Doxycycline & Mycophenolate mofetil increases toxicityFalse ? not in the table Macrolides are mentioned and may decrease serum levels of MPA because of reduced enterohepatic recirculation (Table 15-2, p196)
Drug Interactions: Concomitant dosing of Dapsone & Fluconazole increases toxicityTrue (Azole antifungals competitively inhibit CYP3A4, increasing Dapsone. Includes Ketaconazole, Itraconazole & Voriconazole) (Table 65-2, p733)
Drug Interactions: Concomitant dosing of NSAID & Methotrexate increases toxicityTrue (NSAID cause displacement of MTX from plasma proteins) (Table 65-2, p733)
Drug Interactions: Concomitant dosing of Methotrexate & Sulphonamides increases toxicityTrue (Sulphonamides cause displacement of MTX from plasma proteins) (Table 65-2, p733)
Drug Interactions: Concomitant dosing of Penicillin & Methotrexate increases toxicityTrue (Penicillins cause reduced renal elimination of MTX) (Table 65-2, p733)
Drug Interactions: Concomitant dosing of Retinoids & Tetracyclines increases toxicityTrue (Tetracyclines increase Retinoid toxicity via synergy) (Table 65-2, p733)
Drug Interactions: Concomitant dosing of Warfarin & Cholestyramine increases toxicityFalse (Cholestyramine interferes with enteroheptic reciculation, and subsequently reduces the half life of Warfarin) (p733)
Drug Interactions: Concomitant dosing of Griseofulvin & oral contraceptives increases toxicityFalse (Griseofulvin induces CYP3A4, decreasing efficacy of OCPs) (p735)
Drug Interactions: Concomitant dosing of Dexamethasone & Warfarin reduces Warfarin efficacyTrue (Dexamethasone induces CYP3A4, decreasing efficacy of Warfarin) (p735)
Drug Interactions: Concomitant dosing of Digoxin & Ketaconazole increases toxicityTrue (Itraconazole & Ketaconazole increase Digoxin toxicity through inhibition of p-glycoprotein) (p734)

80. Aspirin

Question Answer
Aspirin: High dose Aspirin inhibits the aggregation & activation of platelets, inflammation & feverFalse (Low dose does this: 81-325mg) (p357)
Aspirin: Peak plasma levels are reached after 2 hoursTrue (p357)
Aspirin: The protein bound portion is the active componentFalse (Only the free drug is active) (p357)
Aspirin: Urinary excretion of Aspirin is dependent on pHTrue (Excretion is greater in alkaline urine)
Aspirin: Peptic ulcer disease & GI bleeding are complications only at high dosesFalse (Even at lower doses) (p357)