Pharmacology Exam Practice Questions - 5, Part 3

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



38. Regarding tetracycline
Question Answer
Regarding tetracyclines: A lupus-like syndrome is unique to minomycinTrue does not occur is other tetracyclines and is unique to minocycline pg 84. Can also occur in some Anti-TNF inhibitors pg 752.
Regarding tetracyclines: Doxycycline may cause photo-onycholysisTrue. Most reports are due to doxycline pg 83.
Regarding tetracyclines: Tetracyclines are excreted by the biliary tract primarilyFalse. Most are renally excreted except doxycline which is primarily excreted by the GI tract in bile and thus is acceptable for use in patients with renal failure.
Regarding tetracyclines: Tetracyclines may cause the side effect of pseudotumor cerebriTrue. However, it is an uncommon idiopathic reaction to TCNs.


39. Methotrexate:
Question Answer
Methotrexate: MTX is also known as amethopterinTrue. Pg 169.
Methotrexate: Severe renal dysfunction increases risk of adverse effectsTrue. Including pancytopenia and other MTX toxicities. Pg 177
Methotrexate: MTX is a weak alkaliFalse. Weak organic acid pg 170.
Methotrexate: Commonly causes macrocytosis without anaemiaTrue (Macrocytic indices without anemia are common with dermatologic dosage levels of MTX.) (p176)
Methotrexate: Undergoes biphasic eliminationFalse. MTX has triphasic reduction.
Methotrexate: Metabolised to polyglutamated forms intracellularlyTrue. Pg 170. Evidence suggests that drug is metabolised intracellularly, including by the liver, to polyglutamated forms.


40. Methotrexate drug interactions drug reduce renal excretion: pg 733 and 171
Question Answer
Regarding MTX combined with drug reduces renal excretion: ProbenecidTrue (All of these reduce renal elimination of MTX: NSAIDs, Penicillins, Probenecid, Salicylates, Sulphonamides) (p733)
Regarding MTX combined with drug reduces renal excretion: NSAIDTrue (All of these reduce renal elimination of MTX: NSAIDs, Penicillins, Probenecid, Salicylates, Sulphonamides) (p733)
Regarding MTX combined with drug reduces renal excretion: DapsoneFalse. Inhibits dihydropteroate synthetase and cause increase haematological toxicity pg 171
Regarding MTX combined with drug reduces renal excretion: AllopurinolFalse. Reduced metabolic clearance pg 733
Regarding MTX combined with drug reduces renal excretion: PenicillinTrue (All of these reduce renal elimination of MTX: NSAIDs, Penicillins, Probenecid, Salicylates, Sulphonamides) (p733)


41. Calcineurin inhibitors
Question Answer
Calcineurin inhibitors: Works by reducing the activity of the nuclear factor of activated T cells (NFAT-1)True. This complex (FK506-binding protein) binds to calcineurin, blocking its ability to dephosphorylate
Calcineurin inhibitors: Topical calcineurin inhibitors have low molecular weightsTrue Cyclosporine has a large molecular weight (1230 Da) results in poor epidermal penetration. In contrast tacro/pimecrolimus have lower molecular weights (804/809)Pg 535
Calcineurin inhibitors: This reduce production of IL-2True. Prevents transcription of the cytokine IL-2, blocks T-cell activation and proliferation and further cytokine production.


42. Cyclosporine:
Question Answer
Cyclosporine: Microsizing improves absorptionTrue. Neoral, a more bioavailable and more consistently absorbed microemulsion formulation of CsA. pg 199
Cyclosporine: Administration with grapefruit juice improves absorptionFalse. Grapefruit juice affects the metabolism of CsA and should be avoided. Orange and apple juice CAN be used. Pg 199
Cyclosporine: Dosage should be adjusted in renal failure?True. Dose adjustments are recommended when changes from baseline creatinine are between 25-50%. But… neither dialysis or renal failure significantly alter the drug’s clearance. Pg 204 and 203
Cyclosporine: It is a teratogenFalse. In contrast to other immunosuppressive drugs used for psoriasis is is not cytotoxic, does not supress bone marrow and is not teratogenic. Pg 199
Cyclosporine: Is excreted in breast milkTrue. Is excreted in human breast milk and so breastfeeding should be avoided. Pg 200


43. Systemic retinoids:
Question Answer
Systemic retinoids: DISH occurs only with high doses of 1-3mg/kgTrue. Usually for 5 years Pg 263.
Systemic retinoids: Low dose to treat acne can cause premature epiphyseal closureFalse. Has been reported with retinoid therapy but is rare occurring only with higher doses.
Systemic retinoids: Patients on isotretinoin should be informed about and monitored for depressionTrue but is controversial pg 262.


44. Antivirals:
Question Answer
Antivirals: Human interferon can cross the placental barrierFalse. It does not cross the placenta. Unknown for humans whether is crosses into breast milk, but mouse IFN does. Pg 270
Antivirals: Half life of interferon 21 daysFalse. Multiple types of IFN half life ranges from 2-8.5 hours. Pg 270 table 21-2.
Antivirals: Pegylation prolongs time for interferon to remain in circulationTrue. Polyethylene glycol is attached to the interferon to increase time in circulation and reduce frequency of dosing. Pg 270
Antivirals: Interferon undergoes renal catabolismTrue undergo renal catabolism and rapid proteolytic degradation during tubular reabsorption with only minor hepatic metabolism. Pg 270.
Antivirals: Neutralising antibodies to interferon reduces efficacyTrue. Pg 270.


45. Topical Vitamin D3:
Question Answer
Topical Vitamin D3: Provitamin D3 (7-dehydrocholesterol) is activated by UVB lightTrue provitamin D3 (7-dehydrocholesterol) is cleaved by UVB light to form previtamin D3 (9, 10 secosterol precholecalciferol)
Topical Vitamin D3: It undergoes hydroxylation in the liverTrue. Vitamin D3 is transported to the liver, where is undergoes hydroxylation by the CYP450 enzyme 25-hydroxylase to become 25-hydroxyvitamin D3.
Topical Vitamin D3: It can undergo pulmonary alveolar metabolism for hydroxylationTrue. In the kidney (as well as in other tissues such as placenta, pulmonary alveolar macrophages and bones cells) 25-hydroxyvitamin D3 is hydroxylated again to form calcitriol (1,25 D3) the active hormone pg 543
Topical Vitamin D3: Keratinocytes have all of the enzymes required to hydroxylate vit D to the active calcitriolTrue. They contain all of the necessary enzymes to covert 7-dehydrocholesterol to active calcitriol.
Topical Vitamin D3: Isomerisation is affected by temperatureTrue Temperature-dependent isomerisation of previtamin D3 occurs, generating vitamin D3 in the skin. Pg 543


46. Antimalarials:
Question Answer
Antimalarials: Half life of hydroxychloroquine is about 50 daysTrue pg 242
Antimalarials: 20% of HCQ is excreted unchanged in urine True. 20% is excreted unchanged in the urine; also biliary excretion. Pg 242
Antimalarials: Does adjustment is always required in renal impairmentFalse. Not usually required. No dosage adjustment is necessary for patients with mild-moderate renal function impairment. Pg 242
Antimalarials: Halos around lights indicate retinopathyFalse. Indicate corneal deposits. Pg 246
Antimalarials: Retinopathy is irreversibleTrue. True retinopathy “bulls eye” pigment deposition, central scotoma, visual acuity changes. Pg 246 see table 19-2. But pre-maculopathy is reversible and is a type of retinopathy
Antimalarials: Hydroxychloroquine effects in 2 weeksFalse. Half life 40-50 days takes a long time to reach steady state 3-4 months may account for the slow appearance of therapeutic benefit. Pg 242.


47. More antimalarial questions:
Question Answer
Antimalarials: G6PD testing is required prior to hydroxychloroquineFalse. G6PD testing prior to antimalarial testing is somewhat controversial, probably more important with antimalarial agents rarely used in dermatology such as primaquine.
Antimalarials: Amsler grid testing is a good screening test for retinopathyFalse. The patient-administered Amsler-grid testing has not been established as a method of screening pg 246
Antimalarials: If known G6PD deficiency, dose reduction is NOT requiredTrue (Antimalarials may be used with caution and proper monitoring – for children, for patients with G6PD deficiency, and for psychotic patients. Testing for G6PD deficiency has not been deemed necessary for patients being treated with HCQ, CQ, or quinacrine because hemolysis is unlikely at recommended dosages. It is primarily with the 8-aminoquinoline antimalarials such as primaquine & amiodaquine that baseline G6PD testing is required.) (p246)
Antimalarials: Standard dose range 6.5mg/kg/dayFalse. This is the max dose of HCQ that is usually used. Pg 249.


48. Topical drugs including tar:
Question Answer
Regarding tar: Exerts effects only as a keratolyticFalse. It has conclusive antiproliferative effects on the epidermis and also has anti-inflammatory effects (shale/bituminous tar). Pg 600.
Regarding tar: May stain hair greenTrue. Can stain blonde, white/gray or dyed hair a greenish or brown colour.
Regarding tar: Coal tar distillation is at 1800 degrees CelsiusFalse tar distillation is between 900-1200 degrees Celsius. Pg 600.
Regarding tar: Icythyol is also known as shale oilTrue
Regarding tar: Wood tar preparations have more carcinogenic agentsFalse. Coal tar is more carcinogenic.
Regarding tar: Max compounded concentration of tar is 15%False maximum is 20% usually ranges from 5-20%


49. IVIG:
Question Answer
Regarding IVIG: Can cross the placentaTrue (It distributes through the intravascular (60%) & extravascular (40%) spaces, crosses the placenta, & may be excreted into milk. Pregnancy is not a contraindication) (p389, p391)
Regarding IVIG: Half life is about 4 weeksTrue. Is between 3-5/52 (p389)
Regarding IVIG: Patients with IgA deficiency have increased risk of anaphylaxisTrue see pg 391 table 32-1.
Regarding IVIG: Up to 30% of the dose may be removed by catabolism in 24 hoursTrue Up to 30% of the dose is removed by catabolism & distribution in the 1st 24 hrs (p389, p391)
Regarding IVIG: Is it excreted in breast milk True see pg 389.


50. Etanercept:
Question Answer
Etanercept: Is a fully human fusion proteinTrue. Fully human fusion protein pg 309.
Etanercept: Only binds to soluble TNF alpha False. Can also bind to TNF-B. pg 309. Inflixumab and adalimumab only bind to TNF-a
Etanercept: Has a half life of 3 daysFalse. Has a half life of 4.8 days. Pg 308
Etanercept: Bioavailability of 58%True. Inflixumab has bioavailability of 100% and adalimumab is 64%


51. Infliximab:
Question Answer
Infliximab: Is a chimeric IgG monoclonal antibodyTrue pg 312.
Infliximab: Infusion reaction in 1% of patients onlyFalse. Approximately 20% experienced infusion reactions. Less than 1% of patients with infusion reactions, experienced serious side effects. Pg 313
Infliximab: Anti-drug antibodies reduces efficacyTrue. Anti-drug antibodies correspond to an increased clearance of infliximab, increased incidence of infusion reactions and reduced efficacy. Pg 313
Infliximab: Half life 7-9 daysTrue. See table 25-2 on pg 308.
Infliximab: Bioavailability is 100%True. See table 25-2 on pg 308.


52. Adalimumab:
Question Answer
Adalimumab: Is a fully human IgG1 recombinant antibody True is a fully human IgG recombinant antibody to TNF-a only. Pg 314
Adalimumab: What are the absolute contraindications to adalimumabAbsolute contraindication are known hypersensitivity, concurrent Anakinra, Active/chronic infections including TB pg 314 table 25-3
Adalimumab: Is half life of adalimumab 14 daysTrue. See table 25-2 on pg 308.


53. Ustekinumab:
Question Answer
Ustekinumab: Is it a fully human monoclonal IgG1 antibody that acts on the p40 subunit of IL-12 and IL-23True fully human monoclonal antibody directed with high affinity and specificity against p40 subunit IL-12 and IL-23. Pg 319
Ustekinumab: Half life of 21 daysTrue Half life approximately 21.6 days in clinical trial for psoriasis. Pg 326. Dosing schedules are weeks 0 and 4, then every 12 (45mg or 90mg if >100kg).
Ustekinumab: Dosing is based on patients weightTrue. (Usually based around above and below 100kg. Dosing schedules are weeks 0 and 4, then every 12 (45mg or 90mg if >100kg)) p320 Table 26-1
Ustekinumab: Increases risk of multiple sclerosisFalse. It does not create any neurological events. In contrast to TNF inhibitors which have been associated with new onset or exacerbation of CNS demyelinating disorders. Pg 329.
Ustekinumab: Significant effects in as early as 2 weeksTrue. Moderate to severe plaque psoriasis and noted improvement in psoriasis signs and symptoms as well as significant improvement in QOL scores as early as 2 weeks into therapy.


54. Rituximab:
Question Answer
Rituximab: Is it a depleting antibody against B-cell surface antigen CD20True. It depletes CD-20 B-cell surface antigen. Pg 333
Rituximab: Is it metabolised by phagocytosisTrue. p333
Rituximab: Half life is 24 hoursFalse. Its half life is about 21 days in circulation.
Rituximab: Is it a chimeric murine-human antibodyTrue pg 333.


55. Terbinafine:
Question Answer
Terbinafine: Side effects include vasculitisTrue. SE common: taste/visual disturbance/nasopharyngitis/nasal congestions. Uncommon: depressive, vasculitis, angioedema, neutropenia, thrombocytopenia.
Terbinafine: Can terbinafine cause taste disturbancesTrue. Pg 112 table 9-7.
Terbinafine: Depression is a side effectTrue. Pg 112 table 9-7.


56. Epidermal growth factor receptor inhibitors:
Question Answer
Regarding ERGF inhibitors: Papulopustular eruption is a common side effect which can affect up to 90% of patientsTrue. Pg 401
Regarding ERGF inhibitors: The eruption is usually in a photosensitive distributionFalse. In areas rich in sebaceous glands. Pg 401
Regarding ERGF inhibitors: This rash typically occurs after 2-3 months False. Peaks in 2-3 weeks. Pg 401
Regarding ERGF inhibitors: The presence and severity of this papulopustular eruption has a positive correlation with tumour response with cetuximabTrue pg 401.
Regarding ERGF inhibitors: EGFR inhibitors are used in the treatment of cutaneous SCCsTrue. Have been used for advanced or metastatic cutaneous SCC. Pg 397.


57. Side effects:
Question Answer
Drug SE: Does azathioprine have potential hepatocellular complicationsTrue see table 60-7 on pg 683
Drug SE: Can acitretin cause cholestasisFalse. It causes steatosis. see table 60-7 on pg 683
Drug SE: Does cyclophosphamide have veno-occlusive side effectsTrue. Mainly high dose. See table 60-8 on 684.