Pharmacology Exam Practice Questions - 5, Part 5

dermregperth's version from 2017-05-21 09:22



84. Colchicine:
Question Answer
Colchicine: Is it an anti-mitotic and anti-inflammatoryTrue is thought to be antimitotic and and anti-inflammatory pg 429
Colchicine: Indicated for use in Behcet's diseaseTrue. Many other indications including aphthous stomatitis, pachydermoperiostosis pg 428 table 35-1
Colchicine: Question about mechanism of actionColchicine concentrates in leukocytes. It binds to dimers of tubulin, preventing their assembly into microtubules. This results in mitotic arrest at metaphase and interference with cell motility and chemotaxis.
Colchicine: Gastrointestinal side effects manifest firstTrue Gastrointestinal. Chronic intoxication usually leads to haematological issues such as leukopenia and aplastic anaemia. Pg 430
Colchicine: Watery diarrhoea is a common side effectTrue commonly occur.


85. Antihistamines:
Question Answer
Regarding antihistamines: Cetirizine - causes drowsiness True. It is considered the most sedating of the second-generation H1 antihistamines and caution is recommended with doses over 10mg daily.
Regarding antihistamines: Loratadine - resistance can be inducedFalse. Tolerance to repeated doses dose not appear to be a problem pg 349
Regarding antihistamines: Fexofenadine - may prolong QT intervalFalse. Co-administration of fexofenadine with macrolide antibiotics and imidazole antifungal failed to reveal evidence of interactions, with no Q-T prolongation . Terfenadine was the drug that caused this pg 348.
Regarding antihistamines: Fexofenadine is metabolised by the liverFalse. Is not metabolised by the liver and is excreted essentially unchanged in the faeces. Pg 348


86. Antibiotics:
Question Answer
Topical erythromycin: Has 25% resistance in the communityTrue. 25% of antibiotic-treated patients in the community harboured erythromycin-resistant strains P.acnes
Clindamycin: Adverse event of c. difficile colitis in 20% of treated patientsFalse. Too high. Usually in 0.1-10% of clindamycin-treated patients.


87. PUVA:
Question Answer
PUVA: Increased risk of melanoma above 250 treatmentsTrue above 250 treatments pg 286
PUVA: Associated with increased risk of BCCTrue. In patients who receive high cumulative UVA exposure. Usually risk increased over 250 treatments.
PUVA: SCC associated with PUVA are not more biologically aggressiveTrue. There are no difference between the two. Pg 285
PUVA: Increased risk of NMSCs with patients receiving more than 250 treatments of PUVATrue pg 285
PUVA: Increased risk of melanomas with patients receiving more than 100 sessionsFalse usually over 250 treatment for increase melanoma risk pg 285


88. Salicylism question copied from 2016 paper:
Question Answer
Salicylism: Starts after 3 daysFalse (Topical application of Salicylic acid, with concentrations as low as 3%, applied 3 times daily for 5 days to the entire skin below the neck in an adult, resulted in toxicity. Signs of salicylate toxicity generally occur when blood concentrations exceed 35mg/dl.) (p598)
Salicylism: Children prone to acidosisTrue (With salicylate toxicity there is stimulation of the medullary respiratory centre that causes marked hyperventilation & respiratory alkalosis; in infants & children, metabolic acidosis may also occur)
Salicylism: Causes psychosisTrue (Systemic toxicity includes GI, neurologic, metabolic & miscellaneous side effects (tinnitus & hyperventilation). Neurologic SFX include: Confusion, Dizziness, Delirium, Psychosis, Stupor, Coma, Death) (p598)
Salicylism: Occurs at 20mg/dlFalse (Signs of salicylate toxicity generally occur when blood concentrations exceed 35mg/dl.) (p598)
Salicylism: Causes neuropathyFalse (Neurologic side effects are confusion, dizziness, delirium, psychosis, stupor, coma & death) (p598)