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Discussion Starter · #1 ·
A 55-year-old has episodes of intense pain in his eyes, lips, scalp and jaw. The pain is described as a "stabbing, "electric-shock" sensation. Consultation with a dentist reveals that the pain is not of dental origin. You suspect that the pain syndrome involves one of the cranial nerves and prescribe the first line medication for this condition. Which of the following is not a side effect associated with this medication?
A. Ataxia
B. Diplopia
C. Agranulocytosis
D. Inhibition of cytochrome p450
E. Aplastic anemia
 

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Good question

Yup - Carbamazepine is an important inducer not an inhibitor of the p450 system used to treat trigeminal neuralgia - as everyone has said. This question is really good because of it's multi step multi discipline approach - the kind of thing that makes you feel smart when you get it :)

Here's First Aid's list of inducers and inhibitors... without making CYP450 isoform distinctions - anything run into a "which isoform question on the step ever, btw?"

Inducers: Quinidine, Barbiturates, St. John's wort, Phenytoin, Rifampin, Griseofulvin, Carbamezapine, Chronic alcohol

Mnemonic: Queen barb steals Phen-phen and Refuses Greasy Carbs Chronically

Inhibitors: Sulfonamides, Isoniazid, Cimetidine, Ketoconazole, Erythromycin, Grapefruit juice, Acute Alcohol use

Mnemonic: KEG = Acutely SICk
 

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Discussion Starter · #7 ·
yep guys the answer is D:)
 
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