NMS Q&A Family Medicine

328 NMS Q&A Family MedicineExamination Answers1. The answer is C. Sulfonamides is the group or drugmentioned that is not included among those that mayprecipitate a pityriasis-like rash. Other agents that may doso besides those mentioned (captopril, barbiturates, metronidazole,and metoprolol) include bismuth, clonidine,gold salts, methopromazine, and tripelennamine.2. The answer is D. Ethinyl estradiol is not metabolizedin the 2D6 system. Lamisil (terbutaline) inhibits 2D6metabolism, and the other drugs presented in the vignetteare metabolized in that system; hence, their dosages mightneed to be lowered due to their enhanced metabolismwhen terbutaline is administered at the same time. Inaddition to tricyclics, beta-blockers, SSRIs, and class Cantidysrhythmics (e.g., flecainide and propafenone),other CYP 450 2D6 metabolized drugs that would fallunder this alert include monoamine oxidase inhibitors(MAOIs).3. The answer is A. Acetazolamide increases renal excretion,thus reducing the chance of lithium toxicity. Allother diuretics, that is, thiazides and loop diuretics likefurosemide, as well as any clinical dehydration states andconditions that result in dehydration including diarrheaand vomiting enhance the tendency to reduce serumsodium manifesting lithium toxicity. ACEIs increase therisk of lithium intoxication. Carbamazepine enhances therisk of neurotoxicity of lithium. Metronidazole may provokelithium toxicity due to reduced renal clearance as dourea, xanthines, and alkalinizing agents. Lithium toxicityencompasses a large spectrum of physiological systemsincluding cardiovascular (e.g., dysrhythmias), gastrointestinal,dermatologic (including alopecia, anesthesia,acne, xerosis cutis, and psoriasis).4. The answer is D. Thioridazine has been reported toworsen the tremor of Parkinson disease when given alongwith amantadine (Symmetrel). It is not known whetherother phenothiazines have the same effect. Hydrochlorothiazide/triampterene(Dyazide, Maxzide) has beenshown to increase the blood level of amantadine when thetwo are taken during the same period. Amitriptyline(Elavil), trihexyphenidyl (Artane), and benztropine(Cogentin) each potentiates the anticholinergic effects ofamantadine.5. The answer is D. The serum creatinine level must bechecked before metformin is started. Lactic acidosis, albeitrare, has been reported with the usage of metformin in thepresence of renal failure. The pharmaceutical guidelinesstate that metformin should not be prescribed if the serumcreatinine level is above 1.5 mg/dL in male patients or 1.4 infemale patients. Metformin should be held for 48 hoursbefore general anesthesia. The foregoing is emphasizedmore in diabetics, the very group for whom it is prescribed.6. The answer is C. Pregnancy in the second or thirdtrimester is a firm contraindication for ACEIs and forangiotensin-converting enzyme receptor blocking agents(e.g., valsartan). These drugs may cause fetal injury ordeath. Although dry cough may be a side effect of ACEIs(not angiotensin-converting enzyme receptor blockingagents) and this may be a subclinical expression of asthmaor reactive airway disease, a history of these conditions isnot a contraindication to the use of ACEIs.7. The answer is D. Discontinue clonidine and wait2 days before starting atenolol at a prudent beginningdosage. Beta-blockers may exacerbate rebound hypertensionfollowing discontinuance of clonidine. Thus, if thebeta-blocking agent is present when discontinuance ofclonidine is contemplated, then the beta-blocker shouldbe stopped 2 days before the clonidine. If the beta-blockeris to replace clonidine, then it should wait for 2 days afterdiscontinuance of clonidine before being started.8. The answer is E. Glaucoma as a complication of prolongedusage of glucocorticoids is perhaps not appreciated;it is less well known than side effects such asprecipitation of diabetes, elevation of blood pressure,Cushing syndrome, aggravation of certain viral infections(varicella, herpes zoster keratitis), and osteoporosis. Theother choices have no relationship to glucocorticoids andare true distracters.9. The answer is C. Flumazenil is a benzodiazepine receptorblocker and is specific for overdose of this family ofdrugs. Naloxone and buprenorphine are virtually completeand partial opioid antagonists respectively. Phenobarbital,one of the most ancient sedatives, would, ofcourse, aggravate the sedative effects of the benzodiazepine.Dextroamphetamine, although a sympathomimeticmedication, is not employed in sedative overdosemanagement. However, dextroamphetamine inhibits gastrointestinalabsorption of the sedative phenobarbital.10. The answer is D. Dry mouth. Fluoxetine (Prozac),being CYP2D6 system metabolized, increases blood levelof tolterodine, an anticholinergic antispasmodic and assuch would be expected, even normally to result in a highpercentage of incidence of dry mouth. This would becompounded and enhanced by any drug that increases its