Clinically Relevant Drug-Drug Interactions in Primary Care.

Drug interactions are common in the primary care setting and are usually predictable. Identifying the most important and clinically relevant drug interactions in primary care is essential to patient safety. Strategies for reducing the risk of drug-drug interactions include minimizing the number of drugs prescribed, re-evaluating therapy on a regular basis, considering nonpharmacologic options, monitoring for signs and symptoms of toxicity or effectiveness, adjusting dosages of medications when indicated, and adjusting administration times. Inhibition or induction of cytochrome P450 drug metabolizing isoenzymes is the most common mechanism by which clinically important drug interactions occur. The antimicrobials most likely to affect the international normalized ratio significantly in patients receiving warfarin are trimethoprim/sulfamethoxazole, metronidazole, and fluconazole. An empiric warfarin dosage reduction of 30% to 50% upon initiation of amiodarone therapy is recommended. In patients receiving amiodarone, limit dosages of simvastatin to 20 mg per day and lovastatin to 40 mg per day. Beta blockers should be tapered and discontinued several days before clonidine withdrawal to reduce the risk of rebound hypertension. Spironolactone dosages should be limited to 25 mg daily when coadministered with potassium supplements. Avoid prescribing opioid cough medicines for patients receiving benzodiazepines or other central nervous system depressants, including alcohol. Physicians should consider consultation with a clinical pharmacist when clinical circumstances require the use of drugs with interaction potential.

Vision Loss in Older Adults.

Vision loss affects 37 million Americans older than 50 years and one in four who are older than 80 years. The U.S. Preventive Services Task Force concludes that current evidence is insufficient to assess the balance of benefits and harms of screening for impaired visual acuity in adults older than 65 years. However, family physicians play a critical role in identifying persons who are at risk of vision loss, counseling patients, and referring patients for disease-specific treatment. The conditions that cause most cases of vision loss in older patients are age-related macular degeneration, glaucoma, ocular complications of diabetes mellitus, and age-related cataracts. Vitamin supplements can delay the progression of age-related macular degeneration. Intravitreal injection of a vascular endothelial growth factor inhibitor can preserve vision in the neovascular form of macular degeneration. Medicated eye drops reduce intraocular pressure and can delay the progression of vision loss in patients with glaucoma, but adherence to treatment is poor. Laser trabeculoplasty also lowers intraocular pressure and preserves vision in patients with primary open-angle glaucoma, but long-term studies are needed to identify who is most likely to benefit from surgery. Tight glycemic control in adults with diabetes slows the progression of diabetic retinopathy, but must be balanced against the risks of hypoglycemia and death in older adults. Fenofibrate also slows progression of diabetic retinopathy. Panretinal photocoagulation is the mainstay of treatment for diabetic retinopathy, whereas vascular endothelial growth factor inhibitors slow vision loss resulting from diabetic macular edema. Preoperative testing before cataract surgery does not improve outcomes and is not recommended.

Introversion and medical student education: challenges for both students and educators.

ISSUE: Introversion is one of the personality factors that has been shown to be associated with performance in medical school. Prior cross-sectional studies highlight performance evaluation differences between introverted and extraverted medical students, though the mechanisms and implications of these differences remain relatively unexplained and understudied. This gap in the literature has become more salient as medical schools are employing more interactive learning strategies into their curricula which may disproportionately challenge introverted learners. EVIDENCE: In this article, we provide an overview and working definition of introversion as a valid construct occurring on a continuum. We apply a goodness of fit model to explore how various medical training contexts may be more or less challenging for introverted students and the potential consequences of a poor fit. As preliminary support for these hypothesized challenges, we share observations from students self-identified as introverts. Examples include introverted students feeling at times like misfits, questioning a need to change their identity to succeed in medical school, and being judged as underperformers. We offer pragmatic suggestions for improving the fit between introverted students and their training contexts, such as teachers and students pausing between a question being asked and the initial response being offered and teachers differentiating between anxious and introverted behaviors. We conclude with suggested areas for future qualitative and quantitative research to examine how medical school curricula and the teaching environment may be differentially impacting the learning and health of introverted and extraverted students. IMPLICATIONS: Extraverted behaviors will continue to be an important part of medical training and practice, but the merits of introverted behaviors warrant further consideration as both medical training and practice evolve. Educators who make manageable adjustments to current teaching practices can improve the learning for both introverted and extraverted styles of academic engagement.

When to Order a Contrast-Enhanced CT.

Family physicians often must determine the most appropriate diagnostic tests to order for their patients. It is essential to know the types of contrast agents, their risks, contraindications, and common clinical scenarios in which contrast-enhanced computed tomography is appropriate. Many types of contrast agents can be used in computed tomography: oral, intravenous, rectal, and intrathecal. The choice of contrast agent depends on route of administration, desired tissue differentiation, and suspected diagnosis. Possible contraindications for using intravenous contrast agents during computed tomography include a history of reactions to contrast agents, pregnancy, radioactive iodine treatment for thyroid disease, metformin use, and chronic or acutely worsening renal disease. The American College of Radiology Appropriateness Criteria is a useful online resource. Clear communication between the physician and radiologist is essential for obtaining the most appropriate study at the lowest cost and risk to the patient.

Vision loss in older persons.

Family physicians have an essential role in assessing, identifying, treating, and preventing or delaying vision loss in the aging population. Approximately one in 28 U.S. adults older than 40 years is visually impaired. Vision loss is associated with depression, social isolation, falls, and medication errors, and it can cause disturbing hallucinations. Adults older than 65 years should be screened for vision problems every one to two years, with attention to specific disorders, such as diabetic retinopathy, refractive error, cataracts, glaucoma, and age-related macular degeneration. Vision-related adverse effects of commonly used medications, such as amiodarone or phosphodiesterase inhibitors, should be considered when evaluating vision problems. Prompt recognition and management of sudden vision loss can be vision saving, as can treatment of diabetic retinopathy, refractive error, cataracts, glaucoma, and age-related macular degeneration. Aggressive medical management of diabetes, hypertension, and hyperlipidemia; encouraging smoking cessation; reducing ultraviolet light exposure; and appropriate response to medication adverse effects can preserve and protect vision in many older persons. Antioxidant and mineral supplements do not prevent age-related macular degeneration, but may play a role in slowing progression in those with advanced disease.

Patients' understanding and use of snack food package nutrition labels.

PURPOSE: Little information exists on how patients in medical practice use food package nutrition labels. We theorized that patients in a general medical practice might not make the distinction between serving size and total package nutrition information, and this might lead to obesity. METHODS: Ninety patients between ages of 18 and 65 attending the St. Francis/University of Tennessee Family Practice Center were interviewed to determine whether they could calculate the total calories in sample snack food packages that contained more than one serving. RESULTS: Ninety percent of our patient sample correctly identified the number of calories per individual serving, but only 37% were able to recognize that the sample packages contained multiple servings. Confusion between calories per serving size and total calories per package was correlated with lower educational levels (P =.011) and with the presence of cardiovascular heart disease in our patient sample. CONCLUSIONS: Our patients tended to think of a multiple serving package as one serving. They underestimated and under-reported caloric intake from snack food sources. We conclude that snack food labels as actually used by patients do not lead to informed dietary choices. These findings could impact our understanding and management of the obesity epidemic in the United States.

Rosacea: a common, yet commonly overlooked, condition.

Rosacea is a common, but often overlooked, skin condition of uncertain etiology that can lead to significant facial disfigurement, ocular complications, and severe emotional distress. The progression of rosacea is variable; however, typical stages include: (1) facial flushing, (2) erythema and/or edema and ocular symptoms, (3) papules and pustules, and (4) rhinophyma. A history of exacerbation by sun exposure, stress, cold weather, hot beverages, alcohol consumption, or certain foods helps determine the diagnosis; the first line of treatment is avoidance of these triggering or exacerbating factors. Most patients respond well to long-term topical antibiotic treatment. Oral or topical retinoid therapy may also be effective. Laser treatment is an option for progressive telangiectasis or rhinophyma. Family physicians should be able to identify and effectively treat the majority of patients with rosacea. Consultation with subspecialists may be required for the management of rhinophyma, ocular complications, or severe disease. (Am Fam Physician 2002;66:442.)