Primary Screening in Renal Patients
Nephrologists have an important role to play in identifying and addressing behavioral risk factors.
The medical care care of patients with renal disease includes notonly disease-specific care but preventive and general care as well as the treatment of minor acute illnesses, according to Kevin M. Fosnocht, MD, clinical assistant professor of medicine at the University of Pennsylvania School of Medicine in Philadelphia.
Most nephrologists provide primary care to their patients with CKD, and most patients with CKD view their nephrologist as their primary care provider (Am J Kidney Dis. 1998;31:574-583). Patients with CKD are at increased risk of cardiovascular disease, cancer, depression, and other diseases, some of which are associated with high-risk behaviors.
Disease screening and behavioral modification are important aspects of primary care in patients with CKD. Dr. Fosnocht spoke about primary care in nephrology at the American Society of Nephrology's Renal Week 2006 in San Diego.
Guidelines for risk factor screening and intervention typically focus on single behavioral risk factors, but most patients present with, and are screened for, multiple risk factors (Am J Prev Med. 2004;27:2 Suppl:18-24). Among the most common preventable risk factors in the U.S. adult population are cigarette smoking, physical inactivity, risky drinking of alcoholic beverages, and poor dietary habits.
Simple screening and counseling interventions can help identify and modify these behaviors and thereby have a significant beneficial impact on overall disease incidence and severity.
A useful approach to risk factor identification and intervention in the clinical setting is based on "The 5 A's" (Table). This intervention model is promoted by the U.S. Public Health Service and other groups as an effective means of identifying patients in whom risk factor intervention is indicated, determining readiness to change, and initiating appropriate behavior modifications in those ready to change.
The "5 A's" approach incorporates the use of systematic, validated instruments when available and the principles of motivational interviewing including exploration of ambivalence, reflective listening, reinforcement of positive behaviors, and managing resistance (Br J Health Psychol. 2006;11 Pt 2:319-332).
Cigarette smoking is the leading preventable cause of death in the United States. Tobacco use accounts for 440,000 deaths and $157 billion in health-related economic costs each year in the United States. About 44.5 million people, or 20.9% of the adult population, reported smoking in 2004. Cigarette smoking causes numerous cancers, heart disease, stroke, and chronic obstructive pulmonary disease and is a major risk factor for CKD (Kidney Int. 2007;71:159-166).
About 90% of former smokers quit "cold turkey" or by gradually decreasing the amount smoked. The U.S. Public Health Service currently recommends systematic screening for smoking by clinicians and the initiation of smoking cessation interventions including counseling, nicotine replacement therapy (NRT), pharmacologic treatment, and community-based support programs.
The goal of NRT is to replace nicotine from cigarettes, thereby reducing withdrawal symptoms associated with smoking cessation and helping smokers resist the urge to smoke. NRT is available as a chewing gum, transdermal patch, nasal spray, inhalers and tablets. All of the commercially available forms of NRT are effective as part of a strategy to promote smoking cessation.
NRT increases quit rates approximately 1.5- to twofold (to about 20-40%) regardless of setting. The effectiveness of NRT appears to be largely independent of the intensity of additional support provided to the smoker (Tob Control. 2006;15:280-285).
Bupropion was initially developed for the treatment of major depressive disorder and was licensed as a pharmacotherapy for smoking cessation in 1997. Its main mechanism of action is believed to be via dopamine and noradrenaline reuptake inhibition.
The twice-daily sustained-release formulation of bupropion has been extensively evaluated for smoking cessation and has shown continuous smoking abstinence rates at one year of about 20%. Bupropion is well tolerated with side effects including insomnia, headache, dry mouth, dizziness and nausea. Bupropion is a cytochrome p450 inhibitor and must be used with caution in patients taking drugs metabolized by this enzyme (Drugs. 2000;59:1007-1024.).
Varenicline is the first non-nicotine-containing medication developed with the sole purpose of treating nicotine addiction. The drug was granted marketing approval for smoking cessation in 2006 and received an expedited review because of its significant potential benefit to public health. In placebo-controlled studies, about 44% of patients taking varenicline stopped smoking at the end of 12 weeks, compared with 17% of placebo recipients and 30% of patients taking bupropion.
Patients who successfully quit smoking during varenicline treatment may continue with an additional 12 weeks of treatment to further increase the likelihood of long-term smoking cessation. In clinical trials, the most common adverse effects of varenicline were nausea, headache, vomiting, flatulence, insomnia, and dysgeusia. Varenicline can be administered once daily, and dosage adjustments may be necessary in patients with severe renal insufficiency (Ann Pharmacother. 2007;41:95-9).