NAPLEX / Geriatrics

Answer: D. In Table 3, all these conditions are reasons to avoid benzodiazepines. These medications affect the CNS and the elderly population can be more sensitive. With benzodiazepines having a depressant effect on the CNS it makes since that patients may be at risk for these conditions since the patient’s balance, reaction time, and cognitive abilities would be reduced.
Reference:
Radcliff, Sue, et al. "American Geriatrics Society 2015 updated beers criteria for potentially inappropriate medication use in older adults." JOURNAL OF THE AMERICAN GERIATRICS SOCIETY 63.11 (2015): 2227-2246.

Answer C. Glipizide and Gliclazide are considered short-acting sulfonylureas and are listed as alternatives to long acting sulfonylureas like chlorpropamide and glyburide.
Reference:
Hanlon J, Semla T, Schmader K. Alternative Medications for Medications in the Use of High-Risk Medications in the Elderly and Potentially Harmful Drug-Disease Interactions in the Elderly Quality Measures. Journal of the American Geriatrics Society. 2015;63(12):e8-e18. doi:10.1111/jgs.13807.

Answer B. Second generation antihistamines like cetirizine should be used instead of first generation antihistamines like clemastine and hydroxyzine.
Reference:
Hanlon J, Semla T, Schmader K. Alternative Medications for Medications in the Use of High-Risk Medications in the Elderly and Potentially Harmful Drug-Disease Interactions in the Elderly Quality Measures. Journal of the American Geriatrics Society. 2015;63(12):e8-e18. doi:10.1111/jgs.13807.

Answer A. Mineral oil should not be administered orally in the elderly due to the risk of aspiration. There are safer alternatives.
Reference:
American Geriatrics Society 2015 Updated Beers Criteria for Potentially Inappropriate Medication Use in Older Adults. Journal of the American Geriatrics Society. 2015;63(11):2227-2246. doi:10.1111/jgs.13702

Answer A. With aging, blood pressure and total peripheral resistance increase, however, a decrease in cardiac output is seen. A progressive decline in baroreceptor sensitivity is a characteristic feature of human aging as is a decrease in Beta-adrenergic receptor sensitivity.
Reference:
1. Martin WH 3rd e. Effects of aging, gender, and physical training on peripheral vascular function. - PubMed - NCBI. Ncbinlmnihgov. 2016. Available at: https://www.ncbi.nlm.nih.gov/pubmed/1860209. Accessed October 12, 2016.
2. O'Mahony D e. Reduced baroreflex sensitivity in elderly humans is not due to efferent autonomic dysfunction. - PubMed - NCBI. Ncbinlmnihgov. 2016. Available at: https://www.ncbi.nlm.nih.gov/pubmed/10600664. Accessed October 12, 2016.

Answer: A. There is a progressive reduction in total body water and lean body mass that occurs and which results in a relative increase in body fat. Renal mass decreases with age and reflects the reduction in nephrons. Both renal plasma flow and as well as glomerular filtration rate decline with age.
Reference:
1. Mangoni AJackson S. Age-related changes in pharmacokinetics and pharmacodynamics: basic principles and practical applications. British Journal of Clinical Pharmacology. 2003;57(1):6-14. doi:10.1046/j.1365-2125.2003.02007.x.
2. Summary of the Updated American Geriatrics Society/British Geriatrics Society clinical practice guideline for prevention of falls in older persons. J Am Geriatr Soc 2011;59:148-57.


Answer D. Expiratory flow rates decrease with aging and typically show changes in the flow-volume curves. Other age-related changes that occur in the lungs include weakening of the respiratory muscles as well as a decrease in lung measures of lung function such as vital capacity, which is the maximum amount of air that can be breathed out following a maximum inhalation.
Reference:
1. Janssens J, Pache J, Nicod L. Physiological changes in respiratory function associated with ageing. European Respiratory Journal. 1999;13(1):197-205. Available at: http://erj.ersjournals.com/content/13/1/197.long. Accessed October 13, 2016.
2. System E. Effects of Aging on the Respiratory System. Merck Manuals Consumer Version. 2016. Available at: https://www.merckmanuals.com/home/lung-and-airway-disorders/biology-of-the-lungs-and-airways/effects-of-aging-on-the-respiratory-system. Accessed October 13, 2016.

Answer B. Aging has been associated with various GI changes such as: a decrease in splanchnic blood flow, delayed gastric emptying, and an increase in gastric pH.
Reference:
1. Mangoni AJackson S. Age-related changes in pharmacokinetics and pharmacodynamics: basic principles and practical applications. British Journal of Clinical Pharmacology. 2003;57(1):6-14. doi:10.1046/j.1365-2125.2003.02007.x.

Answer D. Blood flow to the liver may be reduced with aging by 25-47% and dermal thickness, vascularity, and cellularity also decreases with age. There is a progressive reduction in total body water and lean body mass that occurs and which results in a relative increase in body fat.
Reference:
1. Mangoni AJackson S. Age-related changes in pharmacokinetics and pharmacodynamics: basic principles and practical applications. British Journal of Clinical Pharmacology. 2003;57(1):6-14. doi:10.1046/j.1365-2125.2003.02007.x.
2. Summary of the Updated American Geriatrics Society/British Geriatrics Society clinical practice guideline for prevention of falls in older persons. J Am Geriatr Soc 2011;59:148-57.


Answer D. Pharmacokinetic changes in the elderly such as an increase in volume of distribution of lipid soluble drugs, results in prolonged elimination half-life of these agents. Thus, polar drugs that are mainly water-soluble tend to have smaller volumes of distribution, resulting in higher serum levels in older patients. Serum albumin (binds to acidic drugs) decrease with age, resulting in an increased free fraction in plasma of high protein bound acidic drugs.
Reference:
Mangoni AJackson S. Age-related changes in pharmacokinetics and pharmacodynamics: basic principles and practical applications. British Journal of Clinical Pharmacology. 2003;57(1):6-14. doi:10.1046/j.1365-2125.2003.02007.x.
2. Summary of the Updated American Geriatrics Society/British Geriatrics Society clinical practice guideline for prevention of falls in older persons. J Am Geriatr Soc 2011;59:148-57.


Answer D. Hepatic metabolism includes phase 1 reactions (oxidation, reduction and hydroxylation) and phase 2 reactions (conjugation with glucuronate, sulphate or acetate). Phase 1 reactions, are reduced during the aging process, probably due to a combination of reduced hepatic blood flow (35% reduction in hepatic blood flow in the elderly) and reduced hepatic volume. Thus, drug metabolism, particularly first-pass metabolism (e.g. propranolol, labetalol, verapamil, metoclopramide, opioids) may be considerably reduced in elderly people, which in return may increase their drug concentrations.
Reference:
1. Hughes. Prescribing for the elderly patient: why do we need to exercise caution?. British Journal of Clinical Pharmacology. 2002;46(6):531-533. doi:10.1046/j.1365-2125.1998.00842.x.
2. Summary of the Updated American Geriatrics Society/British Geriatrics Society clinical practice guideline for prevention of falls in older persons. J Am Geriatr Soc 2011;59:148-57.


Answer B. The main effect of an increased volume of distribution is a prolongation of half-life. An increase VD and half-life have been observed for agents such as diazepam. Although, in general, the volume of distribution of most benzodiazepines tends to increase with age, for reason that are not clear, the VD of alprazolam (short half-life BZD) specifically decreases in elderly men but remains unchanged in elderly women. Triazolam is also considered to have a short half-life, compared to diazepam (highly lipophilic). Phase 2 reactions usually involve conjugation of phase 1 metabolites and appear to be unchanged by the ageing process although they may be impaired in some frail elderly people, an example of this would be lorazepam (no accumulation due to inactive metabolites.)
Reference:
1. Mangoni AJackson S. Age-related changes in pharmacokinetics and pharmacodynamics: basic principles and practical applications. British Journal of Clinical Pharmacology. 2003;57(1):6-14. doi:10.1046/j.1365-2125.2003.02007.x.
2. Summary of the Updated American Geriatrics Society/British Geriatrics Society clinical practice guideline for prevention of falls in older persons. J Am Geriatr Soc 2011;59:148-57.


Answer D. Lithium, cimetidine, and digoxin distribution in elderly is influenced by physiologic change related to body composition, particularly total body water. There is a decrease in total body water with advancing age, which results in a lower volume of water per kilogram of body weight. So the same dose of these agents in an older person would have less water for them to distribute into, resulting in a higher serum lithium concentration.
Reference:
1. Mohandas E, Rajmohan V. Lithium use in special populations. Indian Journal of Psychiatry. 2007;49(3):211. doi:10.4103/0019-5545.37325.
2. Hughes. Prescribing for the elderly patient: why do we need to exercise caution?. British Journal of Clinical Pharmacology. 2002;46(6):531-533. doi:10.1046/j.1365-2125.1998.00842.x.

Answer D. An unbiased Cockcroft-Gault creatinine clearance can be calculated using actual body weight in underweight patients and ideal body weight in patients of normal weight. Using ABW(0.4) for overweight, obese, and morbidly obese patients appears to be the least biased and most accurate method for calculating their Cockcroft-Gault creatinine clearance. In addition, the common practice of rounding or replacing low Serum Creatinine values with an arbitrary value of 1.0 mg/dl for use in the CG equation should be avoided. Rounding S(c) (r) in patients with low S(c) (r) did not improve accuracy or bias of the creatinine clearance calculations.
Reference:
1. Dowling T, Wang E, Ferrucci L, Sorkin J. Glomerular Filtration Rate Equations Overestimate Creatinine Clearance in Older Individuals Enrolled in the Baltimore Longitudinal Study on Aging: Impact on Renal Drug Dosing. Pharmacotherapy: The Journal of Human Pharmacology and Drug Therapy. 2013;33(9):912-921. doi:10.1002/phar.1282.
2. Winter MA e. Impact of various body weights and serum creatinine concentrations on the bias and accuracy of the Cockcroft-Gault equation. - PubMed - NCBI. Ncbinlmnihgov. 2016. Available at: https://www.ncbi.nlm.nih.gov/pubmed/22576791. Accessed October 13,