Pharmacology Food-drug interactions Careful drug selection and patient counseling can reduce the risk in older patients
Eric R. Leibovitch, MD, FACP • Robert L. Deamer, PharmD, BCPSLeslie A. Sanderson, RD, CNSD
Older patients are at high risk for food-drug interactions. These
patients are commonly on multiple medications for chronic medical
conditions. Age-related physiologic changes affecting drug absorption,
distribution, metabolism and excretion, as well as drug action occur in
these patients, and this variability in drug action may be further
potentiated by interactions with foods. The most prominent
interactions involve drug absorption from the GI tract; however
tions. [Editor’s note: Foods in the cover
alterations in drug metabolism are also highly significant. Food-drug
interactions have been reported amongst a wide range of therapeutic
drug classes, including, but not limited to, cardiovascular, psychoactive,
anti-infective, endocrinologic, gastrointestinal, and respiratory agents.
Health care providers can prevent significant drug therapy-related
morbidity by carefully selecting drugs for geriatric patients and
thoroughly counseling these patients about drug interactions with the
Leibovitch ER, Deamer RL, Sanderson LA. Food-drug interactions: Care drug selection and
ication effects are frequently altered by
patient counseling can reduce the risk in older patients. Geriatrics 2004; 59(Mar):19-33.
Key words: Food • interaction • drug absorption • drug distribution
ing drug absorption, distribution, me-tabolism and excretion, as well as drugaction. In addition, endocrine dys-function, restrictive diets, and alco-
Nrecently in the medical litera- caused by drug interactions are of potentiate these interactions.Additional
aged cheeses are just a few of the every-
Dr. Leibovitch is senior attending physician and coordinator of internal medicineeducation, Ventura County Medical Center; and adjunct professor of medicine, Uni-
versity of California Los Angeles School of Medicine.
Dr. Deamer is the former director of pharmacotherapy education and research,
family practice residency program, department of medical education, Ventura County
Medical Center, assistant clinical professor, University of California Los AngelesSchool of Medicine and University of Southern California School of Pharmacy; he is
currently drug education program coordinator; Kaiser Permanente, Southern California.
Disclosure: The authors have no real or apparent conflicts of interest related to thesubjects under discussion.
March 2004 Volume 59, Number 3 Geriatrics Food-drug interactions
Table Pharmaceutical agents implicated in significant food-drug interactions in older adults
Medication Effects of food Potential clinical implications Cardiovascular agents
For Client Review Only. All Rights Reserved. Advanstar Communications Inc. 2003
CNS medications
Triazolam Carbamazepine Nefazodone Trazodone HClQuetiapine fumarate
Geriatrics March 2004 Volume 59, Number 3 Food-drug interactions
Pharmaceutical agents implicated in significant food-drug interactions in older adults (continued)
Medication Effects of food Potential clinical implications CNS medications, continued
High Na diet ↓ Li blood levelsLow Na diet ↑ Li blood levels
Anti-infective agents
↓ (substantial) absorption with cations
beans, pickled fish, yeast extracts, red wines, overripe avocados, or figs)
↓ (substantial) absorption with cations
Ciprofloxacin Levofloxacin All other fluoroquinolones
March 2004 Volume 59, Number 3 Geriatrics Food-drug interactions
Pharmaceutical agents implicated in significant food-drug interactions in older adults (continued)
Medication Effects of food Potential clinical implications Endocrine medications GI tract medications Respiratory tract medications Allergic conditions
DiphenhydramineClemastine fumarateFexofenadine HClCetirizine HCl
Immunosuppressants
Prepared for Geriatrics by Eric R. Leibovitch, MD, FACP, Robert L. Deamer, PharmD, BCPS, and Leslie A. Sanderson, RD, CNSD, using informationfrom references 1-6 and 13-15. Geriatrics March 2004 Volume 59, Number 3 Food-drug interactions
mechanism for food-drug interaction. Drug absorption may be the most
tions.9,10 Aging itself is associated with
cal and dietary references are key.4-6 Be-
face of the GI tract.9 In some instances,
remains unknown.
with anticholinergic properties (eg, tra-
ditional antihistamines; diphenoxylateHCl with atropine sulfate) slow gastric
also alter gastric pH, which affects therate of dissolution of many drugs. Milk
structed to take these agents on an empty
only and to stay upright and consume
acidic fruit juices, vegetable juices, car-
nothing else for at least 30 minutes.
(relating to the drug’s absorption, dis-
tribution, metabolism, and excretion).
fluoroquinolones as mentioned above.
in vitamin K (eg, asparagus, red leaf let-
tation as well as improve absorption.
farin, making it essential to counsel pa-
tients to limit any variability in vitamin
tion of penicillins. Thus, physicians are
Geriatrics March 2004 Volume 59, Number 3 Food-drug interactions
with older adults whenever possible.
content of the diet, and the transit time
ilar effects. A high-fat diet can compete
ticular) or consuming high quantitiesof highly processed foods. Alternately,
fect of either high carbohydrate diets or
Elimination of drugs. Drugs are elim-
to take medications in regards to meals. Drug distribution. Many factors in-
10.Thomas JA. Drug-nutrient interactions.
tions: Avoiding therapeutic paraly-sis. J Clin Psychiatry 1998;
13.Williams L, Davis JA, Lowenthal DT. Drug metabolism. Nutrients can ei-
ample is the effect grapefruit juice (GFJ)
used drugs.7,8 By inhibiting intestinal—
10th ed. Philadelphia, Pa: SaundersCompany; 2000:399-414.
exactly as instructed. G
March 2004 Volume 59, Number 3 Geriatrics
Accelerating and Broadening Australia’s Microeconomic Reform Agenda Speaker: Bill Scales AO, Chairman, Industry Commission, Abstract Australia is undoubtably a nation rich with opportunities, with extensive social andeconomic infrastructure, stable and responsible government, and abundant naturaland developed resources. But Australia also faces some significant challenges, includ
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