The elderly are the single largest users of medication in the United States and account for 25% of all drug purchases. Over 80% of the elderly population take more than two medications each day. Older adults are at high risk for nutritional problems. Frequent use of medications for chronic disease and minor complaints adds to the potential for nutrient deficiencies. As a person ages, medications are not metabolized as well and vulnerability to side effects increases. The use of several medications at once compounds the risk for nutritional deficiencies. Errors in dose can more easily occur in seniors medicating themselves with several drugs.
Drugs interact with nutrition in the following ways:
- Food can increase or decrease absorption of drugs
- Components of the diet change the rate of drug use in the body
- Drugs interfere with nutrient pathways, increase excretion and change nutrient needs
- Drugs affect appetite, taste, and food intake
Antihistamines, steroids, tranquilizers, and antidepressants can increase appetite and lead to weight gain. Several drugs, including alcohol and amphetamines, lower appetite and might lead to malnutrition. Digitalis and cancer drugs cause nausea and vomiting. D-penicillamine used to treat rheumatoid arthritis can lead to loss of taste, as can diuretics, antibiotics, anticancer drugs, and drugs used to treat Parkinson's disease and hypertension. Unpleasant taste changes might result in too little food intake and malnutrition.
Drugs that interfere with absorption of vitamins, such as colchicines, can impair vitamin B12 absorption and might lead to anemia. Alcohol interferes with thiamin and folic acid absorption, which increases nerve problems and anemia. Laxatives can produce deficiencies of fat soluble vitamins. The antibiotic neomycin has the same effect.
Other drugs lead to mineral depletion. Alcohol and some diuretics cause excretion of potassium, zinc, and magnesium. Regular use of aspirin causes the stomach to bleed, leading to iron deficiency and anemia. Antacids can produce phosphate deficiency, which leads to sever muscle weakness and convulsions.
The above is just a few of the hundreds of drug nutrient interactions that can occur.
