Depending on the illness, diet is the first or second priority in the management. One has to note however that there are drug-nutrient interactions. Drugs may affect the intake, absorption and metabolism of some nutrients. Food and nutrients may also affect the absorption and metabolism of certain drugs. Thus it should not be a wonder if malnutrition and/or other disease conditions develop during the course of treatment.
Let us have the case of selected drugs used in cardiac (heart care) which are of many kinds. Anticoagulants such as warfarin, heparin and which is supposed to prevent or slow blood clotting can be affected by vitamin K which promotes blood clotting. Diuretics decrease blood volume by increasing urination, inhibiting sodium and water reabsorption to lower blood pressure. Loop diuretics such as furosemide, torsemide and bumetanide lower blood potassium yet increase uric acid levels, decrease appetite can cause nausea and vomiting, diarrhea and constipation . Thiazide diuretics such as hydrochlorothiazide, chlorthalidone and indapamide also increase potassium levels and decrease appetite. These also increase calcium levels. Potassium sparing diuretics like triamterene, can result to nausea and vomiting and diarrhea.
Another class of commonly-used drugs in cardiac care is ACE inhibitors. These are drugs that decrease resistance in the smaller blood vessels to accommodate more blood and supposedly decrease blood pressure. These are the drugs that end with ”pril” – captopril, enalapril and ramipril among others. Use of these can lead to low blood pressure, can worsen renal (kidney) functioning and increase potassium levels yet decrease appetite. Dry, non-productive cough may also develop.
Beta-blockers are of different kinds like diuretics. Beta-1 blockers such as those ending in “lol” (metoprolol, atenolol, etc) are intended to decrease heart rate and cardiac output, cause nausea, diarrhea, dry mouth, gas or bloating and may mask low blood sugar. Beta-blockers with alpha activity (e.g. carvedilol) promote dilation of smaller blood vessels, can increase weight and cause nausea and vomiting as well as diarrhea.
Calcium channel blockers like amlodipine, nifedipine, diltiazem, verapamil, are intended to relax the blood vessels and thus reduce constriction or resistance in the blood vessels but can cause water retention, nausea, heartburn. HMG-CoA reductase inhibitors like atorvastatin, simvastatin, inhibit or stop production of cholesterol within the body but can lead to nausea, abdominal pain, constipation, diarrhea and flatulence.
Angiotensin II receptor blockers (ARB) like losartan, valsartan and other “tan,” can cause nausea and may increase blood potassium. One has to avoid salt substitutes and has to caution with grapefruit. Digitalis or digoxin, increase strength of heart contractions but can cause diarrhea, loss of appetite and lower stomach pain. Bile acid sequestrants such as cholestyramine and colestipol, are intended to reduce reabsorption of bile acids and cholesterol but may decrease absorption of fat-soluble vitamins (A, D, E, K). and minerals.
