Therapeutic
Review Harmony with drugs and food
C. BRIAN TUTTLE,* M SC PHM
There is a growing awareness among professionals who care at mealtime. Another aspect of this topic - the important
for patients' drug and nutritional requirements that constitu- problem of drug-induced nutritional deficiencies - cannot be
ents of foods and beverages can modify the predictable effect adequately dealt with here.
of drugs. Changes in the rate or extent of drug absorption or The following six tables may be used as a guide in selecting
metabolism and occasionally exaggerated clinical responses the most appropriate schedule for drug administration in
may be attributed to the concurrent ingestion of foodstuffs relation to food intake. They are intended to promote the goal
and medications. The absence of food at a critical interval of optimum drug response with minimal gastrointestinal side
may also give rise to untoward effects from certain drugs. effects. The tables are not comprehensive: they are guidelines
As well as the clinical response, the patient's acceptance of only. Tables I and III in particular should be viewed as
medication can be influenced by the timing of drug adminis- allowing the flexibility necessary to compensate for interpa-
tration in relation to food intake. Attention to the role of food tient variability. For example, while the drugs listed in Table
as a means of preventing "stomach upset" can increase the I should be taken on an empty stomach to achieve optimum
patient's compliance as well as protect the stomach from the blood levels (which may be at the expense of some gastric
persistent onslaught of ulcerogenic drugs, such as acetylsalicy- upset), in many instances the patient can take the medication
lic acid, iron and potassium salts. with a light meal if compliance is threatened. The footnotes to
Nevertheless, for certain drugs the potential benefits of each table help explain this flexibility in interpretation.
reduced gastric upset can be outweighed by the decrease in
bioavailability that results when the drug's absorption is Table 11-Drugs to be taken 1 hour after a meal
significantly impaired by the presence of food. Some drugs
are destroyed in the highly acid environment of the stomach Generic name Trade name(s)
Antacid preparations' Amphojel, Gelusil, Maalox,
Adapted from an article published in Drugs and Therapeutics for Mylanta-2 Plain, Riopan,
Maritime Practitioners (1980; 3: no 5) Univol
Antacid-antiflatulent preparations2 Amphojel 65, Diovol, Duatrol,
*Assistant director of pharmacy, drug information and education, Maalox Plus, Mylanta, Rioplus
Camp Hill Hospital, Halifax 1. The buffering effect of food on acid secretion begins to decline after about 1 hour, so
Reprint requests to: Mr. C. Brian Tuttle, Drug information centre, unless symptoms appear earlier this is the optimum time to give an antacid.
Camp Hill Hospital, 1763 Robie St., Halifax, NS B3H 3G2 2. Some are recommended for use between meals.
Table I-Drugs to be taken on an empty stomach
Generic name Trade name(s) Generic name Trade name(s) Generic name Trade name(s)
Acetylsalicylic acid Ecotrin, Entrophen, Glycopyrrolate2 Robinul Pentaerythritol Peritrate,
(enteric-coated) Ic Triaphen-10 Iron preparationsid tetranitratelac Peritrate SA
Ampicillinlab Ampicin, Penbritin Ferrous fumarate Palafer, Tolifer Phentermine3b lonamin
Atropine2 In Lomotil, Donnatal Ferrous gluconate Fergon, Fertinic Piperazine saltsle Antepar, Entactyl
Belladonna2 In Donnatal Ferrous succinate Cerevon Propantheline2 Pro-Banthine
Captoprill Capoten Ferrous sulfate Fesofor, Ferrosulph Pyrvinium's Pamovin, Vanquin
Carbenoxolone3a Biogastrone, Iron preparations Quinacrinele Atabrine
Duogastrone, (slow-release; Quinidine bisulfatelc Biquin Durules
Clidinium2 In Librax coated)l Fero-Grad, Slow-Fe Rifampinia Rimactane
Cloxacillinia,b Orbenin, Tegopen lsoniazid"a Rimifon Sucralfate3a Sulcrate
Dicyclomine2 Bentylol Lincomycinla Lincocin Tetracyclinesla
Diethylpropion3b Tenuate Mazindol3b Sanorex Demeclocyline Declomycin
Erythromycin Niclosamidele Yomesan Tetracycline Achromycin, Tetracyn
BaselaM Erythromid, Robimycin Penicillaminela Cuprimine Oxytetracycline Terramycin
Stearatela,b Erythrocin Pencillin Gla,b Falapen, Hylenta, Theophylline Theo-Dur
Fenfluramine3a Pondimin Megacillin (slow-release)
1. To be taken 1 hour before or 2 hours after a meal:
a. Gastrointestinal absorption may be significantly impaired when these drugs are taken with a meal. The absorption of most pencillins (exceptions: amoxicillin [Amoxil] and penicillin V [Pen Vee,
V-Cillin K] ), tetracyclines (exceptions: doxycycline [Vibramycin], minocycline [Minocin]) and erythromycin preparations (exceptions: the estolate [Ilosone] and the ethylsuccinate [EES-200 and
-400] ) is impaired by the presence of food in the stomach. If stomach upset becomes a problem with a tetracycline the drug can be taken with a light meal but not with milk. Absorption of the
sulfonamides does not appear to be impaired by food; there may be a delay in absorption with no clinical consequences.
b. These drugs should be taken with a full glass of water. They are inactivated to various degrees by acid secretions of the stomach and more so if taken at mealtime, when stomach emptying is
slow and acid output high. Exceptions include amoxicillin (Amoxil), penicillin V (Pen Vee, V-Cillin K), erythromycin estolate (Ilosone) and erythromycin ethylsuccinate (EES-200 and -400), which are
acid-stable and well absorbed when taken with a meal. The enteric-coated E-Mycin appears to be equally effective when taken with and without food.
c. Enteric-coated and sustained-release preparations may not release medication as expected when mixed with food.
d. For optimum absorption iron products are best taken between meals with a full glass of water; however, if stomach upset occurs or is to be avoided, the medication should be taken with or
after meals but not with milk.
e. Although not true for all anthelmintics, the action of these drugs (piperazine and pyrvinium for roundworms and niclosamide and quinacrine for tapeworms) is best when they are taken on an
empty stomach. The surface contact between drug and parasite is diminished in the presence of food.
2. To be taken half an hour before a meal: Anticholinergic agents are given to inhibit vagal stimuli thought to be responsible for gastric acid hypersecretion and hypermotility in peptic ulcer disease.
They are more effective against "basal" than against "stimulated" secretion.
3. To be taken 1 hour before a meal:
a. Ulcer healing depends upon maximum contact between drug and ulcer base.
b. For maximum psychologic and pharmacologic effectiveness.
CMA JOURNAL/MAY 15, 1982/VOL. 126 1161
Table 1l-Drugs to be taken with food
Generic name Trade name(s) Generic name Trade name(s) Generic name Trade name(s)
Acetylsalicylic acid' Various Hydralazine4 Apresoline Phenytoinl4a Dilantin
Allopurinoll Zyloprim Hydrochlorothiazidel,4a Hydrodiuril, Dyazide Piroxicam' Feldene
Aminophyllinel Corophyllin Hydrocortisonel Cortef Potassium salts' Kaochlor, Kaon,
Betamethasone' Betnesol, Betnelan Ibuprofen' Motrin, Amersol Kay Ciel, K-Lyte
Biperidin' Akineton Indomethacini Indocid Prednisolonel Delta-Cortef
Bromocriptinel Parlodel Iron preparationsia Prednisonel Colisone, Deltasone
Carbamazepine4a Tegretol Ferrous fumarate Palafer, Tolifer Probucol4s Lorelco
Chlorothiazidel Diuril Ferrous gluconate Fergon, Fertinic Procyclidinel Kemadrine
Chlorpromazinel Largactil Ferrous succinate Cerevon Promethazinel Phenergan
Chlorpropamidel Diabinese Ferrous sulfate Fesofor, Ferrosulph Propranolol4b Inderal
Chlorthalidonel Hygroton Isosorbide dinitrate2 Coronex, Isordil Propoxyphene4a Darvon
Cholestyramine3a Questran Ketoprofeni Orudis Reserpinel Serpasil
Cimetidine3a Tagamet Levodopal Larodopa, Sinemet Spironolactone4a Aldactone
Clofibrate' Atromid-S Methotrexatel _ Sulfasalazinel Salazopyrin
Dexamethasone' Decadron Metoclopramide3b Maxeran Sulfinpyrazone' Anturan
Diclofenac' Voltaren Metoprolol4b Betaloc, Lopressor Sulindaci Clinoril
Dicoumarol4 Dufalone Metronidazolel Flagyl Thioridazinel Mellaril
Digestants and Accelerase, Donnazyme, Minocyclinelb Minocin Theophyllinel Elixophylline, Theolair
enzyme preparations2 Entozyme, Fermentol, Nalidixic acidi NegGram Tolbutamidel Mobenol, Orinase
Ultrase, Viokase Naproxen' Naprosyn Tolmetini Tolectin
Doxycyclinelb Vibramycin Nitrofurantoin4a Furanex, Macrodantin Triamterenel Dyrenium, Dyazide
Ethacrynic acid, Edecrin Oxtriphyllinel Choledyl Trihexyphenidyll Artane
Fenoprofeni Nalfon Oxyphenbutazonel Tandearil Trimeprazinel Panectyl
Glyburide2 Diabeta Pancrelipase3a Cotrazym Zomepirac' Zomax
Griseofulvin4a Fulvicin, Grisovin Phenylbutazonel Butazolidin
1. To be taken immediately before, with or after a meal, or with food or milk to prevent or minimize stomach upset. Depending upon the amount and type of food taken, the absorption of these drugs
may be delayed, but their total bioavailability will not be significantly affected. There is considerable variation among patients in the amount of gastric distress experienced with these drugs. Some
need only to take their medication with milk or a light snack, while others, because of marked epigastric or abdominal distress, or for other medical reasons, should take their medication with food to
protect the stomach.
a. If stomach upset develops when taken on an empty stomach, iron preparations can be taken with food.
b. The absorption of doxycycline, and minocycline, unlike that of other tetracyclines, is not significantly impaired by food; in fact, these two drugs may be better tolerated when taken with food.
2. To be taken with a meal to prevent systemic side effects.
3. To be taken with a meal (a, immediately before; b, before or just after, in motility disorders) to provide a clinical effect.
4. May be taken with a meal for enhanced bioavailability.
a. Gastrointestinal absorption is enhanced.
b. Metabolism of the drug during its first passage through the liver is reduced; this does not mean that these drugs are less effective when taken on an empty stomach, but only that somewhat
higher blood levels can be expected when they are taken with a meal.
Table IV-Drugs to be taken with liberal amounts of fluid
Generic name Trade name (s) Generic name Trade name (s) Generic name Trade name (s)
Acetylsalicylic acid Various Iron preparationslc Various Probenecid2a Benemid
(plain)ibMc Methotrexate2 _ Psyllium hydrophilic
Allopurinol2a Zyloprim Methylcellulose2b mucilloid2a Metamucil
Ampicillinld Ampicin, Penbritin Penicillamine2c Cuprimine Sulfinpyrazone2a Anturan
Cloxacillinid Orbenin, Tegopen Penicillin Gid Falapen, Hylenta, Sulfonamidesza Various
Cyclophosphamide3 Procytox Megacillin Tetracyclinel Various
Erythromycin Potassium chloride Kaochlor, Kaon,
Baseld Erythromid, Robimycin (liquid)ilac Kay-Ceil, K-Lyte
Stearateld Erythrocin
1. To be taken with a full glass of water (240 ml [8 oz0) to promote dispersion and dissolution of the drug and thus reduce the risk of esophageal or peptic ulceration, or to minimize acid
degradation in the stomach and enhance bioavailability.
a. Liquid potassium preparations must be diluted with water to avoid gastrointestinal injury. Doses of 20 mmol of potassium should be taken with at least 90 or 120 ml (3 or 4 oz) of cool water,
fruit juice or a carbonated beverage. Higher doses (e.g., 40 mmol) should be taken with 240 ml (8 oz) of water or other fluid.
b. When there is a danger of gastrointestinal bleeding, plain acetylsalicylic acid can be taken with milk or dispersed in 30 ml of an antacid to enhance dissolution in the stomach.
c. Should generally not be taken within 1 hour of bedfime.
d. When these acid-labile drugs are taken on an empty stomach with a full glass of water the fluid volume enhances stomach emptying and dilutes the gastric contents.
2. To be taken with at least 240 ml (8 oz) of water:
a. Patients should try to drink 8 to 10 glasses of water a day to prevent crystalluria or the formation of urinary calculi.
b. Patients should drink a generous quantity of fluid for the bulk-forming effect of these laxatives and to prevent obstruction.
c. It is especially important that patients treated for cysteinuria drink about 500 ml (a pint) of water at bedtime and again during the night, when the urine is more acid.
3. To be followed by 2000 to 3000 ml of fluid to ensure prompt excretion of toxic active metabolites.
Table V-Drugs not to be taken with milk
Acetylsalicylic acid (enteric-coated)2& Ecotrin, Entrophen, Triphen-10 Table VI-Drugs not to be taken with fruit juices or carbonated beverages
Bisacodyl2a Dulcolax
Erythromycin E-Mycin, Erythrocin
(coated)2b Filmtab Generic name Trade name(s)
Ferrous sulfate (liquid, drops) Fer-ln-Sol Ampicin, Penbritin
Tetracyclines' Various Ampicillin
Cloxacillin Orbenin, Tegopen
1. To be taken at least 1 hour before or 1 hour after milk or other dairy products, which Erythromycin
contain sufficient calcium to complex with and render unabsorbable a significant proportion
Base Erythromid, Robimycin
of the dose. Stearate Erythrocin
Penicillin G Falapen, Hylenta, Megacillin
2. To be taken at least 1 hour before or 1 hour after milk.
a. Milk may enhance the dissolution of the enteric coating, which is designed to protect
the stomach from irritation by the drug.
b. Milk may enhance the dissolution of the protective coating, which is designed to protect *Fruit juices and most carbonated beverages are quite acidic and can inactivate many
the acid-labile drug from degradation in the stomach. acid-labile drugs.
1162 CMA JOURNAL/MAY 15, 1982/VOL. 126