This section is from the book "Practical Dietetics With Special Reference To Diet In Disease", by William Gilman Thompson. Also available from Amazon: Practical Dietetics with Special Reference to Diet in Disease.
1. Alkalies are best given shortly before meals, unless designed to neutralise hypersecretion of hydrochloric acid.
2. Acids should be given within half an hour after meals.
3. Bitters should be given before meals.
4. Remedies such as iron and arsenic, which may prove somewhat irritant to mucous membranes, should be given either soon after the regular meals or after taking some simple article of food. Ammonium carbonate and potassium iodide, for example, may be prescribed in milk.
5. Most cough medicines, cardiac tonics, diuretics, and systemic remedies which are not especially irritating to the stomach should be taken between meals. They will be more promptly absorbed from an empty stomach, and are less liable to be altered in composition by digestive fluids or to inhibit digestion.
6. Remedies designed to act in the intestine and not in the stomach, such as salol, should be given at the end of gastric digestion, when the stomach contents are about to pass into the intestine.
7. Saline laxatives should always be taken at least half an hour or an hour before meals, preferably before breakfast; but the stronger, more slowly acting cathartics should be given on an empty stomach at night.
Cod-liver oil should be given an hour and a half after meals, or on an empty stomach before retiring.
According to Whitehead, starchy food should be avoided while iodine preparations are being administered, because of the insoluble compound likely to be formed of iodine and starch. Syphilitics, he says, should therefore eat meat and light green vegetables only, in order to get a maximum effect from the remedy. If they are taking very large quantities, such as half an ounce or more a day, this may be advisable, but it is unnecessary for ordinary cases.
Foods and beverages may be often used to disguise the taste of disagreeable or bitter medicines, especially for children. An unpleasant dose may often be smuggled down in a teaspoonful of jam or a little molasses, and quinine is somewhat disguised by mixture in chocolate lozenges. It may be given in solution to adults in coffee. Castor oil is given floating on coffee or beer. Both milk and Vichy partially disguise the taste of potassium iodide.
Milk is an excellent vehicle for powders, such as bismuth, magnesium carbonate, or sulphonal. Many bitter medicines may be followed by a lump of sugar or a strong peppermint lozenge, or the mouth may be rinsed with a little brandy and water. Chocolate is also a good vehicle for the administration of bitter medicines, and it may be employed to emulsify cod-liver oil.