Drug Disease

the undesirable or harmful side effects of drugs.

Drug diseases are of three basic types: drug allergy, the most common group (to 90 percent of all cases of drug disease); toxic drug disease; and teratogenic drug disease (causing disturbances in the development of the embryo). A combined toxic-allergic effect is sometimes also noted.

Allergy to medicines is increasing as a consequence of the increase both in the production of various types of medicines (antibiotics, hormonal and other synthetic preparations) and in the number of allergens (synthetic substances, various dusts, new forms of food substances). Allergic reactions to nonmedicinal allergens (for example, to food allergens—cranberries, eggs, and so forth) increase the body’s nonspecific sensitivities to drugs. Hereditary and constitutional predispositions to allergy are also of some significance.

Medicines and the products of their oxidation and decomposition may be allergenic. The medicines or their metabolic products usually combine in the body with blood proteins (albumins), forming compounds that can also cause drug allergies.

The clinical picture of a drug disease may be expressed in local inflammatory processes on those areas of the skin that haved touched the medicine (drug contact dermatitis). An extremely severe expression of drug disease is anaphylactic shock. Drug disease may have a variety of manifestations, including hemorrhagic purpura (hemorrhage of the skin and viscera), acute urticaria, and bronchial asthma. Drug allergy can be avoided by introducing drugs to allergic patients with extreme care and by refraining from introducing drugs that have proven to be allergenic. The treatment of drug allergy depends on the allergy’s manifestations.

The toxic effects of drugs may also take a variety of forms. Many drugs are toxic in large (nontherapeutic) doses. A few drugs (for example, certain antitumor preparations) have a teratogenic effect (that is, they cause defects in the development of the embryo). The teratogenic effect of the foreign somnifacient thalidomide (Federal Republic of Germany) is well known. The drug was removed from manufacture in the 1960’s. The catastrophe caused by thalidomide aroused intensive study of the teratogenic effects of other drugs, with the aim of preventing such complications in the future.