(MONEY Magazine) – The high cost of medicine is enough to make you sick. Last year the average price of prescription drugs jumped 8%, while prices in general were rising only 1%. Doctors could help cure this inflation in no time by prescribing regular doses of less expensive generic drugs instead of brand names. For example, 100 Valium tablets cost about $33, while the same tranquilizer costs $16 in its generic form, diazepam (see the table below). If generics were always prescribed for the roughly 75% of major drugs available in that form, patients and insurers would cut their costs by about $1 billion a year. Yet the Federal Trade Commission estimates that doctors saved no more than $236 million for their patients by writing generic prescriptions in 1984, the latest year for which statistics are available. To defend their high profits on brand-name drugs, pharmaceutical manufacturers have been barraging doctors and pharmacists with advertising, some of which is drawing criticism from medical authorities and government regulators. Generics have the same active ingredients as brand names. When a drug is patented, the manufacturer generally enjoys a 17-year monopoly on its sale and therefore largely controls the price. But once the patent expires, competitors are free to manufacture the drug under its generic name. Generics are cheaper to produce and market. One reason: with no brand image to create, the marketers use little or no advertising. Another: companies often spend millions of dollars proving to the Food and Drug Administration that a new drug is safe and effective, while they need only prove that a generic product is equivalent to the original. The patents on several of the most prescribed drugs have recently expired, causing a bit of a boom in generics. In the past year, for example, such widely prescribed medications as Valium, Inderal (generic name: propranolol), for high blood pressure, and Motrin (generic name: ibuprofen), a painkiller, have appeared in generic form. Before you can buy a generic drug, your doctor must either prescribe it or give permission on the prescription form for the pharmacist to substitute a generic for the brand name specified. ''But not all physicians are so enlightened,'' says Dr. Donald Bennett, director of drugs and toxicology at the American Medical Association. Whenever your doctor writes you a prescription, remind him that generics can save you money. Furthermore, as our table shows, it pays to shop more than one drugstore when you are getting | the prescription filled. While pharmacists pay less for generics than for brand names, they sometimes tack on extra-large markups. Some doctors balk at prescribing generics for fear that they are inferior or unsafe. Brand-name companies have helped to instill this fear, according to the FDA. Dr. Peter Rheinstein, director of its office of drug standards, complains: ''Every time a drug has become available for generic competition, the brand-name manufacturer has launched an advertising campaign to discourage pharmacists and physicians from allowing substitutions. Many of the antigeneric statements are, at least, misleading.'' Generic drug makers must prove to the FDA that their product's bio- equivalency, the rate and extent of absorption of the drug by the human body, approximates the brand name's. If a drug is absorbed too slowly, it may be ineffective. If too fast, it may be harmful. Brand-name companies argue that the 20% variation in absorption rate allowed by the FDA is dangerously arbitrary. Explains Carol Grundfest, manager of scientific services for the Pharmaceutical Manufacturers Association: ''For most drugs, the variability doesn't matter. But we're concerned about the few for which the difference between what is effective and what is toxic is very little.'' Yet the FDA has censured some drug companies for antigeneric campaigns. In 1985 the agency charged Sandoz, maker of Mellaril, an antipsychotic, with ''flagrant, repeated and willful'' violations of advertising regulations and required it to correct assertions that the generic equivalent, thioridazine, causes unpredictable results. Mylan Laboratories, a maker of thioridazine, sued Sandoz last year, alleging false advertising. Sandoz settled out of court for about $1 million.

CHART: Cure for overweight pill prices These four drugs, whose patents recently expired, cost much less in their generi c versions than they do when prescribed by brand name. All prices are for 100 p rescription-strength pills. The mail-order prices are available to members of t he American Association of Retired Persons. As our five- drugstore Chicago surve y shows, comparison shopping can save you plenty.

Price range in Chicago Brand name/ Mail generic name High Low Average order

Valium/ $38.95 $26.99 $33.22 $24.30 diazepam 30.75 9.95 16.12 11.95

Inderal/ 31.95 20.99 26.09 18.40 propranolol 25.50 9.95 15.47 9.95

Aldomet/ 27.25 18.95 21.62 17.95 methyldopa 21.95 10.95 15.16 11.95

Motrin/ 21.50 13.99 17.66 12.95 ibuprofen 16.95 7.45 11.46 9.95

Credit: JAVIER ROMERO