Use of drugs as aids in diagnosis is neither new nor uncommon. Therapeutic trials have helped confirm or rule out clinical impressions when accurate methods of detection were not at hand. Colchicine in gout, thyroid in myxedema, quinine in malaria, salicylates in rheumatic fever, neostigmine in myasthenia gravis are some examples. Not long ago, serologic tests with "provocative" arsenicals were used to diagnose latent syphilis. On a higher level of diagnostic sophistication are the more recent uses of hematologic and biochemical responses to loading, stimulation, and suppression with such drugs as tolbutamide, histamine, metyrapone, and β-adrenergic inhibitors. Pharmacodiagnosis is a pharmacologic fringe benefit.
Frohlich et al1 report successful use of β-adrenergic inhibitors, pronethalol and propranolol, in treating, diagnosing, and pinpointing the pathophysiology of a disorder which they are the first— if not to observe—to conceive and designate as the "hyperdynamic beta-adrenergic circulatory state." They describe two patients—one normotensive, the