Abstract

Cough is at once a necessary function and an unwanted symptom. Whether preparations intended to prevent it or relieve its discomfort are clinically effective in safe doses is uncertain. This is due to difficulties in experimental method. Neither animal experiments nor experiments with artificially induced cough in man can reliably predict the clinical value of an antitussive,^{1 2} and patients with established cough are poor witnesses of its frequency or severity.^{1 3}