Even though synthetically produced racemic glau-cine has been shown to be an effective, nonnarcotic, centrally acting antitussive drug, it is only available, to our knowledge, in some eastern European countries. Readers should be cautioned that the drug marketed in Europe by the trade name, Glaucine, is not the same drug, and it should not be prescribed as an antitussive; it is a (3-adrenergic blocker, metipra-nolol.
Drugs that May Increase the Threshold or Latency of the Efferent Limb
Aerosolized ipratropium bromide, an atropine-like drug, has been shown to be effective in patients with chronic bronchitis. It may exert its antitussive effect on the efferent limb or on the cough receptor by altering mucociliary factors.
Drugs that May Decrease the Strength of Contraction of the Respiratory Skeletal Muscles
Although they have not been studied as antitussive agents, neuromuscular blocking agents can be classified in this section; they should only be considered for patients with uncontrollable spasms of coughing who are “bucking the ventilator” or could be immediately placed on mechanical ventilatory support. A study on artificially induced cough in normal volunteers suggests that narcotics may exert some of their antitussive effect by decreasing the intensity of contraction of the abdominal muscles; this effect was measured using the integrated abdominal electromyogram.