The recognition that inflammatory events in the airways play a key role in the pathogenesis of
asthma has led to a relentless search for pharmacological agents which modify these processes.
Nedocromil sodium (
Tilade) represents one such agent.
Nedocromil sodium, when inhaled by patients with
asthma (0.05-0.50% nebulized, 0.5-4.0 mg m.d.i.), has been shown to inhibit immediate bronchoconstriction provoked by challenges with
allergen (10 studies), exercise (five studies), isocapnic
hyperventilation, fog and sulphur dioxide (one study each) and
adenosine (two studies). With these challenges, inhibition of bronchoconstriction exhibited dose-dependency up to 4 mg, with
nedocromil sodium being up to four times more potent than
sodium cromoglycate. When inhaled prior to
allergen provocation,
nedocromil sodium inhibited the late asthmatic reaction; when taken regularly during the pollen season, it attenuated the
allergen-induced increase in non-specific bronchial responsiveness. The efficacy of
nedocromil sodium (4 mg q.i.d.) in the treatment of clinical
asthma was initially shown in four open studies and subsequently confirmed in nine double-blind, placebo-controlled 4-12 week studies on patients with seasonal and perennial
asthma. Further clinical trials (eight studies) identified some difficulty in replacing inhaled
corticosteroids with
nedocromil sodium, especially if the
corticosteroids were reduced rapidly (four studies). However, two studies have shown that
nedocromil sodium produced further improvement in
asthma symptoms when used in addition to
bronchodilators and inhaled
corticosteroids. Treatment with
nedocromil sodium (4 mg q.i.d.) for up to 52 weeks demonstrated a progressive reduction in
bronchodilator usage throughout the whole treatment period. During clinical assessment,
nedocromil sodium was well tolerated, side-effects being unpleasant taste,
nausea and
headache. In most cases the adverse reactions were mild and transient, although in approximately 3% of patients they resulted in withdrawal from clinical trials. Thus,
nedocromil sodium is a novel
drug of proven efficacy in the treatment of
asthma. Its position in the therapeutic armamentarium is likely to be as an adjunct to
bronchodilators and inhaled
steroids, to produce improvement in symptoms beyond that achieved with the already established drugs.