OBJECTIVE: The clinical pharmacology, pharmacokinetics, clinical effic
acy, and adverse effects of the long-acting beta(2)-agonist salmeterol
are reviewed. DATA SOURCES: A MEDLINE search was performed to identif
y English-language publications pertaining to salmeterol. STUDY SELECT
ION: Open and controlled trials were reviewed in assessing clinical ef
ficacy. Only the results of controlled, randomized trials were conside
red in the effectiveness evaluation. DATA EXTRACTION: The primary meas
ures of effectiveness in the clinical trials were bronchodilator activ
ity and reduction of hyperresponsiveness that may reflect antiinflamma
tory activity. Bronchodilator activity was measured as changes in pulm
onary function; reduction of hyperresponsiveness was evaluated using r
espiratory challenge with methacholine, histamine, allergen, or cold a
ir. Secondary measures included symptom scores, need for rescue doses,
and patient preference. DATA SYNTHESIS: Salmeterol is a selective, be
ta(2)-agonist that has been studied in the treatment of exercise-induc
ed, nocturnal, and allergen-induced asthma Salmeterol interacts with t
he traditional beta-receptor in a similar manner as other beta-agonist
s, and it exhibits potent in vivo antiinflammatory effects as an inhib
itor of inflammatory mediator release. Less evidence exists for its in
vivo antiinflammatory activity. Salmeterol demonstrates prolonged rec
eptor occupancy, which is thought to contribute to its long duration o
f action. The recommended dose is 50 mu g via metered-dose inhaler or
dry-powdered inhalation. In the published clinical trials, salmeterol
was more effective than albuterol in treating asthma, including exerci
se and allergen-induced asthma. Salmeterol's major advantage over othe
r inhaled beta-agonists is its long duration of action (12 hours), mak
ing it an excellent choice for treatment of nocturnal asthma. A potent
ial disadvantage is delayed onset of action. Tachyphylaxis to salmeter
ol's bronchodilator effects has not been shown, but tolerance to its p
rotective effects against methacholine-induced bronchoconstriction has
occurred. Adverse effects reported have been mild and have included h
eadache, tremor, and palpitations.