SEREVENT DISKUS Inhalation powder Ref.[10690] Active ingredients: Salmeterol

5.1 Asthma-Related Death

LABA, such as salmeterol, the active ingredient in SEREVENT DISKUS, as monotherapy (without ICS) increase the risk of asthma-related death. When LABA are used in fixed-dose combination with ICS, data from large clinical trials do not show a significant increase in the risk of serious asthma-related events (hospitalizations, intubations, death) compared with ICS alone.

Use of SEREVENT DISKUS for the treatment of asthma without concomitant use of an ICS is contraindicated. Use SEREVENT DISKUS only as additional therapy for patients with asthma who are currently taking but are inadequately controlled on an ICS. Do not use SEREVENT DISKUS for patients whose asthma is adequately controlled on low- or medium-dose ICS.

Pediatric and Adolescent Patients

Available data from controlled clinical trials suggest that LABA as monotherapy increase the risk of asthma-related hospitalization in pediatric and adolescent patients. For pediatric and adolescent patients with asthma who require addition of a LABA to an ICS, a fixed-dose combination product containing both an ICS and a LABA should ordinarily be used to ensure adherence with both drugs. In cases where use of a separate ICS and a LABA is clinically indicated, appropriate steps must be taken to ensure adherence with both treatment components. If adherence cannot be assured, a fixed-dose combination product containing both an ICS and a LABA is recommended.

The Salmeterol Multicenter Asthma Research Trial (SMART) was a large 28-week placebo-controlled U.S. trial comparing the safety of salmeterol (SEREVENT Inhalation Aerosol) with placebo, each added to usual asthma therapy, that showed an increase in asthma-related deaths in subjects receiving salmeterol [see Clinical Studies (14.1)]. Given the similar basic mechanisms of action of beta₂-agonists, the findings seen in the SMART trial are considered a class effect.

A 16-week clinical trial performed in the United Kingdom, the Salmeterol Nationwide Surveillance (SNS) trial, showed results similar to the SMART trial. In the SNS trial, the rate of asthma-related death was numerically, though not statistically significantly, greater in subjects with asthma treated with salmeterol (42 mcg twice daily) than those treated with albuterol (180 mcg 4 times daily) added to usual asthma therapy.

The SNS and SMART trials enrolled subjects with asthma. Available data do not suggest an increased risk of death with use of LABA in patients with COPD.

5.2 Deterioration of Disease and Acute Episodes

SEREVENT DISKUS should not be initiated in patients during rapidly deteriorating or potentially life-threatening episodes of asthma or COPD. SEREVENT DISKUS has not been studied in subjects with acutely deteriorating asthma or COPD. The initiation of SEREVENT DISKUS in this setting is not appropriate.

Serious acute respiratory events, including fatalities, have been reported when salmeterol has been initiated in patients with significantly worsening or acutely deteriorating asthma. In most cases, these have occurred in patients with severe asthma (e.g., patients with a history of corticosteroid dependence, low pulmonary function, intubation, mechanical ventilation, frequent hospitalizations, previous life-threatening acute asthma exacerbations) and in some patients with acutely deteriorating asthma (e.g., patients with significantly increasing symptoms; increasing need for inhaled, short-acting beta₂-agonists; decreasing response to usual medications; increasing need for systemic corticosteroids; recent emergency room visits; deteriorating lung function). However, these events have occurred in a few patients with less severe asthma as well. It was not possible from these reports to determine whether salmeterol contributed to these events.

Increasing use of inhaled, short-acting beta₂-agonists is a marker of deteriorating asthma. In this situation, the patient requires immediate reevaluation with reassessment of the treatment regimen, giving special consideration to the possible need for adding additional ICS or initiating systemic corticosteroids. Patients should not use more than 1 inhalation twice daily of SEREVENT DISKUS.

SEREVENT DISKUS should not be used for the relief of acute symptoms, i.e., as rescue therapy for the treatment of acute episodes of bronchospasm. An inhaled, short-acting beta₂-agonist, not SEREVENT DISKUS, should be used to relieve acute symptoms such as shortness of breath. When prescribing SEREVENT DISKUS, the healthcare provider should also prescribe an inhaled, short-acting beta₂-agonist (e.g., albuterol) for treatment of acute symptoms.

When beginning treatment with SEREVENT DISKUS, patients who have been taking oral or inhaled, short-acting beta₂-agonists on a regular basis (e.g., 4 times a day) should be instructed to discontinue the regular use of these drugs.

5.3 SEREVENT DISKUS is Not a Substitute for Corticosteroids

There are no data demonstrating that SEREVENT DISKUS has a clinical anti-inflammatory effect such as that associated with corticosteroids. When initiating and throughout treatment with SEREVENT DISKUS in patients receiving oral or ICS for treatment of asthma, patients must continue taking a suitable dosage of corticosteroids to maintain clinical stability even if they feel better as a result of initiating SEREVENT DISKUS. Any change in corticosteroid dosage should be made ONLY after clinical evaluation.

5.4 Excessive Use of SEREVENT DISKUS and Use with Other Long-acting Beta₂-agonists

SEREVENT DISKUS should not be used more often than recommended, at higher doses than recommended, or in conjunction with other medicines containing LABA, as an overdose may result. Clinically significant cardiovascular effects and fatalities have been reported in association with excessive use of inhaled sympathomimetic drugs. Patients using SEREVENT DISKUS should not use another medicine containing a LABA (e.g., formoterol fumarate, arformoterol tartrate, indacaterol) for any reason.

5.5 Paradoxical Bronchospasm and Upper Airway Symptoms

As with other inhaled medicines, SEREVENT DISKUS can produce paradoxical bronchospasm, which may be life threatening. If paradoxical bronchospasm occurs following dosing with SEREVENT DISKUS, it should be treated immediately with an inhaled, short-acting bronchodilator; SEREVENT DISKUS should be discontinued immediately; and alternative therapy should be instituted. Upper airway symptoms of laryngeal spasm, irritation, or swelling, such as stridor and choking, have been reported in patients receiving SEREVENT DISKUS.

5.6 Cardiovascular and Central Nervous System Effects

Excessive beta-adrenergic stimulation has been associated with seizures, angina, hypertension or hypotension, tachycardia with rates up to 200 beats/min, arrhythmias, nervousness, headache, tremor, palpitation, nausea, dizziness, fatigue, malaise, and insomnia [see Overdosage (10)]. Therefore, SEREVENT DISKUS, like all products containing sympathomimetic amines, should be used with caution in patients with cardiovascular disorders, especially coronary insufficiency, cardiac arrhythmias, and hypertension.

Salmeterol can produce a clinically significant cardiovascular effect in some patients as measured by pulse rate, blood pressure, and/or symptoms. Although such effects are uncommon after administration of salmeterol at recommended doses, if they occur, the drug may need to be discontinued. In addition, beta-agonists have been reported to produce electrocardiogram (ECG) changes, such as flattening of the T wave, prolongation of the QTc interval, and ST segment depression. The clinical significance of these findings is unknown. Large doses of inhaled or oral salmeterol (12 to 20 times the recommended dose) have been associated with clinically significant prolongation of the QTc interval, which has the potential for producing ventricular arrhythmias. Fatalities have been reported in association with excessive use of inhaled sympathomimetic drugs.

5.7 Immediate Hypersensitivity Reactions

Immediate hypersensitivity reactions (e.g., urticaria, angioedema, rash, bronchospasm, hypotension), including anaphylaxis, may occur after administration of SEREVENT DISKUS. There have been reports of anaphylactic reactions in patients with severe milk protein allergy after inhalation of powder products containing lactose; therefore, patients with severe milk protein allergy should not use SEREVENT DISKUS [see Contraindications (4)].

5.8 Drug Interactions with Strong Cytochrome P450 3A4 Inhibitors

The use of strong cytochrome P450 3A4 (CYP3A4) inhibitors (e.g., ritonavir, atazanavir, clarithromycin, indinavir, itraconazole, nefazodone, nelfinavir, saquinavir, ketoconazole, telithromycin) with SEREVENT DISKUS is not recommended because increased cardiovascular adverse effects may occur [see Drug Interactions (7.1), Clinical Pharmacology (12.3)].

5.9 Coexisting Conditions

SEREVENT DISKUS, like all medicines containing sympathomimetic amines, should be used with caution in patients with convulsive disorders or thyrotoxicosis and in those who are unusually responsive to sympathomimetic amines. Doses of the related beta₂-adrenoceptor agonist albuterol, when administered intravenously, have been reported to aggravate preexisting diabetes mellitus and ketoacidosis.

5.10 Hypokalemia and Hyperglycemia

Beta-adrenergic agonist medicines may produce significant hypokalemia in some patients, possibly through intracellular shunting, which has the potential to produce adverse cardiovascular effects [see Clinical Pharmacology (12.2)]. The decrease in serum potassium is usually transient, not requiring supplementation. Clinically significant and dose-related changes in blood glucose and/or serum potassium were seen infrequently during clinical trials with SEREVENT DISKUS at recommended doses.

LABA, including salmeterol, the active ingredient in SEREVENT DISKUS, as monotherapy (without ICS) increase the risk of asthma-related death. Data from a large 28-week placebo-controlled U.S. trial that compared the safety of salmeterol or placebo added to usual asthma therapy showed an increase in asthma-related deaths in subjects receiving salmeterol. Available data from controlled clinical trials suggest that LABA as monotherapy increase the risk of asthma-related hospitalization in pediatric and adolescent patients [see Warnings and Precautions (5.1), Clinical Studies (14.1)].

Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared with rates in the clinical trials of another drug and may not reflect the rates observed in practice.

Clinical Trials Experience in Asthma

Adult and Adolescent Subjects Aged 12 Years and Older

Two multicenter, 12-week, placebo-controlled clinical trials evaluated twice-daily doses of SEREVENT DISKUS in subjects aged 12 years and older with asthma. Table 1 reports the incidence of adverse reactions in these 2 trials.

Table 1. Adverse Reactions with SEREVENT DISKUS with ≥3% Incidence and More Common than Placebo in Adult and Adolescent Subjects with Asthma^a:

^a Table 1 includes all events (whether considered drug-related or nondrug-related by the investigator) that occurred at a rate of ≥3% in the group receiving SEREVENT DISKUS and were more common than in the placebo group.

Pharyngitis, sinusitis, upper respiratory tract infection, and cough occurred at ≥3% but were more common in the placebo group. However, throat irritation has been described at rates exceeding that of placebo in other controlled clinical trials.

Additional Adverse Reactions: Other adverse reactions not previously listed, whether considered drug-related or not by the investigators, that were reported more frequently by subjects with asthma treated with SEREVENT DISKUS compared with subjects treated with placebo include the following: contact dermatitis, eczema, localized aches and pains, nausea, oral mucosal abnormality, pain in joint, paresthesia, pyrexia of unknown origin, sinus headache, and sleep disturbance.

Pediatric Subjects Aged 4 to 11 Years

Two multicenter, 12-week, controlled trials have evaluated twice-daily doses of SEREVENT DISKUS in subjects aged 4 to 11 years with asthma. Table 2 includes all events (whether considered drug-related or nondrug-related by the investigator) that occurred at a rate of ≥3% in the group receiving SEREVENT DISKUS and were more common than in the placebo group.

Table 2. Adverse Reaction Incidence in Two 12-Week Pediatric Clinical Trials in Subjects with Asthma:

The following events were reported at an incidence of >1% in the salmeterol group and with a higher incidence than in the albuterol and placebo groups: gastrointestinal signs and symptoms, lower respiratory signs and symptoms, photodermatitis, and arthralgia and articular rheumatism.

In clinical trials evaluating concurrent therapy of salmeterol with ICS, adverse events were consistent with those previously reported for salmeterol, or with events that would be expected with the use of ICS.

Laboratory Test Abnormalities

Elevation of hepatic enzymes was reported in ≥1% of subjects in clinical trials. The elevations were transient and did not lead to discontinuation from the trials. In addition, there were no clinically relevant changes noted in glucose or potassium.

6.2 Clinical Trials Experience in Chronic Obstructive Pulmonary Disease

Two multicenter, 24-week, placebo-controlled U.S. trials evaluated twice-daily doses of SEREVENT DISKUS in subjects with COPD. For presentation (Table 3), the placebo data from a third trial, identical in design, subject entrance criteria, and overall conduct but comparing fluticasone propionate with placebo, were integrated with the placebo data from these 2 trials (total N=341 for salmeterol and 576 for placebo).

Table 3. Adverse Reactions with SEREVENT DISKUS with ≥3% Incidence in U.S. Controlled Clinical Trials in Subjects with Chronic Obstructive Pulmonary Disease ^a:

^a Table 3 includes all events (whether considered drug-related or nondrug-related by the investigator) that occurred at a rate of ≥3% in the group receiving SEREVENT DISKUS and were more common than in the placebo group.

Additional Adverse Reactions

Other adverse reactions occurring in the group receiving SEREVENT DISKUS that occurred at a frequency of ≥1% and were more common than in the placebo group were as follows: anxiety; arthralgia and articular rheumatism; bone and skeletal pain; candidiasis mouth/throat; dental discomfort and pain; dyspeptic symptoms; edema and swelling; gastrointestinal infections; hyperglycemia; hyposalivation; keratitis and conjunctivitis; lower respiratory signs and symptoms; migraines; muscle pain; muscle stiffness, tightness, and rigidity; musculoskeletal inflammation; pain; and skin rashes.

Adverse reactions to salmeterol are similar in nature to those seen with other selective beta₂-adrenoceptor agonists, e.g., tachycardia; palpitations; immediate hypersensitivity reactions, including urticaria, angioedema, rash, bronchospasm; headache; tremor; nervousness; and paradoxical bronchospasm.

Laboratory Abnormalities

There were no clinically relevant changes in these trials. Specifically, no changes in potassium were noted.

In addition to adverse reactions reported from clinical trials, the following adverse reactions have been identified during postapproval use of salmeterol. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure. These events have been chosen for inclusion due to either their seriousness, frequency of reporting, or causal connection to salmeterol or a combination of these factors.

In extensive U.S. and worldwide postmarketing experience with salmeterol, serious exacerbations of asthma, including some that have been fatal, have been reported. In most cases, these have occurred in patients with severe asthma and/or in some patients in whom asthma has been acutely deteriorating [see Warnings and Precautions (5.2)], but they have also occurred in a few patients with less severe asthma. It was not possible from these reports to determine whether salmeterol contributed to these events.

Cardiovascular:

Arrhythmias (including atrial fibrillation, supraventricular tachycardia, extrasystoles) and anaphylaxis.

Non-Site Specific:

Very rare anaphylactic reaction in patients with severe milk protein allergy.

Respiratory:

Reports of upper airway symptoms of laryngeal spasm, irritation, or swelling such as stridor or choking; oropharyngeal irritation.

7.1 Inhibitors of Cytochrome P450 3A4

Salmeterol is a substrate of CYP3A4. The use of strong CYP3A4 inhibitors (e.g., ritonavir, atazanavir, clarithromycin, indinavir, itraconazole, nefazodone, nelfinavir, saquinavir, ketoconazole, telithromycin) with SEREVENT DISKUS is not recommended because increased cardiovascular adverse effects may occur.

In a drug interaction trial in 20 healthy subjects, coadministration of inhaled salmeterol (50 mcg twice daily) and oral ketoconazole (400 mg once daily) for 7 days resulted in greater systemic exposure to salmeterol (AUC increased 16-fold and C_max increased 1.4-fold). Three (3) subjects were withdrawn due to beta₂-agonist side effects (2 with prolonged QTc and 1 with palpitations and sinus tachycardia). Although there was no statistical effect on the mean QTc, coadministration of salmeterol and ketoconazole was associated with more frequent increases in QTc duration compared with salmeterol and placebo administration.

7.2 Monoamine Oxidase Inhibitors and Tricyclic Antidepressants

SEREVENT DISKUS should be administered with extreme caution to patients being treated with monoamine oxidase inhibitors or tricyclic antidepressants, or within 2 weeks of discontinuation of such agents, because the action of salmeterol on the vascular system may be potentiated by these agents.

7.3 Beta-adrenergic Receptor Blocking Agents

Beta-blockers not only block the pulmonary effect of beta-agonists, such as salmeterol, but may also produce severe bronchospasm in patients with asthma or COPD. Therefore, patients with asthma or COPD should not normally be treated with beta-blockers. However, under certain circumstances, there may be no acceptable alternatives to the use of beta-adrenergic blocking agents for these patients; cardioselective beta-blockers could be considered, although they should be administered with caution.

7.4 Non–Potassium-Sparing Diuretics

The ECG changes and/or hypokalemia that may result from the administration of non-potassium-sparing diuretics (such as loop or thiazide diuretics) can be acutely worsened by beta-agonists, especially when the recommended dose of the beta-agonist is exceeded. Although the clinical significance of these effects is not known, caution is advised in the coadministration of SEREVENT DISKUS with non-potassium-sparing diuretics.

Risk Summary

The available data from published epidemiological studies and case reports with use of SEREVENT DISKUS in pregnant women have not identified a drug-associated risk of major birth defects, miscarriage, or adverse maternal or fetal outcomes (see Data). Beta‑agonists may interfere with uterine contractility. There are clinical considerations in pregnant women with asthma (see Clinical Considerations).

Oral administration of salmeterol to pregnant rabbits caused teratogenicity characteristic of beta‑adrenoceptor stimulation at maternal doses approximately 50 times the maximum recommended human daily inhaled dose (MRHDID) on an AUC basis. These adverse effects generally occurred at large multiples of the MRHDID when salmeterol was administered by the oral route to achieve high systemic exposures. No such effects occurred at an oral salmeterol dose approximately 20 times the MRHDID (see Data).

The estimated background risk of major birth defects and miscarriage for the indicated population is unknown. All pregnancies have a background risk of birth defect, loss, or other adverse outcomes. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2% to 4% and 15% to 20%, respectively.

Clinical Considerations

Disease-Associated Maternal and/or Embryofetal Risk

In women with poorly or moderately controlled asthma, there is an increased risk of pre-eclampsia in the mother and prematurity, low birth weight, and small for gestational age in the neonate. Severe asthma during pregnancy has been associated with maternal mortality, fetal mortality, or both. Pregnant women with asthma should be closely monitored and medication adjusted as necessary to maintain optimal asthma control.

Labor and Delivery

There are no adequate and well-controlled human studies that have evaluated the effects of SEREVENT DISKUS during labor and delivery. Because of the potential for beta-agonist interference with uterine contractility, use of SEREVENT DISKUS during labor should be restricted to those patients in whom the benefits clearly outweigh the risks.

Data

Human Data

While available studies cannot definitively establish the absence of risk, published data from epidemiological studies and case reports have not established an association with SEREVENT DISKUS use during pregnancy and major birth defects, miscarriage, or adverse maternal or fetal outcomes. The available studies have methodologic limitations, including retrospective data collection and inconsistent comparator groups.

Animal Data

In 3 embryofetal development studies, pregnant rabbits received oral administration of salmeterol at doses ranging from 100 to 10,000 mcg/kg/day during the period of organogenesis. In pregnant Dutch rabbits administered salmeterol doses approximately 50 times the MRHDID (on an AUC basis at maternal oral doses of 1,000 mcg/kg/day and higher), fetal toxic effects were observed characteristically resulting from beta‑adrenoceptor stimulation. These included precocious eyelid openings, cleft palate, sternebral fusion, limb and paw flexures, and delayed ossification of the frontal cranial bones. No such effects occurred at a salmeterol dose approximately 20 times the MRHDID (on an AUC basis at a maternal oral dose of 600 mcg/kg/day). New Zealand White rabbits were less sensitive since only delayed ossification of the frontal cranial bones was seen at a salmeterol dose approximately 2,000 times the MRHDID (on a mcg/m² basis at a maternal oral dose of 10,000 mcg/kg/day).

In 2 embryofetal development studies, pregnant rats received salmeterol by oral administration at doses ranging from 100 to 10,000 mcg/kg/day during the period of organogenesis. Salmeterol produced no maternal toxicity or embryofetal effects at doses up to 973 times the MRHDID (on a mcg/m² basis at maternal oral doses up to 10,000 mcg/kg/day).

In a peri- and post-natal development study in pregnant rats dosed by the oral route from late gestation through delivery and lactation, salmeterol at a dose 973 times the MRHDID (on a mcg/m² basis with a maternal oral dose of 10,000 mcg/kg/day) was fetotoxic and decreased the fertility of survivors.

Salmeterol xinafoate crossed the placenta following oral administration to mice and rats.

Risk Summary

There is no information regarding the presence of salmeterol in human milk, the effects on the breastfed child, or the effects on milk production. Salmeterol is detected in rat milk (see Data). Salmeterol concentrations in human plasma after inhaled therapeutic doses are low and therefore concentrations in human breast milk are likely to be low [see Clinical Pharmacology (12.3)]. The developmental and health benefits of breastfeeding should be considered along with the mother’s clinical need for SEREVENT DISKUS and any potential adverse effects on the breastfed child from SEREVENT DISKUS or from the underlying maternal condition.

Data

Animal Data

Oral administration of salmeterol at a dose of 10,000 mcg/kg/day to lactating rats resulted in measurable levels in milk.

Available data from controlled clinical trials suggest that LABA used as monotherapy increase the risk of asthma-related hospitalization in pediatric and adolescent patients. For pediatric and adolescent patients with asthma who require addition of a LABA to an ICS, a fixed-dose combination product containing both an ICS and a LABA should ordinarily be used to ensure adherence with both drugs [see Indications and Usage (1.1), Warnings and Precautions (5.1)].

The safety and efficacy of SEREVENT DISKUS in adolescents (aged 12 years and older) have been established based on adequate and well-controlled trials conducted in adults and adolescents [see Clinical Studies (14.1)]. A large 28-week placebo-controlled U.S. trial comparing salmeterol (SEREVENT Inhalation Aerosol) and placebo, each added to usual asthma therapy, showed an increase in asthma-related deaths in subjects receiving salmeterol [see Clinical Studies (14.1)]. Post hoc analyses in pediatric subjects aged 12 to 18 years were also performed. Pediatric subjects accounted for approximately 12% of subjects in each treatment arm. Respiratory-related death or life-threatening experience occurred at a similar rate in the salmeterol group (0.12% [2/1,653]) and the placebo group (0.12% [2/1,622]; relative risk: 1.0 [95% CI: 0.1, 7.2]). All-cause hospitalization, however, was increased in the salmeterol group (2% [35/1,653]) versus the placebo group (less than 1% [16/1,622]; relative risk: 2.1 [95% CI: 1.1, 3.7]).

The safety and efficacy of SEREVENT DISKUS have been evaluated in over 2,500 subjects aged 4 to 11 years with asthma, 346 of whom were administered SEREVENT DISKUS for 1 year. Based on available data, no adjustment of dosage of SEREVENT DISKUS in pediatric patients is warranted for either asthma or EIB.

In 2 randomized, double-blind, controlled clinical trials of 12 weeks' duration, SEREVENT DISKUS 50 mcg was administered to 211 pediatric subjects with asthma who did and who did not receive concurrent ICS. The efficacy of SEREVENT DISKUS was demonstrated over the 12-week treatment period with respect to peak expiratory flow (PEF) and forced expiratory volume in 1 second (FEV₁). SEREVENT DISKUS was effective in demographic subgroups (gender and age) of the population.

In 2 randomized trials in children aged 4 to 11 years with asthma and EIB, a single 50-mcg dose of SEREVENT DISKUS prevented EIB when dosed 30 minutes prior to exercise, with protection lasting up to 11.5 hours in repeat testing following this single dose in many subjects.

Of the total number of adult and adolescent subjects with asthma who received SEREVENT DISKUS in chronic dosing clinical trials, 209 were aged 65 years and older. Of the total number of subjects with COPD who received SEREVENT DISKUS in chronic dosing clinical trials, 167 were aged 65 years and older and 45 were aged 75 years and older. No apparent differences in the safety of SEREVENT DISKUS were observed when geriatric subjects were compared with younger subjects in clinical trials. As with other beta₂-agonists, however, special caution should be observed when using SEREVENT DISKUS in geriatric patients who have concomitant cardiovascular disease that could be adversely affected by beta-agonists. Data from the trials in subjects with COPD suggested a greater effect on FEV₁ of SEREVENT DISKUS in subjects younger than 65 years, as compared with subjects aged 65 years and older. However, based on available data, no adjustment of dosage of SEREVENT DISKUS in geriatric patients is warranted.

Formal pharmacokinetic studies using SEREVENT DISKUS have not been conducted in patients with hepatic impairment. Since salmeterol is predominantly cleared by hepatic metabolism, impairment of liver function may lead to accumulation of salmeterol in plasma. Therefore, patients with hepatic disease should be closely monitored.