Albuterol; Ipratropium

What it is

Albuterol with ipratropium is a single inhaler or nebuliser solution containing two drugs that widen the airways by different routes: ipratropium bromide, an inhaled anticholinergic, and albuterol sulfate, an inhaled beta2-agonist. In the US the metered inhaler is sold as Combivent Respimat at 20 micrograms ipratropium with 100 micrograms albuterol per actuation, and a nebuliser solution (often called DuoNeb) is also marketed. It is a prescription medicine, not a nutrient or a supplement, and it is inhaled rather than swallowed.

What the research says

For chronic obstructive pulmonary disease, the combination measurably opens the airways more than either component alone: in the original 85-day trial peak FEV1 rose 31-33 percent with the combination versus 24-27 percent with either single drug, and in the trial supporting the Respimat device the combination beat ipratropium alone by 47 mL of mean FEV1. Symptom scores in that first trial did not differ between groups. In acute asthma attacks treated in an emergency department, adding an inhaled anticholinergic to a beta2-agonist cuts hospital admission (Cochrane: 65 fewer admissions per 1000 adults; number needed to treat 16 in children), but the benefit is confined to severe attacks and disappears once a child is already admitted to a ward. Harms are real and quantified: more adverse events than a beta2-agonist alone (OR 2.03), more cough in long-term use, eye effects and urinary retention from the anticholinergic, and a disputed signal of excess cardiovascular events with inhaled anticholinergics in COPD.

Evidence grade: Well established.

How it works

Drug class: Fixed combination of a short-acting muscarinic antagonist (ipratropium bromide) and a short-acting beta2-adrenergic agonist (albuterol sulfate, called salbutamol outside the US)

Two different bronchodilators in one inhaler. Ipratropium blocks acetylcholine at muscarinic receptors on airway smooth muscle, which removes the nerve signal that keeps airways partly constricted; albuterol stimulates beta2-adrenergic receptors, raising cyclic AMP inside the muscle cell and relaxing it directly. Because they act on different receptors, the manufacturer's stated rationale is that giving both produces more opening of the airway than either at its own dose. (Source 1)

What it is used for

• Randomised trials show the two-drug combination opens the airways more than either drug alone, with the advantage concentrated in the first four hours after a dose. The gain is in lung function; the original trial found no difference in symptom scores between the combination and its components. Evidence: established. (Source 2)
• A Cochrane review of 23 trials found combination inhaled therapy reduced hospitalisation (RR 0.72), equivalent to 65 fewer admissions per 1000 patients, with moderate-quality evidence. The benefit was seen in severe exacerbations but not in mild or moderate ones, and adverse events were about twice as common. Evidence: established. (Source 3)
• A Cochrane review of 20 trials in 2697 children rated the evidence high quality: admission fell from 23 per 100 to 17 per 100, a number needed to treat of 16. Nausea and tremor were less frequent with the combination than with the beta2-agonist alone, and relapse rates did not differ. Evidence: established. (Source 4)
• A separate Cochrane review of trials in children already admitted found no effect on length of hospital stay (mean difference -0.28 hours) and no difference in any secondary marker of response, at moderate-quality evidence. Evidence: not-supported. (Source 5)

Interactions

• Other anticholinergic medicines (for example oxybutynin, tiotropium, some antihistamines) (label): Effects add up, so eye and bladder side effects such as raised eye pressure and urinary retention become more likely. (Source 6)
• Loop and thiazide diuretics (non-potassium-sparing) (label): Both lower potassium and change the ECG; used together the drop in potassium and the ECG changes can be made acutely worse, which is why potassium is sometimes checked. (Source 7)
• Monoamine oxidase inhibitors and tricyclic antidepressants (label): These can amplify albuterol's effect on the heart and blood vessels; the label asks for extreme caution during treatment and for two weeks after stopping them. (Source 8)
• Beta-blockers (including eye drops that contain them) (label): Beta-blockers and albuterol cancel each other out, so the inhaler may work less well and the beta-blocker may provoke wheeze in people with twitchy airways. (Source 9)
• Potassium (serum potassium; potassium supplements are not usually needed) (label): Beta2-agonists can shift potassium into cells and lower the blood level. The label's position is that the fall is usually temporary and does not need a potassium supplement, but it can add to adverse effects on the heart. (Source 10)
• Food, alcohol and dietary supplements generally (label): No food, alcohol or supplement interaction has been formally studied for this inhaled combination. The label says only that the product has been used alongside other COPD drugs and that no formal interaction studies fully evaluated those combinations, so an absence of listed food or supplement interactions here reflects absent research rather than demonstrated safety. (Source 11)

Stopping it

• There is no dependence or withdrawal syndrome described for this inhaler. The label's stopping instruction is event-driven: if the inhaler itself triggers bronchospasm, it should be stopped at once and something else used instead. (Source 12)
• Needing more and more doses is itself a warning sign rather than a reason to keep increasing them: the label records that deaths have been reported with excessive use of inhaled sympathomimetics in asthma. (Source 13)
• Cardiovascular symptoms are also a stopping trigger: the label states that if clinically significant changes in pulse, blood pressure or symptoms occur, the inhaler may need to be discontinued. (Source 14)

What goes wrong

Combination inhaled therapy in adults with acute asthma roughly doubled the odds of an adverse event compared with a beta2-agonist alone. (Source 15)

• Systematic review, Moderate certainty.
• Size: 1392 participants across 11 studies.
• Who: Adults in the emergency department with acute asthma.
• How long: Single emergency department visit.
• Result: OR 2.03 (95% CI 1.28 to 3.20), I-squared 14%; the review names tremor, agitation and palpitations as the events.
• Funding: not stated in the abstract; Cochrane review.

Limit of this finding: The review's own absolute figures for adverse events do not agree with its odds ratio. It prints "103 per 1000 were likely to report adverse events (95% 31 to 195 more) compared to 131 per 1000 patients receiving SABA alone", which read literally says fewer adverse events on the combination - the opposite of the odds ratio of 2.03 and of the review's own conclusion. The intended reading is 103 MORE per 1000 above a baseline of 131 per 1000, and "(95% 31 to 195 more)" is missing the letters "CI". Do not conclude from those two numbers that the combination caused fewer adverse events.

Participants receiving combination inhaled therapy were more likely to experience adverse events than those treated with SABA agents alone (OR 2.03, 95% CI 1.28 to 3.20; participants = 1392; studies = 11; I² = 14%; moderate quality of evidence).

Over 48 weeks of COPD treatment, cough was almost three times as common with the Respimat combination inhaler as with the older aerosol. (Source 16)

• Randomized trial, Low certainty.
• Size: 465 adult COPD patients; 157 on Combivent Respimat.
• Who: Adults 40 years and older with COPD, mean age 62.9 years, mean FEV1 47.0% predicted.
• How long: 48 weeks, open-label, four times daily.
• Result: Cough 7.0% with Combivent Respimat versus 2.6% with CFC-propelled Combivent aerosol and 3.9% with the free combination of ipratropium and albuterol HFA aerosols.
• Funding: industry-funded (Boehringer Ingelheim safety trial reported in the FDA label); open-label design.

However, cough occurred more frequently in patients enrolled in the COMBIVENT RESPIMAT group (7.0%) compared to those in the CFC-propelled COMBIVENT Inhalation Aerosol (2.6%) or the free combination of ipratropium bromide and albuterol HFA inhalation aerosols (3.9%) groups.

A meta-analysis of randomised trials found inhaled anticholinergics in COPD were associated with more cardiovascular deaths, heart attacks and strokes than control, an absolute difference of about 0.7 percentage points. (Source 17)

• Meta-analysis, Low certainty.
• Size: 17 trials enrolling 13,645 patients.
• Who: Patients with COPD in randomised trials of ipratropium or tiotropium lasting at least 30 days.
• How long: Follow-up 6 weeks to 5 years.
• Result: Composite cardiovascular death, MI or stroke in 134 of 6984 (1.9%) on anticholinergics versus 83 of 6661 (1.2%) on control; RR 1.60 (95% CI 1.22-2.10), I-squared 0%; MI RR 1.52 (1.04-2.22); cardiovascular death RR 1.92 (1.23-3.00); stroke not significant RR 1.46 (0.81-2.62)
• Funding: not stated in the abstract; this analysis was later contested and the published figures carry multiple [corrected] markers.

Limit of this finding: The "[corrected]" markers inside this passage are the National Library of Medicine's own published-erratum annotations in the indexed abstract. They are not part of the authors' sentence and not corruption of the quote.

Cardiovascular death, MI, or stroke occurred in 134 of 6984 [corrected] patients (1.9%) [corrected] receiving inhaled anticholinergics and 83 of 6661 [corrected] patients (1.2%) receiving control therapy (RR, 1.60 [corrected] [95% confidence interval {CI}, 1.22-2.10]; [corrected] P < .001, I(2) = 0%). Among individual components of the primary end point, inhaled anticholinergics significantly increased the risk of MI (RR, 1.52 [95% CI 1.04-2.22]; [corrected] P = .03, I(2) = 0%) and cardiovascular death (RR, 1.92 [95% CI, 1.23-3.00]; P = .004, [corrected] I(2) = 0%) without a statistically significant increase in the risk of stroke (RR, 1.46 [95% CI, 0.81-2.62]; P = .20, I(2) = 0%).

In a large cohort of US veterans with newly diagnosed COPD, recent ipratropium exposure was associated with a higher rate of hospitalisation for a cardiovascular event; this is an association, not proof of cause. (Source 18)

• Cohort study, Low certainty.
• Size: 82,717 US veterans; 6,234 cardiovascular events.
• Who: US veterans with a new diagnosis of COPD between 1999 and 2002, followed to September 2004.
• How long: Up to about 5 years.
• Result: Hazard ratio 1.40 (95% CI 1.30-1.51) for up to four 30-day equivalents and 1.23 (1.13-1.36) for more than four, within the past 6 months; no elevated risk when exposure was more than 6 months earlier.
• Funding: not stated in the abstract.

Limit of this finding: The indexed copy of this abstract has mangled the inequality signs - it prints "for< or =four and>four 30-day equivalents". The intended wording is "four or fewer" and "more than four" 30-day equivalents. The hazard ratios themselves are as published.

Compared with subjects not exposed to anticholinergics within the past year, any exposure to anticholinergics within the past 6 months was associated with an increased risk of CVE (hazard ratio [95% CI] for< or =four and>four 30-day equivalents: 1.40 [1.30-1.51] and 1.23 [1.13-1.36], respectively).

The ipratropium component can raise pressure inside the eye and can precipitate or worsen narrow-angle glaucoma, and sprayed into the eye it causes pain, blurring and dilated pupils. (Source 19)

• Official position, Certainty not rated.
• Size: Not applicable - regulator-approved labelling.
• Who: Patients using Combivent Respimat, in particular those with narrow-angle glaucoma.
• How long: Any.
• Result: No rate given; the label requires caution in narrow-angle glaucoma and lists acute eye pain, temporary blurring, mydriasis, visual halos and red eyes after accidental spraying into the eye.
• Funding: Regulatory position (FDA-approved label, DailyMed version published 04 Dec 2025)

Ipratropium bromide, a component of COMBIVENT RESPIMAT, is an anticholinergic and may increase intraocular pressure. This may result in precipitation or worsening of narrow-angle glaucoma.

In a five-year placebo-controlled COPD trial of inhaled ipratropium, 0.5% of patients were hospitalised for supraventricular tachycardia or atrial fibrillation. (Source 20)

• Official position, Certainty not rated.
• Size: Not stated in the label text.
• Who: COPD patients in a 5-year placebo-controlled trial of CFC-propelled ipratropium (Atrovent) inhalation aerosol.
• How long: 5 years.
• Result: Incidence rate 0.5% for hospitalisation for supraventricular tachycardia and/or atrial fibrillation.
• Funding: Reported in the manufacturer's FDA label.

In a 5-year placebo-controlled trial, hospitalizations for supraventricular tachycardia and/or atrial fibrillation occurred with an incidence rate of 0.5% in COPD patients receiving CFC-propelled ATROVENT® (ipratropium bromide) Inhalation Aerosol.

The inhaler can itself cause bronchospasm that can be life-threatening, which is the opposite of its intended effect. (Source 12)

• Official position, Certainty not rated.
• Size: Not applicable - regulator-approved labelling.
• Who: Anyone using the inhaler.
• How long: Any.
• Result: No rate given; the label instructs immediate discontinuation and alternative therapy.
• Funding: Regulatory position (FDA-approved label)

COMBIVENT RESPIMAT can produce paradoxical bronchospasm that can be life-threatening. If it occurs, therapy with COMBIVENT RESPIMAT should be discontinued immediately and alternative therapy instituted.

What the evidence supports

Adding a short-acting inhaled anticholinergic to a short-acting beta2-agonist in adults with acute asthma in the emergency department reduced hospital admission, with an absolute reduction of 65 admissions per 1000. (Source 21)

• Systematic review, Moderate certainty.
• Size: 2724 enrolled participants across 23 studies (2120 across 16 studies for the admission outcome)
• Who: Adults presenting to an emergency department with an asthma exacerbation.
• How long: Single or multiple doses during the emergency department visit.
• Result: RR 0.72 (95% CI 0.59 to 0.87), I-squared 12%; an estimated 65 fewer hospitalisations per 1000 (95% 30 to 95) compared with 231 per 1000 on a beta2-agonist alone.
• Funding: not stated in the abstract; Cochrane review.

Limit of this finding: The review prints this absolute effect as "(95% 30 to 95)", with the letters "CI" missing. Read it as a 95% confidence interval of 30 to 95 fewer hospitalisations per 1000; "95%" is not a result in its own right.

Overall, participants receiving combination inhaled therapy were less likely to be hospitalised (RR 0.72, 95% CI 0.59 to 0.87; participants = 2120; studies = 16; I² = 12%; moderate quality of evidence). An estimated 65 fewer patients per 1000 would require hospitalisation after receiving combination therapy (95% 30 to 95), compared to 231 per 1000 patients receiving SABA alone.

In children with acute asthma in the emergency department, adding an inhaled anticholinergic to a beta2-agonist cut hospital admission from 23 per 100 to 17 per 100, a number needed to treat of 16. (Source 4)

• Systematic review, High certainty.
• Size: 2697 randomised children across 20 trials; 2497 children across 15 studies for the admission outcome.
• Who: Children aged one to 18 years, predominantly moderate or severe exacerbations; nine of 20 trials at low risk of bias.
• How long: Fixed-dose protocols of one to three ipratropium doses over 30 to 90 minutes.
• Result: RR 0.73 (95% CI 0.63 to 0.85); 23 per 100 admitted on beta2-agonist alone versus 17 per 100 (95% CI 15 to 20); NNTB 16 (95% CI 12 to 29)
• Funding: not stated in the abstract; Cochrane review.

The addition of an anticholinergic to a SABA significantly reduced the risk of hospital admission (risk ratio (RR) 0.73; 95% confidence interval (CI) 0.63 to 0.85; 15 studies, 2497 children, high-quality evidence). In the group receiving only SABAs, 23 out of 100 children with acute asthma were admitted to hospital compared with 17 (95% CI 15 to 20) out of 100 children treated with SABAs plus anticholinergics. This represents an overall number needed to treat for an additional beneficial outcome (NNTB) of 16 (95% CI 12 to 29).

In stable moderately severe COPD, the ipratropium plus albuterol combination produced a larger peak rise in FEV1 than either drug alone over 85 days. (Source 2)

• Randomized trial, Moderate certainty.
• Size: 534 patients.
• Who: Patients with moderately severe stable COPD, on background theophylline and corticosteroids as required.
• How long: 12 weeks (85 days), testing on days 1, 29, 57 and 85.
• Result: Mean peak percent increase in FEV1 over baseline 31-33% for the combination versus 24-25% for ipratropium and 24-27% for albuterol; AUC0-4 means 21-44% greater than ipratropium and 30-46% greater than albuterol.
• Funding: not stated; conducted by the COMBIVENT Inhalation Aerosol Study Group (manufacturer-named study group)

The mean peak percent increases in FEV1 over baseline on the four test days were 31 to 33 percent for the combination, 24 to 25 percent for ipratropium, and 24 to 27 percent for albuterol.

In the registration trial for the Respimat device, the combination beat ipratropium alone on early lung function by 47 mL, confirming that the albuterol component contributes measurably. (Source 22)

• Randomized trial, Moderate certainty.
• Size: 1,460 adult COPD patients (1,424 in the efficacy analysis); 486 on Combivent Respimat.
• Who: Adults 40 years and older with COPD, FEV1 at or below 65% predicted, more than 10 pack-years smoking; narrow-angle glaucoma and prostatic hypertrophy excluded.
• How long: 12 weeks, four times daily dosing.
• Result: FEV1 AUC0-4h treatment difference versus ipratropium 47 mL (95% CI 28, 66); FEV1 AUC4-6h difference -17 mL (95% CI -39, 5), i.e. non-inferior not superior; versus the older CFC aerosol the difference was -3 mL (95% CI -22, 15)
• Funding: industry-funded (Boehringer Ingelheim registration trial reported in the FDA label)

The FEV1 AUC0-4h for COMBIVENT RESPIMAT (20/100 mcg), was superior to that of ipratropium bromide [LS mean (mL) (95% CI) of the treatment difference was 47 mL (28, 66)] and the mean FEV1 AUC4-6h for COMBIVENT RESPIMAT (20/100 mcg) was non-inferior to that of ipratropium bromide [LS mean (mL) (95% CI) of the treatment difference was -17 (-39, 5)].

What the evidence does not support

In children already admitted to hospital with acute asthma, continuing ipratropium with a beta2-agonist did not shorten the hospital stay or improve any other measured outcome. (Source 5)

• Systematic review, Moderate certainty.
• Size: 472 children across four trials with usable data (327 participants in three studies for the primary outcome)
• Who: Children one to 18 years admitted to paediatric wards; no trials included intensive-care admissions.
• How long: Ipratropium 250 micrograms every one to eight hours, from four hours up to the whole hospital stay.
• Result: Mean difference in duration of hospital admission -0.28 hours (95% CI -5.07 to 4.52); no significant group difference in supplemental asthma therapy, clinical scores, lung function or withdrawals.
• Funding: not stated in the abstract; Cochrane review.

The addition of anticholinergics to β2-agonists showed no evidence of effect on the duration of hospital admission (mean difference (MD) -0.28 hours, 95% confidence interval (CI) -5.07 to 4.52, 3 studies, 327 participants, moderate quality evidence) and no serious or non-serious adverse events were reported in any included trials.

The emergency-department benefit in adults was limited to severe exacerbations; it was not found in mild or moderate asthma attacks. (Source 21)

• Systematic review, Moderate certainty.
• Size: Subgroup analysis within 23 studies, 2724 participants.
• Who: Adults in the emergency department stratified by exacerbation severity.
• How long: Single visit.
• Result: Test for difference between severity subgroups P = 0.02; no reduction in hospitalisation in mild or moderate exacerbations.
• Funding: not stated in the abstract; Cochrane review.

Limit of this finding: The same paragraph of this review prints its absolute effects without the letters "CI" ("(95% 30 to 95)"). That is a typesetting omission in the review, not a separate result.

Although combination inhaled therapy was more effective than SABA treatment alone in reducing hospitalisation in participants with severe asthma exacerbations, this was not found for participants with mild or moderate exacerbations (test for difference between subgroups P = 0.02).

In the 85-day COPD trial the extra lung function from the combination did not translate into better symptom scores. (Source 2)

• Randomized trial, Moderate certainty.
• Size: 534 patients.
• Who: Moderately severe stable COPD.
• How long: 12 weeks.
• Result: Symptom scores did not change over time and did not differ among the three treatment groups.
• Funding: not stated; COMBIVENT Inhalation Aerosol Study Group.

Symptom scores did not change over time and did not differ among the treatment groups.

Where the research disagrees

Whether inhaled anticholinergics (the ipratropium half of this combination) increase cardiovascular events in COPD

• Singh, Loke and Furberg, meta-analysis of 17 randomised trials, JAMA 2008, meta-analysis of randomised controlled trials: Inhaled anticholinergics are associated with a significantly increased risk of cardiovascular death, MI, or stroke among patients with COPD. (Source 23)
• Rodrigo and colleagues, synthesis of the available evidence, Drugs 2009, narrative-review synthesising later meta-analyses and pooled safety analyses: One meta-analysis found that the risk for major cardiovascular events was higher with anticholinergics compared with placebo or active comparator controls, whereas two subsequent meta-analyses that included new trial data found no difference in risk. (Source 24)

How much

• Reference intake: Dosing is set by the prescriber. As a position, the FDA-approved Combivent Respimat label (DailyMed version published 04 December 2025) states the recommended dosage is one inhalation four times a day. (Source 25)
• Upper limit: As a position, the same FDA label caps the total at six inhalations in 24 hours and states that safety and efficacy beyond that have not been studied. (Source 25)
• Studied: The 85-day COPD trial gave albuterol, ipratropium or the combination by metered-dose inhaler four times daily to 534 patients on stable background theophylline and corticosteroids. (Source 2)
• Studied: The Respimat registration trial compared Combivent Respimat 20/100 micrograms, CFC-propelled Combivent 36/206 micrograms and ipratropium Respimat 20 micrograms, each four times a day for 12 weeks. (Source 22)
• Studied: Paediatric emergency-department trials mostly used three doses of 250 micrograms or two doses of 500 micrograms of nebulised ipratropium with a short-acting beta2-agonist over 30 to 90 minutes. (Source 4)

A common belief, and what the research shows

The belief: If two bronchodilators are better than one, the combination must help in every situation where one is used.

What the research shows: The evidence is use-specific. In adults with acute asthma in the emergency department the Cochrane review states the benefit was confined to severe attacks: this was not found for participants with mild or moderate exacerbations (test for difference between subgroups P = 0.02). And once children are already admitted to a ward, the separate Cochrane review reports: no evidence of effect on the duration of hospital admission (mean difference (MD) -0.28 hours, 95% confidence interval (CI) -5.07 to 4.52, 3 studies, 327 participants, moderate quality evidence)

Questions and answers

What is it?

It is a prescription inhaler (or nebuliser solution) holding two airway-opening drugs at once: ipratropium bromide, an anticholinergic, and albuterol sulfate, a beta2-agonist. In the US the metered inhaler is Combivent Respimat. It is approved for people with COPD who are already on a regular bronchodilator and still have bronchospasm. (Source 26)

What does it do in the body?

Both components relax the muscle around the airways, but through different receptors: ipratropium blocks acetylcholine at muscarinic receptors, albuterol stimulates beta2 receptors. Giving both is intended to open the airway more than either drug alone at its usual dose. The manufacturer's stated explanation is a local effect on muscarinic and beta2 receptors in the lung. (Source 1)

Is it good or bad for you?

It depends entirely on the setting. In COPD and in severe acute asthma attacks the benefit is measurable: a Cochrane review of 23 adult emergency-department trials found 65 fewer hospitalisations per 1000. In the same review, adverse events were about twice as frequent as with a beta2-agonist alone, so the trade-off is real and should be judged per situation rather than in general. (Source 27)

How do you get more of it?

This is not something a person obtains more of from diet or shops; it is a prescription-only inhaled medicine and the amount delivered is fixed by the device. As a position, the FDA label's recommended dosage is one inhalation four times a day, and more than six inhalations in 24 hours has not been studied. (Source 25)

If it is harmful, what reduces it?

Because it is inhaled and short-acting, the effect fades within hours of the last dose; there is no procedure to clear it from the body. Where it is causing harm the documented action is to stop it. The clearest example is paradoxical bronchospasm, where the label instructs immediate discontinuation and a switch to another treatment. (Source 12)

Why might someone be low in it or missing it?

Someone with COPD may not be on it because it is positioned as a second bronchodilator for people who still have bronchospasm on a regular bronchodilator, not as a first step. It is also avoided or used cautiously in narrow-angle glaucoma, prostate enlargement or bladder-neck obstruction, and patients with those conditions were excluded from the registration trial. (Source 22)

Which whole foods contain it or feed it?

No whole food contains ipratropium or albuterol, and no food or supplement interaction has been formally studied for this inhaler. The one dietary-adjacent issue is potassium: beta2-agonists can shift potassium into cells and lower the blood level, though the label's position is that the fall is usually transient and does not need supplementation. (Source 10)

What happens if you do not have it?

Nothing is missing from the body if a person does not take it; the consequence is the untreated condition. In COPD the trial evidence is about lung function rather than survival: without the combination, FEV1 after a dose is lower, with peak increases of 24 to 27 percent on a single agent against 31 to 33 percent on the combination. (Source 2)

How can you test for it?

There is no blood test for this medicine in normal care. What is measured is the response: spirometry, specifically FEV1 before and after a dose, is the outcome the trials used, with the registration trial defining onset of bronchodilation as an FEV1 rise of 15 percent or more from the test-day baseline. Spirometry is operator- and effort-dependent, so single readings vary. (Source 22)

References

1. DailyMed / US National Library of Medicine (FDA label). COMBIVENT RESPIMAT (ipratropium bromide and albuterol) inhalation spray - FDA prescribing information (Structured Product Label), Boehringer Ingelheim Pharmaceuticals, Inc. - section: 12.1 Mechanism of Action. 2025. Read the source
2. Chest. In chronic obstructive pulmonary disease, a combination of ipratropium and albuterol is more effective than either agent alone. An 85-day multicenter trial. COMBIVENT Inhalation Aerosol Study Group. - section: Abstract. 1994. PMID 8181328, DOI 10.1378/chest.105.5.1411. Read the source
3. The Cochrane database of systematic reviews. Combined inhaled beta-agonist and anticholinergic agents for emergency management in adults with asthma. - section: Main results (first paragraph: studies included and risk of bias). 2017. PMID 28076656, DOI 10.1002/14651858.cd001284.pub2. Read the source
4. The Cochrane database of systematic reviews. Combined inhaled anticholinergics and short-acting beta2-agonists for initial treatment of acute asthma in children. - section: Main results. 2013. PMID 23966133, DOI 10.1002/14651858.cd000060.pub2. Read the source
5. The Cochrane database of systematic reviews. Inhaled anticholinergics and short-acting beta(2)-agonists versus short-acting beta2-agonists alone for children with acute asthma in hospital. - section: Main results. 2014. PMID 25080126, DOI 10.1002/14651858.cd010283.pub2. Read the source
6. DailyMed / US National Library of Medicine (FDA label). COMBIVENT RESPIMAT (ipratropium bromide and albuterol) inhalation spray - FDA prescribing information (Structured Product Label), Boehringer Ingelheim Pharmaceuticals, Inc. - section: 7.1 Anticholinergic Agents. 2025. Read the source
7. DailyMed / US National Library of Medicine (FDA label). COMBIVENT RESPIMAT (ipratropium bromide and albuterol) inhalation spray - FDA prescribing information (Structured Product Label), Boehringer Ingelheim Pharmaceuticals, Inc. - section: 7.4 Diuretics. 2025. Read the source
8. DailyMed / US National Library of Medicine (FDA label). COMBIVENT RESPIMAT (ipratropium bromide and albuterol) inhalation spray - FDA prescribing information (Structured Product Label), Boehringer Ingelheim Pharmaceuticals, Inc. - section: 7.5 Monoamine Oxidase Inhibitors or Tricyclic Antidepressants. 2025. Read the source
9. DailyMed / US National Library of Medicine (FDA label). COMBIVENT RESPIMAT (ipratropium bromide and albuterol) inhalation spray - FDA prescribing information (Structured Product Label), Boehringer Ingelheim Pharmaceuticals, Inc. - section: 7.3 Beta-receptor Blocking Agents. 2025. Read the source
10. DailyMed / US National Library of Medicine (FDA label). COMBIVENT RESPIMAT (ipratropium bromide and albuterol) inhalation spray - FDA prescribing information (Structured Product Label), Boehringer Ingelheim Pharmaceuticals, Inc. - section: 5.8 Hypokalemia. 2025. Read the source
11. DailyMed / US National Library of Medicine (FDA label). COMBIVENT RESPIMAT (ipratropium bromide and albuterol) inhalation spray - FDA prescribing information (Structured Product Label), Boehringer Ingelheim Pharmaceuticals, Inc. - section: 7 DRUG INTERACTIONS (body text). 2025. Read the source
12. DailyMed / US National Library of Medicine (FDA label). COMBIVENT RESPIMAT (ipratropium bromide and albuterol) inhalation spray - FDA prescribing information (Structured Product Label), Boehringer Ingelheim Pharmaceuticals, Inc. - section: 5.1 Paradoxical Bronchospasm. 2025. Read the source
13. DailyMed / US National Library of Medicine (FDA label). COMBIVENT RESPIMAT (ipratropium bromide and albuterol) inhalation spray - FDA prescribing information (Structured Product Label), Boehringer Ingelheim Pharmaceuticals, Inc. - section: 5.5 Do Not Exceed Recommended Dosage. 2025. Read the source
14. DailyMed / US National Library of Medicine (FDA label). COMBIVENT RESPIMAT (ipratropium bromide and albuterol) inhalation spray - FDA prescribing information (Structured Product Label), Boehringer Ingelheim Pharmaceuticals, Inc. - section: 5.2 Cardiovascular Effects. 2025. Read the source
15. The Cochrane database of systematic reviews. Combined inhaled beta-agonist and anticholinergic agents for emergency management in adults with asthma. - section: Main results (fourth paragraph: adverse events). 2017. PMID 28076656, DOI 10.1002/14651858.cd001284.pub2. Read the source
16. DailyMed / US National Library of Medicine (FDA label). COMBIVENT RESPIMAT (ipratropium bromide and albuterol) inhalation spray - FDA prescribing information (Structured Product Label), Boehringer Ingelheim Pharmaceuticals, Inc. - section: 6.1 Clinical Trials Experience - COMBIVENT RESPIMAT Long-Term (48-week) Safety Trial. 2025. Read the source
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