Drug & supplement interaction

N-acetyl Cysteine (nac) + Salmeterol

Salmeterol brand name: Serevent.

No Known Interaction

Medically reviewed by Dr. Brian Staiger, PharmD, BCPS · Updated July 2026 · Pair last verified Sep 20, 2026

The bottom line No known interaction

We found no known interaction between N-acetyl Cysteine (nac) and Salmeterol in our sources. Absence of a documented interaction is not the same as proven safety, and does not guarantee one does not exist. Do not start, stop, or change a medication or supplement based on this page; confirm with your pharmacist or doctor first. Additionally, although there is no interaction, the label for Salmeterol states a food rule worth keeping to, and the two are separately associated with some of the same side effects, which would make a new symptom harder to attribute to one or the other.

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Interaction report

N-acetyl Cysteine (nac) and Salmeterol

We checked these two against our interaction database. Here is what we found.

No Known Interaction Found

We did not find a documented interaction between Salmeterol and N-acetyl Cysteine (nac) in our sources. This does not guarantee that the combination is completely free of risk — there is often limited research on supplements and herbal products, especially around drug interactions.

If you decide to take both, the practical routine is simple: add one new thing at a time and note the date you started it. If the combination is going to disagree with you, it usually shows in the first days to a couple of weeks — and a start date turns “I’ve been feeling off” into something a pharmacist can actually work with. Do not stop a prescribed medicine on your own.

Always talk with your pharmacist or doctor before making changes to your medications or supplements, particularly if you take several medications or have an ongoing health condition.

N-acetyl Cysteine (nac) safety at a glance

N-acetyl Cysteine... overall Use caution Generally well tolerated at typical doses, but talk to a healthcare provider before use.

Pregnancy Possibly Safe When used orally, intratracheally, intravenously, or by inhalation. N-acetyl cysteine crosses the placenta, but has not been associated with adverse effects to... Read the full pregnancy detail

Breastfeeding Use caution There is not enough reliable safety information, so caution is advised.

Pregnancy & breastfeeding ratings are from Natural Medicines (Therapeutic Research Center) — the full detail is in the Special populations card below. Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

Pharmacist analysis

N-acetyl cysteine (NAC) has a number of potential interactions with several types of drugs.

This includes:

Activated charcoal
Anticoagulant/antiplatelet drugs
Antihypertensive drugs
Chloroquine
Nitroglycerin

All of these interactions are explained in detail on our individual drug-herbal interactions pages.

While there are no known interactions between NAC and the drug in this interaction inquiry, it is important to note that there simply may have a lack of studies to better understand potential issues.

Always let your doctor know about all the drugs and supplements you are taking.

— Dr. Brian Staiger, PharmD, BCPS

Still wondering about combining Salmeterol and N-acetyl Cysteine (nac)? Ask Dr. Brian Staiger, PharmD, BCPS directly ›

How we checked

Why No Interaction Is Listed for Salmeterol

Interactions in our licensed database are recorded against drug classes, not just single drug names. Salmeterol is filed under 3 classifications — beta-adrenergic agonists, qt interval-prolonging drugs, cytochrome p450 3a4 (cyp3a4) substrates. N-acetyl Cysteine (nac) has documented interactions with 5 drug classes — the most serious being nitroglycerin (major), activated charcoal (moderate) and anticoagulant/antiplatelet drugs (moderate) — and none of Salmeterol’s classifications are among them.

Classification data comes from our licensed Natural Medicines dataset. A medication can belong to classes beyond those recorded there, so this describes how the check was run — it is not a safety guarantee.

Keep it in perspective

N-acetyl Cysteine (nac) Does Interact With Other Medications

N-acetyl Cysteine (nac) has 1 major, 293 moderate known drug interactions in our database — Salmeterol isn’t one of them. If you take anything else, check it against the full list below.

Major 1 Moderate 293 No known interaction 2,536 (incl. Salmeterol)

Taking anything else?

Check Another of Your Medications Against N-acetyl Cysteine (nac)

Covers the 2,830 medications we’ve checked against N-acetyl Cysteine (nac). Pick one to open its full report.

What to actually watch for

No Interaction Found — But Data Suggests N-acetyl Cysteine (nac) and Salmeterol May Share Several of the Same Side Effects

This is not an interaction. Neither one changes how your body handles the other, and nothing here says they react together. What our sources do show is that each has separately been linked to the effects below — so taking both can make those effects more likely to turn up, and harder to pin on one or the other if they do. One of them is worth acting on rather than waiting out — marked below.

Wheezing Worth acting on reported in 15.2% of FDA reports for Salmeterol Additional detail
N-acetyl Cysteine (nac)
“Respiratory adverse reactions to N-acetyl cysteine are most commonly reported with inhalable dosage forms. These include wheezing, bronchospasm, and cough. While less frequent, wheezing, bronchospasm, increased sputum production, cough, decreased peak flow, dyspnea, and cold symptoms have been reported with oral N-acetyl cysteine in clinical research.”

N-acetyl Cysteine (nac) · Natural Medicines adverse-effect record, reported in common cold.
6 sources cited

64455. BERNSTEIN, I. L. and AUSDENMOORE, R. W. IATROGENIC BRONCHOSPASM OCCURRING DURING CLINICAL TRIALS OF A NEW MUCOLYTIC AGENT, ACETYLCYSTEINE. Dis.Chest 1964;46:469-473. PubMed

64707. Millman, M. and Grundon, W. Use of acetylcysteine in bronchial asthma and emphysema. J Asthma Res 1969;6(4):199-209. PubMed

64699. Dano, G. Bronchospasm caused by acetylcysteine in children with bronchial asthma. Acta Allergol. 1971;26(3):181-190. DOI

64456. REAS, H. W. THE USE OF N-ACETYLCYSTEINE IN THE TREATMENT OF CYSTIC FIBROSIS. J Pediatr 1964;65:542-557. PubMed

64703. Howatt, W. F. and DeMuth, G. R. A double-blind study of the use of acetylcysteine in patients with cystic fibrosis. Univ Mich.Med Cent.J 1966;32(2):82-85.

64811. Kory, R. C., Hirsch, S. R., and Giraldo, J. Nebulization of N-acetylcysteine combined with a bronchodilator in patients with chronic bronchitis. A controlled study. Chest 1968;54(6):504-509. PubMed
Salmeterol

Listed in the ADVERSE REACTIONS section of the FDA label for Salmeterol, and in voluntary FDA adverse-event reports. Read the label on DailyMed ›
Cough reported in 7.3% of FDA reports for Salmeterol Additional detail

N-acetyl Cysteine (nac)

Recorded for N-acetyl Cysteine (nac) in the same Natural Medicines adverse-effect record shown under Wheezing above.

Salmeterol

Listed in the ADVERSE REACTIONS section of the FDA label for Salmeterol, and in voluntary FDA adverse-event reports. Read the label on DailyMed ›
Sore throat Additional detail
N-acetyl Cysteine (nac)
“Orally, gastrointestinal complaints are the most common adverse effects reported with N-acetyl cysteine. These include heartburn, dyspepsia, and epigastric pain. In one case report, esophagitis related to ulcerations occurred following intake of N-acetyl cysteine while in the supine position with inadequate water.”

N-acetyl Cysteine (nac) · Natural Medicines adverse-effect record, reported in constipation.
6 sources cited

64608. Berk, M., Copolov, D. L., Dean, O., Lu, K., Jeavons, S., Schapkaitz, I., Anderson-Hunt, M., and Bush, A. I. N-acetyl cysteine for depressive symptoms in bipolar disorder--a double-blind randomized placebo-controlled trial. Biol Psychiatry 9-15-2008;64(6) PubMed

64715. Tattersall, A. B., Bridgman, K. M., and Huitson, A. Irish general practice study of acetylcysteine (Fabrol) in chronic bronchitis. J Int Med Res 1984;12(2):96-101. PubMed

64717. Jackson, I. M., Barnes, J., and Cooksey, P. Efficacy and tolerability of oral acetylcysteine (Fabrol) in chronic bronchitis: a double-blind placebo controlled study. J Int Med Res 1984;12(3):198-206. PubMed

64738. Aylward, M., Maddock, J., and Dewland, P. Clinical evaluation of acetylcysteine in the treatment of patients with chronic obstructive bronchitis: a balanced double-blind trial with placebo control. Eur.J Respir.Dis.Suppl 1980;111:81-89.

64739. Long-term oral acetylcysteine in chronic bronchitis. a double-blind controlled study. Eur.J Respir.Dis.Suppl 1980;111:93-108.

102666. Gray KM, Carpenter MJ, Baker NL, et al. A double-blind randomized controlled trial of N-acetylcysteine in cannabis-dependent adolescents. Am J Psychiatry. 2012;169(8):805-12.
Salmeterol

Listed in the ADVERSE REACTIONS section of the FDA label for Salmeterol. Read the label on DailyMed ›
Headache Additional detail
N-acetyl Cysteine (nac)
“Orally, headache has been frequently reported with N-acetyl cysteine in clinical research. Other less common adverse effects reported in patients taking oral N-acetyl cysteine at a total daily dose of 600-1200 mg include dizziness, tiredness, vivid dreams, disorientation, and inability to concentrate.”

N-acetyl Cysteine (nac) · Natural Medicines adverse-effect record, reported in amyotrophic lateral sclerosis (als, lou gehrig's disease).
6 sources cited

7873. Estensen RD, Levy M, Klopp SJ, et al. N-acetylcysteine suppression of the proliferative index in the colon of patients with previous adenomatous colonic polyps. Cancer Lett 1999;147:109-14. PubMed

11430. Oldemeyer JB, Biddle WP, Wurdeman RL, et al. Acetylcysteine in the prevention of contrast-induced nephropathy after coronary angiography. Am Heart J 2003;146:E23. . PubMed

64510. Tirouvanziam, R., Conrad, C. K., Bottiglieri, T., Herzenberg, L. A., Moss, R. B., and Herzenberg, L. A. High-dose oral N-acetylcysteine, a glutathione prodrug, modulates inflammation in cystic fibrosis. Proc Natl.Acad.Sci U.S.A 3-21-2006;103(12):4628-463

64608. Berk, M., Copolov, D. L., Dean, O., Lu, K., Jeavons, S., Schapkaitz, I., Anderson-Hunt, M., and Bush, A. I. N-acetyl cysteine for depressive symptoms in bipolar disorder--a double-blind randomized placebo-controlled trial. Biol Psychiatry 9-15-2008;64(6) PubMed

64672. Rasmussen, J. B. and Glennow, C. Reduction in days of illness after long-term treatment with N-acetylcysteine controlled-release tablets in patients with chronic bronchitis. Eur.Respir.J 1988;1(4):351-355. DOI

64713. Miller, L. F. and Rumack, B. H. Clinical safety of high oral doses of acetylcysteine. Semin.Oncol 1983;10(1 Suppl 1):76-85.
Salmeterol

Listed in the ADVERSE REACTIONS section of the FDA label for Salmeterol. Read the label on DailyMed ›

Reported for N-acetyl Cysteine (nac) but not commonly for Salmeterol: a heart attack, stomach upset, seizures and a slow heartbeat.

Effects for Salmeterol come from the ADVERSE REACTIONS section of its FDA label; effects for N-acetyl Cysteine (nac) come from the Natural Medicines adverse-effect record, quoted above. Where a percentage is shown, it is the share of 107,431 voluntary FDA FAERS reports for Salmeterol that mention that effect — a reporting proportion, not an incidence rate and not evidence the drug caused it. Wording is matched across sources by our own clinical vocabulary, so treat this as a prompt to pay attention, not a diagnosis.

Special populations

N-acetyl Cysteine (nac) in Pregnancy & Breastfeeding

Pregnancy Possibly Safe

When used orally, intratracheally, intravenously, or by inhalation. N-acetyl cysteine crosses the placenta, but has not been associated with adverse effects to the fetus. However, N-acetyl cysteine should only be used in pregnancy when clearly indicated, such as in cases of acetaminophen toxicity.

DISCLAIMER: This tool is intended for informational purposes only, and should not be interpreted as specific medical advice. Patients should consult with a qualified healthcare provider before making decisions about therapies and/or health conditions.© 2026 Therapeutic Research Center

How to take them

Some Salmeterol Products Have a Food Rule — N-acetyl Cysteine (nac) Should Not Break It

At least one FDA label for a product containing Salmeterol says to take it on an empty stomach. Most supplements — N-acetyl Cysteine (nac) included — are taken with a meal, so the easy mistake is swallowing both together at breakfast. Where that rule applies, keep Salmeterol on its own and move N-acetyl Cysteine (nac) to a meal later in the day.

This may not be true of your version. Food instructions belong to the product, not the ingredient: two Salmeterol products can carry different directions, and extended-release forms often differ from immediate-release ones. The label we read is quoted below — check the directions on your own box or bottle, or ask your pharmacist, for how to take the exact product you were given.

One inhalation of SEREVENT DISKUS at least 30 minutes before exercise has been shown to protect patients against EIB.

From the Dosage and Administration section of the FDA label we read for Salmeterol — where that label names a specific product, the instruction is that product's. Read the label on DailyMed ›

A food rule is not an interaction — it is about how much of the medicine you absorb. The directions that came with your own product, and your pharmacist, outrank anything on this page.

Overlapping uses

What Salmeterol Is Prescribed For, and What N-acetyl Cysteine (nac) Has Been Studied For

These two come up together because they touch the same health topic — not because they do the same job. Salmeterol is a prescription medicine with approved uses on its FDA label. N-acetyl Cysteine (nac) is a supplement: what follows is what researchers have looked at it for, and how strong that evidence is.

Salmeterol is prescribed for: Serevent Diskus (salmeterol inhalation powder) is used for three main purposes: treating asthma in patients aged 4 and older when used alongside an inhaled corticosteroid (ICS), preventing exercise-induced bronchospasm (EIB) in patients aged 4 and older, and maintaining treatment of bronchospasm in adults with COPD — including chronic bronchitis and emphysema. Important: Serevent Diskus is not a rescue inhaler. It will not relieve sudden breathing problems. For asthma treatment, it must always be used together with an inhaled corticosteroid — never alone.

N-acetyl Cysteine (nac) has been studied for:

Bronchitis Natural Medicines rates the evidence for N-acetyl Cysteine (nac): Possibly Effective Read what the research shows

N-acetyl Cysteine (nac) for bronchitis

Via inhalation, N-acetyl cysteine is FDA-approved for managing acute episodes of bronchitis. Oral N-acetyl cysteine may help to reduce the occurrence of acute exacerbations of chronic bronchitis when used for 3-36 months.

Effectiveness ratings and the research summaries above are the verbatim record from the Natural Medicines database, which grades evidence from “Effective” down to “Insufficient Reliable Evidence To Rate”. A rating below the top of that scale means researchers have looked at it — not that it works, and never that it can stand in for a prescribed medicine. Do not stop or replace Salmeterol on your own; if you are taking N-acetyl Cysteine (nac) for the same health topic, tell your prescriber, especially if the medicine is being adjusted to a target.

Everything else you take

See Every Supplement That Interacts With Salmeterol

This page covers N-acetyl Cysteine (nac) only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Salmeterol page lists 141 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: American Hellebore (major), Arsenic (major), Cesium (major), Ephedra (major) and Grapefruit (major).

By severity: 7 major · 105 moderate · 29 minor.

From our pharmacist’s overview on the Salmeterol page

“Salmeterol (Serevent) is the long-acting inhaler taken twice daily for asthma or COPD, and its supplement list is one I would approach with real caution. Seven of the 141 ingredients on file rate major: grapefruit can raise salmeterol levels by blocking the enzyme that clears it, St.”

Reviewed by 2 · Jul 18, 2026

Open the Salmeterol interaction page

One more smart check

Taking N-acetyl Cysteine (nac) as Part of a Dietary Supplement Product? Check It for Interactions

We hold 3,554 real supplement products containing N-acetyl Cysteine (nac), each one broken down to its full ingredient list — and combination products often carry several ingredients besides N-acetyl Cysteine (nac). Even though N-acetyl Cysteine (nac) itself has no known interaction with Salmeterol, another ingredient on your label might. Find your product and we’ll check every ingredient on its label:

How much people look this up

Where N-acetyl Cysteine (nac) and Salmeterol Sit Against Everything Else

Out of every supplement and medication people look up on HelloPharmacist, here is where these two land this week — and which way each has been moving.

Supplement N-acetyl Cysteine (nac)

Top 5%

#62 of 1,452 supplements looked up here in the last 7 days

29 days ago today

Medication Salmeterol

Top half

#1,215 of 2,830 medications looked up here in the last 7 days

29 days ago today

Position among everything looked up on this site, not a measure of how commonly either one is used or how important it is. A supplement can climb this list because of a news story. It counts every request to the page, automated ones included, and nothing here identifies anyone.

Where does our data come from?

Source: the Natural Medicines (TRC Healthcare) clinical database — the evidence-graded professional reference for herb & supplement interactions.
Citation library: 103,510 references behind our interaction content, 65,311 of them resolved to verified PubMed/DOI sources. See every N-acetyl Cysteine (nac) reference on this page ↓
Freshness: we automatically re-check this combination every week — this pair was last verified September 20, 2026. The N-acetyl Cysteine (nac) and Salmeterol records this page draws on were last updated July 11, 2026.
What “no known interaction” means: no documented interaction in the sources above — not a guarantee of safety. Supplements are studied far less than prescription drugs, so we say exactly what the evidence supports, and nothing more.

Data structure & sourcing designed and verified by Dr. Brian Staiger, PharmD, BCPS.

Supplement

About N-acetyl Cysteine (nac)

What is N-acetyl Cysteine (nac)?

Thinning mucus in lung conditions
Acetaminophen (Tylenol) overdose treatment
Antioxidant and glutathione support
Liver support
Respiratory health

N-acetyl cysteine (NAC) is a supplement form of the amino acid cysteine and a building block for the antioxidant glutathione. It has well-established prescription uses for acetaminophen overdose and thinning mucus, but evidence for many over-the-counter uses is still limited. It is generally well tolerated, but you should check with a pharmacist or doctor before starting it.

Not applicable (a modified form of the amino acid cysteine) · Capsules, tablets, powder, effervescent tablets, and prescription inhalation or injectable solutions

An interaction check asks whether these two react with each other — it does not ask whether N-acetyl Cysteine (nac) is a good idea for someone in your situation. Here is what our N-acetyl Cysteine (nac) record says about it on its own.

N-acetyl Cysteine (nac): dosing

There is no single standardized dose of NAC for general supplement use, and the right amount depends on why it is being used. Prescription uses, such as treating acetaminophen overdose, follow strict medical protocols and are handled only in a healthcare setting.For over-the-counter supplements, follow the directions on the product label and do not exceed the recommended amount.

From our N-acetyl Cysteine (nac) monograph — the full record covers uses, side effects and every documented interaction.

Read the full N-acetyl Cysteine (nac) monograph & all interactions

Medication

About Salmeterol Oral Inhalation

What Is Salmeterol Oral Inhalation Used For?

Brand name: Serevent

Serevent Diskus (salmeterol inhalation powder) is used for three main purposes: treating asthma in patients aged 4 and older when used alongside an inhaled corticosteroid (ICS), preventing exercise-induced bronchospasm (EIB) in patients aged 4 and older, and maintaining treatment of bronchospasm in adults with COPD — including chronic bronchitis and emphysema.

Important: Serevent Diskus is not a rescue inhaler. It will not relieve sudden breathing problems. For asthma treatment, it must always be used together with an inhaled corticosteroid — never alone.

See full Salmeterol Oral Inhalation drug information

Keep checking

Other Drugs & N-acetyl Cysteine (nac)

Browse every other medication we’ve checked against N-acetyl Cysteine (nac) — both the ones with a known interaction and the ones without. Select any drug for the full detail.

1Major

293Moderate

0Minor

2,535No known interaction

1 Major 293 Moderate 2,535 No interaction

Major

1 interaction

Nitroglycerin ›

Moderate

293 interactions

Showing 60 of 293 moderate interactions — see all 293 on the N-acetyl Cysteine (nac) page.

No interaction 2,535 drugs checked — show the list

We also checked N-acetyl Cysteine (nac) against these medications and found no known interaction in our sources. Open any page to confirm.

Showing the 60 most looked-up of 2,535 medications checked with no known interaction — see the full N-acetyl Cysteine (nac) list.

See the full N-acetyl Cysteine (nac) interactions page

See every supplement checked against Salmeterol, ranked by severity

Evidence & sources

N-acetyl Cysteine (nac) References

The 86 references that drive our N-acetyl Cysteine (nac) monograph and interaction data, from the evidence-graded Natural Medicines (TRC Healthcare) database. Citations with a link open the study on PubMed or the publisher’s site.

Ellenhorn MJ, et al. Ellenhorn's Medical Toxicology: Diagnoses and Treatment of Human Poisoning. 2nd ed. Baltimore, MD: Williams & Wilkins, 1997.
Jepsen S, Hansen AB. The influence of N-acetylcysteine on the measurement of prothrombin time and activated partial thromboplastin time in healthy subjects. Scand J Clin Lab Invest 1994;54:543-7. PubMed
van Zandwijk N, Dalesio O, Pastorino U, et al. EUROSCAN, a randomized trial of vitamin A and N-acetylcysteine in patients with head and neck cancer or lung cancer. For the European Organization for Research and Treatment of Cancer Head and Neck and Lung C DOI
Horowitz RS, Dart RC, Jarvie DR, et al. Placental transfer of N-acetylcysteine following human maternal acetaminophen toxicity. J Toxicol Clin Toxicol 1997;35:447-51.
Bailey B, McGuigan MA. Management of anaphylactoid reactions to intravenous N-acetylcysteine. Ann Emerg Med 1998;31:710-5. PubMed
Spiller HA, Krenzelok EP, Grande GA, et al. A prospective evaluation of the effect of activated charcoal before oral N-acetylcysteine in acetaminophen overdose. Ann Emerg Med 1994;23:519-23. PubMed
Ardissino D, Merlini PA, Savonitto S, et al. Effect of transdermal nitroglycerin or N-acetylcysteine, or both, in the long-term treatment of unstable angina pectoris. J Am Coll Cardiol 1997;29:941-7. PubMed
Horowitz JD, Henry CA, Syrjanen ML, et al. Nitroglycerine/N-acetylcysteine in the management of unstable angina pectoris. Eur Heart J 1988;9:95-100. PubMed
Louwerse ES, Weverling GJ, Bossuyt PM, et al. Randomized, double-blind, controlled trial of acetylcysteine in amyotrophic lateral sclerosis. Arch Neurol 1995;52:559-64. PubMed
Wiklund O, Fager G, Andersson A, et al. N-acetylcysteine treatment lowers plasma homocysteine but not serum lipoprotein(a) levels. Atherosclerosis 1996;119:99-106. PubMed
De Flora S, Grassi C, Carati L. Attenuation of influenza-like symptomatology and improvement of cell-mediated immunity with long-term N-acetylcysteine treatment. Eur Respir J 1997;10:1535-41. PubMed
Iversen HK. N-acetylcysteine enhances nitroglycerin-induced headache and cranial arterial responses. Clin Pharmacol Ther 1992;52:125-33. PubMed
Behr J, Maier K, Degenkolb B, et al. Antioxidative and clinical effects of high-dose N-acetylcysteine in fibrosing alveolitis. Adjunctive therapy to maintenance immunosuppression. Am J Respir Crit Care Med 1997;156:1897-901.
Tenenbein PK, Sitar DS, Tenenbein M. Interaction between N-acetylcysteine and activated charcoal: implications for the treatment of acetaminophen poisoning. Pharmacotherapy 2001;21:1331-6.
Arstall MA, Yang J, Stafford I, et al. N-acetylcysteine in combination with nitroglycerin and streptokinase for the treatment of evolving acute myocardial infarction. Safety and biochemical effects. Circulation 1995;92:2855-62.
Estensen RD, Levy M, Klopp SJ, et al. N-acetylcysteine suppression of the proliferative index in the colon of patients with previous adenomatous colonic polyps. Cancer Lett 1999;147:109-14. PubMed
Pela R, Calcagni AM, Subiaco S, et al. N-acetylcysteine reduces the exacerbation rate in patients with moderate to severe COPD. Respiration 1999;66:495-500.. PubMed
Oldemeyer JB, Biddle WP, Wurdeman RL, et al. Acetylcysteine in the prevention of contrast-induced nephropathy after coronary angiography. Am Heart J 2003;146:E23. . PubMed
Ekins BR, Ford DC, Thompson MI, et al. The effect of activated charcoal on N-acetylcysteine absorption in normal subjects. Am J Emerg Med. 1987;5(6):483-7. PubMed
Chamberlain JM, Gorman RL, Oderda GM, Klein-Schwartz W, Klein BL. Use of activated charcoal in a simulated poisoning with acetaminophen: a new loading dose for N-acetylcysteine? Ann Emerg Med. 1993;22(9):1398-402. PubMed
Renzi FP, Donovan JW, Martin TG, Morgan L, Harrison EF. Concomitant use of activated charcoal and N-acetylcysteine. Ann Emerg Med. 1985;14(6):568-72. DOI
North DS, Peterson RG, Krenzelok EP. Effect of activated charcoal administration on acetylcysteine serum levels in humans. Am J Hosp Pharm. 1981;38(7):1022-4. DOI
Loscalzo J. N-Acetylcysteine potentiates inhibition of platelet aggregation by nitroglycerin. J Clin Invest. 1985;76(2):703-8. PubMed
Ruiz FJ, Salom MG, Inglés AC, et al. N-acetyl-L-cysteine potentiates depressor response to captopril and enalaprilat in SHRs. Am J Physiol. 1994;267(3 Pt 2):R767-72. PubMed
Deharo E, Barkan D, Krugliak M, Golenser J, Ginsburg H. Potentiation of the antimalarial action of chloroquine in rodent malaria by drugs known to reduce cellular glutathione levels. Biochem Pharmacol. 2003;66(5):809-17. PubMed
Buckley, N. A., Whyte, I. M., O'Connell, D. L., and Dawson, A. H. Oral or intravenous N-acetylcysteine: which is the treatment of choice for acetaminophen (paracetamol) poisoning? J Toxicol.Clin Toxicol. 1999;37(6):759-767.
Sunman, W., Hughes, A. D., and Sever, P. S. Anaphylactoid response to intravenous acetylcysteine. Lancet 5-16-1992;339(8803):1231-1232. PubMed
Reynard, K., Riley, A., and Walker, B. E. Respiratory arrest after N-acetylcysteine for paracetamol overdose. Lancet 9-12-1992;340(8820):675. PubMed
BERNSTEIN, I. L. and AUSDENMOORE, R. W. IATROGENIC BRONCHOSPASM OCCURRING DURING CLINICAL TRIALS OF A NEW MUCOLYTIC AGENT, ACETYLCYSTEINE. Dis.Chest 1964;46:469-473. PubMed
REAS, H. W. THE USE OF N-ACETYLCYSTEINE IN THE TREATMENT OF CYSTIC FIBROSIS. J Pediatr 1964;65:542-557. PubMed
Bibi, H., Seifert, B., Oullette, M., and Belik, J. Intratracheal N-acetylcysteine use in infants with chronic lung disease. Acta Paediatr. 1992;81(4):335-339. PubMed
Jepsen, S., Herlevsen, P., Knudsen, P., Bud, M. I., and Klausen, N. O. Antioxidant treatment with N-acetylcysteine during adult respiratory distress syndrome: a prospective, randomized, placebo-controlled study. Crit Care Med 1992;20(7):918-923. PubMed
Roes, E. M., Raijmakers, M. T., Boo, T. M., Zusterzeel, P. L., Merkus, H. M., Peters, W. H., and Steegers, E. A. Oral N-acetylcysteine administration does not stabilise the process of established severe preeclampsia. Eur.J Obstet.Gynecol.Reprod.Biol 2006
Spiller, H. A., Winter, M. L., Klein-Schwartz, W., and Bangh, S. A. Efficacy of activated charcoal administered more than four hours after acetaminophen overdose. J Emerg.Med 2006;30(1):1-5. PubMed
Tirouvanziam, R., Conrad, C. K., Bottiglieri, T., Herzenberg, L. A., Moss, R. B., and Herzenberg, L. A. High-dose oral N-acetylcysteine, a glutathione prodrug, modulates inflammation in cystic fibrosis. Proc Natl.Acad.Sci U.S.A 3-21-2006;103(12):4628-463
Niemi, T. T., Munsterhjelm, E., Poyhia, R., Hynninen, M. S., and Salmenpera, M. T. The effect of N-acetylcysteine on blood coagulation and platelet function in patients undergoing open repair of abdominal aortic aneurysm. Blood Coagul.Fibrinolysis 2006;1 PubMed
Komisarof, J. A., Gilkey, G. M., Peters, D. M., Koudelka, C. W., Meyer, M. M., and Smith, S. M. N-acetylcysteine for patients with prolonged hypotension as prophylaxis for acute renal failure (NEPHRON). Crit Care Med 2007;35(2):435-441. PubMed
Grimble, G. K. Adverse gastrointestinal effects of arginine and related amino acids. J Nutr 2007;137(6 Suppl 2):1693S-1701S. PubMed
Berk, M., Copolov, D. L., Dean, O., Lu, K., Jeavons, S., Schapkaitz, I., Anderson-Hunt, M., and Bush, A. I. N-acetyl cysteine for depressive symptoms in bipolar disorder--a double-blind randomized placebo-controlled trial. Biol Psychiatry 9-15-2008;64(6) PubMed
Shahin, A. Y., Hassanin, I. M., Ismail, A. M., Kruessel, J. S., and Hirchenhain, J. Effect of oral N-acetyl cysteine on recurrent preterm labor following treatment for bacterial vaginosis. Int J Gynaecol.Obstet. 2009;104(1):44-48. PubMed
Nigwekar, S. U. and Kandula, P. N-acetylcysteine in cardiovascular-surgery-associated renal failure: a meta-analysis. Ann Thorac.Surg 2009;87(1):139-147. PubMed
Sandilands, E. A. and Bateman, D. N. Adverse reactions associated with acetylcysteine. Clin Toxicol.(Phila) 2009;47(2):81-88. PubMed
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Medication overviews come from MedlinePlus (NIH); supplement label data from the NIH Dietary Supplement Label Database. Content is written and reviewed by licensed HelloPharmacist pharmacists — see our data sources and editorial standards.

Pharmacist Counseling Corner

Taking N-acetyl Cysteine (nac) and Salmeterol Together: Common Questions

Is it safe to take N-acetyl Cysteine (nac) with Salmeterol?

We do not list a known interaction between N-acetyl Cysteine (nac) and Salmeterol. That does not guarantee the combination is risk-free, so confirm with your pharmacist or doctor — especially if you take other medications or have a health condition.

Do N-acetyl Cysteine (nac) and Salmeterol have any of the same side effects?

Yes — our sources link each of them separately to 4 of the same effects. That is not an interaction: neither changes how your body handles the other. It does mean that if one of those effects turns up, it can be harder to tell which one is behind it. They are listed on this page with the source behind each.

Should I take N-acetyl Cysteine (nac) and Salmeterol at the same time of day?

At least one FDA label for a product containing Salmeterol says to take it on an empty stomach, and supplements are usually taken with a meal — so taking them together at breakfast is the easy mistake. Where that applies, keep Salmeterol on its own and move N-acetyl Cysteine (nac) to a meal later in the day. Food instructions belong to the product rather than the ingredient, so check the directions on your own box. This is about absorption, not an interaction.

Are N-acetyl Cysteine (nac) and Salmeterol used for the same thing?

They overlap in purpose, which usually means the real question is whether you need both rather than whether they are safe together. This page lists the shared uses and how strong the evidence is for N-acetyl Cysteine (nac) in each. That is a conversation for your prescriber, especially if Salmeterol is being adjusted to a target.

How was the N-acetyl Cysteine (nac) and Salmeterol combination checked?

Interactions in our licensed database are recorded against drug classes. Salmeterol is filed under 3 classifications, and N-acetyl Cysteine (nac) has documented interactions with 5 drug classes — none of Salmeterol's classifications are among them. A medication can belong to classes beyond those recorded in our dataset, so this describes how the check was run rather than guaranteeing safety.

Does N-acetyl Cysteine (nac) interact with any other medications?

Yes. N-acetyl Cysteine (nac) has 294 documented drug interactions in our database — Salmeterol is simply not one of them. If you take anything else, it is worth checking each one; they are all listed on this page.

Does Salmeterol interact with any supplements?

Yes. Salmeterol has documented interactions with 141 supplements in our database — N-acetyl Cysteine (nac) is not one of them. The Salmeterol interaction page linked on this page lists every one, ranked by severity.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

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This information is for education only and is not a substitute for professional medical advice. Always check with your pharmacist or doctor before starting, stopping, or combining supplements and medications.