Medical Editor: John P. Cunha, DO, FACOEP Last updated on RxList: 11/9/2021
Cayston Side Effects Center

What Is Cayston?

Cayston (aztreonam) for Inhalation Solution is an antibiotic used to improve breathing symptoms in people who have cystic fibrosis and a certain bacteria in their lungs.

What Are Side Effects of Cayston?

Common side effects of Cayston include:

Dosage for Cayston

The recommended dose of Cayston for both adults and pediatric patients 7 years of age and older is one single-use vial (75 mg) reconstituted with 1 mL of sterile diluent administered 3 times a day 28-days (followed by 28 days off Cayston therapy). Doses should be taken at least 4 hours apart.

What Drugs, Substances, or Supplements Interact with Cayston?

Cayston may interact with other inhaled medications. Tell your doctor all medications and supplements you use.

Cayston During Pregnancy or Breastfeeding

Cayston is not expected to harm a fetus. Tell your doctor if you are pregnant or plan to become pregnant during treatment. This drug can pass into breast milk and may harm a nursing baby. Consult your doctor before breastfeeding.

Additional Information

Our Cayston (aztreonam) For Inhalation Solution Side Effects Drug Center provides a comprehensive view of available drug information on the potential side effects when taking this medication.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Cayston Consumer Information

Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.

Call your doctor at once if you have a serious side effect such as:

  • bronchospasm (wheezing, chest tightness, trouble breathing) right after using the medicine; or
  • any new or worsening symptoms.

Less serious side effects may include:

  • mild stomach discomfort, vomiting;
  • cough, sore throat;
  • stuffy nose; or
  • low fever.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Read the entire detailed patient monograph for Cayston (Aztreonam for Inhalation Solution)

Cayston Professional Information


Clinical Trials Experience

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

The safety of CAYSTON was evaluated in 344 patients from two placebo-controlled trials and one open-label follow-on trial. In controlled trials, 146 patients with CF received 75 mg CAYSTON 3 times a day for 28 days.

Table 1 displays adverse reactions reported in more than 5% of patients treated with CAYSTON 3 times a day in placebo-controlled trials. The listed adverse reactions occurred more frequently in CAYSTON-treated patients than in placebo-treated patients.

Table 1 : Adverse Reactions Reported in more than 5% of Patients Treated with CAYSTON in the Placebo-Controlled Trials

Event (Preferred Term) Placebo
(N=160) n (% )
CAYSTON 75 mg 3 times a day
(N=146) n (% )
Cough 82 (51%) 79 (54%)
Nasal congestion 19 (12%) 23 (16%)
Wheezing 16 (10%) 23 (16%)
Pharyngolaryngealpain 17 (11%) 18 (12%)
Pyrexia 9 (6%) 19 (13%)
Chest discomfort 10 (6%) 11 (8%)
Abdominal Pain 8 (5%) 10 (7%)
Vomiting 7 (4%) 9 (6%)

Adverse reactions that occurred in less than 5% of patients treated with CAYSTON were bronchospasm (3%) [see WARNINGS AND PRECAUTIONS and rash (2%).

Postmarketing Experience

In addition to adverse reactions reported from clinical trials, the following possible adverse reactions have been identified during post-approval use of CAYSTON. Because these events have been reported voluntarily from a population of unknown size, estimates of frequency cannot be made.

Musculoskeletal And Connective Tissue Disorders

Arthralgia, joint swelling

Read the entire FDA prescribing information for Cayston (Aztreonam for Inhalation Solution)

© Cayston Patient Information is supplied by Cerner Multum, Inc. and Cayston Consumer information is supplied by First Databank, Inc., used under license and subject to their respective copyrights.

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