Cayston (Aztreonam)

What is a Generic Drug?

A generic drug is a copy of the brand-name drug with the same dosage, safety, strength, quality, consumption method, performance, and intended use. Before generics become available on the market, the generic company must prove it has the same active ingredients as the brand-name drug and works in the same way and in the same amount of time in the body.

The only differences between generics and their brand-name counterparts is that generics are less expensive and may look slightly different (eg. different shape or color), as trademarks laws prevent a generic from looking exactly like the brand-name drug.

Generics are less expensive because generic manufacturers don't have to invest large sums of money to develop a drug. When the brand-name patent expires, generic companies can manufacture a copy of the brand-name and sell it at a substantial discount.

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  • Product Details


    Cayston (Aztreonam) is an inhaled antibiotic designed specifically for individuals with cystic fibrosis who are battling lung infections caused by the bacterium Pseudomonas aeruginosa. When inhaled, it helps to improve breathing symptoms. It contains the active ingredient aztreonam, which is a type of medication known as a monobactam antibiotic. This antibiotic operates by disrupting the bacteria's cell wall, which is essential for their survival, ultimately leading to their death. Its formulation allows delivery directly to the lungs through a nebulizer. Aztreonam for injection is different and should not be used in nebulizers as it has not been designed for inhalation.


    When taking Cayston (aztreonam for inhalation solution), it's crucial to follow the specific instructions for proper use. Patients should administer the medication using the ALTERA Nebulizer System. They typically inhale one dose, three times a day, during a 28-day on, followed by a 28-day off cycle. The correct dosage involves mixing an entire vial of Cayston with a saline solution immediately before use, ensuring the entire mixture is transferred to the nebulizer's medication reservoir. Patients must sit in an upright position and breathe normally through the mouthpiece when inhaling the medication. It's important to adhere to the prescribed schedule without skipping doses, and to be aware that while Cayston may help improve breathing symptoms in cystic fibrosis patients with Pseudomonas aeruginosa, it's not intended to cure the condition. Keep track of doses to maintain the cycle and consult a healthcare provider if there's any doubt about the correct usage.


    Cayston is a medication that consists primarily of the active ingredient Aztreonam, which is a type of antibiotic known as a monobactam. It's different from other beta-lactam antibiotics due to its monocyclic structure. Specifically designed for inhalation, Cayston comes in a lyophilized (freeze-dried) powder form that is later reconstituted with a diluent for nebulization. The diluent typically contains sodium chloride. In the lyophilized form, along with aztreonam, Cayston may also contain the non-medicinal ingredient lysine, which aids in stabilizing the medication.


    Avoid taking or using Cayston if you have a known allergy to Aztreonam.


    • Consult a healthcare provider about the following before using Cayston:
      • Any other health conditions
      • Any allergies you have
      • A list of all medications you are currently using
      • If you are pregnant or breastfeeding
    • Stop using Cayston and seek immediate medical attention if you develop facial rashes, swelling, or experience throat tightness.
    • Be alert for sudden breathing difficulties during treatment, particularly if a bronchodilator hasn't been used.
    • If your breathing capacity declines after finishing a Cayston treatment, consult your doctor to see if it's related to a lung problem.
    • Only use Cayston if a Pseudomonas aeruginosa infection is confirmed to prevent the development of drug-resistant bacteria.

    Side Effects

    The typical side effects of Cayston include cough, nasal congestion, wheezing, sore throat, and fever, with fever more commonly observed in children. Users may also experience chest discomfort, abdominal pain, and vomiting.

    Cayston can cause severe allergic reactions, marked by symptoms such as rash, facial swelling, throat tightness, and difficulty breathing. Another serious side effect is bronchospasm, which includes symptoms like shortness of breath, wheezing, and chest tightness. These reactions are particularly risky right after administering Cayston. To reduce the risk of bronchospasm, it is advised to use an inhaled bronchodilator before each Cayston treatment. If severe allergic reactions or bronchospasm occur, discontinue use immediately and seek medical assistance.


    1. Cayston (Aztreonam) Product Monograph. Foster City, CA: Gilead Sciences, Inc.; 2019.
    2. Cayston (Aztreonam) Drug Label Information. Foster City, CA: Gilead Sciences, Inc.; 2021.

    IMPORTANT NOTE: The above information is intended to increase awareness of health information and does not suggest treatment or diagnosis. This information is not a substitute for individual medical attention and should not be construed to indicate that use of the drug is safe, appropriate, or effective for you. See your health care professional for medical advice and treatment.

    Product Code : 14913

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