Pharmacology · chapter 25 · Lower Respiratory Disorder Drugs
Xanthines, Leukotriene Modifiers, and Mast Cell Stabilizers
The 14 things this section of the textbook says that you are most likely to be asked about — quoted word for word, not retold. Then 6 practice questions with the reasoning.
Key points
How xanthines work
Xanthines work by relaxing the smooth muscles in the airways, which helps to open the bronchial passages and improve breathing. They also have some anti-inflammatory effects and can enhance the contractility of the diaphragm.
Narrow therapeutic window
It has a narrow therapeutic window, requiring careful monitoring of blood levels to ensure efficacy and prevent toxicity. The therapeutic serum levels of theophylline are 10–20 mcg/mL.
Signs of theophylline toxicity
Clients with theophylline toxicity may present with abdominal pain, blurred vision, confusion, nausea, and vomiting.
Avoid caffeine with theophylline
Clients taking theophylline should avoid other CNS stimulants such as caffeine (Cunha, 2021).
Xanthine adverse effects
Xanthines can have a variety of potential adverse effects, including nausea, vomiting, restlessness, nervousness, increased heart rate, and tremors.
Who should not use xanthines
Clients with hypersensitivity, seizure disorder, hyperthyroidism, and severe cardiac arrhythmias should not use xanthines (Khan, 2021).
What leukotriene modifiers do
By blocking the effects of leukotrienes, leukotriene modifiers help to reduce inflammation, bronchoconstriction, and mucus production in the airways.
Montelukast is taken at night
Montelukast is taken at night due to its short half-life and to ensure peak drug levels with symptom onset (Cleveland Clinic, 2023b).
Zafirlukast, zileuton and the liver
Both zafirlukast and zileuton should be avoided in clients who are hypersensitive and in clients with hepatic impairment.
Montelukast neuropsychiatric warning
Serious neuropsychiatric events have been reported in clients taking montelukast. Agitation, hostile and/or aggressive behavior, depression, and suicidality have been seen.
How mast cell stabilizers work
These medications work by preventing the release of inflammatory substances, particularly histamine, from mast cells.
Cromolyn is preventive only
It is available as an inhaler for asthma and is most effective when used prophylactically, before exposure to triggers, because it does not provide immediate relief of symptoms (Science Direct, 2019).
Keep lab appointments
Take drug with water and/or food to minimize GI distress. Keep appointments for lab draws to monitor medication levels.
Not rescue medications
From the book’s list of what the client should not do:
Stop taking the drug abruptly. Use these medications as rescue medications in acute asthma attacks.
Terms to know
- Leukotriene modifiers
- Leukotriene modifiers, also known as leukotriene receptor antagonists or leukotriene inhibitors, are a class of medications used to manage various inflammatory conditions, particularly asthma.
- leukotrienes
- These medications target leukotrienes, which are inflammatory substances produced in the body in response to certain triggers.
- Mast cell stabilizers
- Mast cell stabilizers are medications used to manage allergic conditions such as asthma and allergic rhinitis.
- Xanthines
- Xanthines are a class of drugs that have been used for many years to manage respiratory conditions, particularly asthma and COPD.
Practice questions
Stuck on select-all-that-apply? How to take them one option at a time.
The graded version needs JavaScript. Every question is below anyway, with the answer and why.
Every question here, with the answer
A client on theophylline reports nausea, vomiting, blurred vision, and confusion. What should the nurse suspect?
- Theophylline toxicity
- Allergic rhinitis
- An expected response to a new dose
- Low blood glucose from the drug
Answer: Theophylline toxicity
Abdominal pain, blurred vision, confusion, nausea, and vomiting are signs of theophylline toxicity; the drug has a narrow therapeutic window. These are not expected effects to ignore.
A theophylline level comes back at 25 mcg/mL. How should the nurse interpret it?
- Below the therapeutic range
- Above the therapeutic range of 10–20 mcg/mL
- Within the therapeutic range
- Therapeutic levels are not measured for theophylline
Answer: Above the therapeutic range of 10–20 mcg/mL
The therapeutic serum level of theophylline is 10–20 mcg/mL, so 25 mcg/mL is above the range and raises the risk of toxicity. Blood levels are monitored because the window is narrow.
A parent reports that their teenager became unusually aggressive and withdrawn after starting montelukast. What should the nurse do?
- Reassure the parent that this is normal adolescence.
- Tell them to give the dose in the morning instead.
- Recognize a possible neuropsychiatric reaction and report it to the provider.
- Advise doubling the dose to improve asthma control.
Answer: Recognize a possible neuropsychiatric reaction and report it to the provider.
Montelukast carries a black box warning for serious neuropsychiatric events such as aggression, depression, and suicidality, and the nurse assesses and reports these. Changing the timing or dose does not address the risk.
A client is taking theophylline. Which teaching points should the nurse include? Select all that apply.
- Avoid caffeine.
- Do not stop the drug abruptly.
- Keep appointments for lab draws to check drug levels.
- Take it with water or food to reduce GI upset.
- Use it as a rescue drug during an acute asthma attack.
Answer: Avoid caffeine., Do not stop the drug abruptly., Keep appointments for lab draws to check drug levels., Take it with water or food to reduce GI upset.
Clients avoid CNS stimulants such as caffeine, keep lab appointments, do not stop abruptly, and take the drug with water or food. These drugs are not rescue medications for acute attacks.
A client with asthma uses cromolyn sodium and asks why it did not help during a sudden attack. Which response is accurate?
- Cromolyn relieves attacks within seconds if inhaled deeply.
- You need to double the dose during attacks.
- Cromolyn works best when used before exposure to triggers; it does not give immediate relief.
- Cromolyn works only when taken with caffeine.
Answer: Cromolyn works best when used before exposure to triggers; it does not give immediate relief.
Cromolyn is most effective when used prophylactically because it does not provide immediate relief. Doubling the dose or adding caffeine does not make it a rescue drug.
Which clients should NOT receive a xanthine such as theophylline? Select all that apply.
- A client with stable COPD who has not responded to other treatments
- A client with a seizure disorder
- A client with severe cardiac arrhythmias
- A client with hyperthyroidism
- A client with hypersensitivity to the drug
Answer: A client with a seizure disorder, A client with severe cardiac arrhythmias, A client with hyperthyroidism, A client with hypersensitivity to the drug
Clients with hypersensitivity, seizure disorder, hyperthyroidism, and severe cardiac arrhythmias should not use xanthines. Xanthines can still be an option for COPD clients who do not respond well to other treatments.
Where every quote comes from
Section 25.3 Xanthines, Leukotriene Modifiers, and Mast Cell Stabilizers of Pharmacology for Nurses by Tina Barbour-Taylor, Leah Mueller (Sabato), Donna Paris, Dorie Weaver, OpenStax, 2024. Read the whole section free at openstax.org.
The textbook is licensed under CC BY-NC-SA 4.0. This page quotes it word for word and adds the headings, the order and the practice questions; references to the book's figures and stray spaces left by its formatting are removed. The page is shared under the same licence. Nothing here is sold.