Exam 20 - Drugs for Resp. System

Antihistamines

• Antihistamines work by blocking histamine from attaching to H1 receptors.
• Actions reduce inflammatory and allergic symptoms.
• Antihistamines do not prevent histamine release, but rather block the receptors, limiting vasodilation, capillary leak, swelling, and bronchoconstriction.
• Uses include treating various allergic reactions like allergic rhinitis.

First-generation Antihistamines

• First-generation antihistamines are available over-the-counter (OTC).
• They cross the blood-brain barrier, causing sedation, and have anticholinergic effects.
• They are effective for short-term relief of sneezing, itching, and runny nose.

Second-generation Antihistamines

• Second-generation antihistamines are newer and have a faster onset with less sedation.
• They do not cross the blood-brain barrier, and some are prescription while some are OTC.
• They are generally less effective against nasal congestion than first-generation antihistamines.

Antihistamine Side Effects

• Side effects include drowsiness, dry mouth, increased heart rate, increased blood pressure, dilated pupils, and urinary retention.

Antihistamine Adverse Effects

• Adverse effects include severe anticholinergic effects (cardiac dysrhythmias, high BP), and increased intraocular pressure in glaucoma.
• Overdose symptoms include nervousness, anxiety, agitation, progressing to confusion, delirium, and hallucinations.
• Paradoxical reactions like hyperexcitability, agitation, or confusion can occur in children and older adults.

Antihistamine Life Span Considerations

• Older adults may experience pronounced anticholinergic effects, such as constipation, dry mouth, and urinary retention.
• Older adults are also at risk for dizziness, syncope, and confusion.

Antihistamine Examples

• Examples of antihistamines include diphenhydramine (Benadryl), fexofenadine (Allegra), loratadine (Claritin).

Antihistamine Drug Interactions

• Drug interactions include increased sedation with other CNS depressants, enhanced anticholinergic effects with other anticholinergic drugs, and may mask ototoxicity symptoms.

Antihistamine Nursing Implications/Patient Teaching

• Caution patients about drowsiness and activities requiring alertness.
• Advise increased fluid intake, unless it is contraindicated.
• Patients should be told not to increase the dose or drink alcohol.
• Instruct patients to report skin reactions and inform them about tolerance to the medication.
• Patients should not take other medications, especially sedatives, without talking to a healthcare provider.
• Monitor for side effects like dizziness, syncope, and confusion in older adults.
• Patients with thyroid disease or migraines may not be able to take antihistamines because of tachycardia.

Leukotriene Inhibitors

• Leukotriene Inhibitors block the leukotriene response, reducing allergy and asthma symptoms.
• Some block production, while others block receptors; both actions reduce inflammation.
• Uses includes for allergic rhinitis, relaxes respiratory smooth muscle, increases airflow, and prevents and treats asthma.
• Side effects include headache, nausea, and diarrhea.
• Adverse effects are rare, but liver dysfunction is possible with long-term use.
• Examples include montelukast (Singulair) and zafirlukast (Accolate).
• Drug interactions include interaction with drugs that stimulate liver metabolism (phenytoin, phenobarbital, carbamazepine, and rifampin).
• Montelukast has the least interactions.

Leukotriene Inhibitors Nursing Implications/Patient Teaching

• These are not for acute asthma attacks because of their slow onset.
• Teach patients to report increased asthma or allergy symptoms and caution use in pregnancy/breastfeeding.
• Advise patients not to stop taking these drugs suddenly.
• Teach patients to report signs of liver impairment such as yellowing of the skin or eyes, darkening of urine, or white/gray stools.
• Monitor and report changes in behavior or mood.

Mast Cell Stabilizers

• Mast cell stabilizers prevent mast cells from releasing inflammatory mediators.
• Uses include for nasal allergies and asthma as inhaled drugs.
• Side effects include headache, unpleasant taste, nosebleed, and temporary nasal stinging.
• Examples include cromolyn sodium (NasalCrom) and nedocromil sodium
• Mild stinging or burning can be expected.
• Advise patients to rinse the mouth and gargle after use to minimize dry mouth, throat irritation, and hoarseness.
• These drugs must be used daily as prescribed, not rapid acting.

Decongestants

• Decongestants reduce the swelling of nasal passages by shrinking blood vessels.
• Sympathomimetics mimic the body's adrenaline.
• Uses relieve nasal congestion due to stuffiness and pressure and also decrease congestion around the eustachian tubes.
• Side effects include local irritation and dryness of mucous membranes.
• Systemic effects can occur with overuse, leading to nervousness, insomnia, tremors, and heart palpitations.
• Oral decongestants may cause headache, nervousness, dizziness, insomnia, and tremors.
• Adverse effects can cause cardiac dysrhythmias, hypertension, and palpitations, potentially leading to a heart attack.
• Rebound congestion can occur with overuse of nasal sprays.
• Examples include oxymetazoline (Afrin) and pseudoephedrine (Sudafed).
• Drug interactions can occur with caffeine, MAOIs, amphetamines, ergotamine, selegiline, and linezolid.
• Relief is immediate with sprays/drops.
• Use nasal sprays for only a few days to prevent tolerance and rebound congestion.
• Caution patients not to swallow the spray.
• Advise caution for patients with hypertension, heart disease, glaucoma, or prostate enlargement.
• Take oral forms at least 4 hours before bed to prevent insomnia.
• Monitor heart rate and blood pressure.

Mucolytics

• Mucolytics decrease the thickness of respiratory secretions, aiding in their removal.
• They increase fluid in the respiratory tract, which helps break down mucus.
• Uses treat a productive cough that is useful in COPD and with coughs associated with viral upper respiratory infections.
• Side effects include GI upset, dizziness, headache, and rash.
• Side effects are not for children younger than 2 years or 6 years for some products, due to overdosage risk.
• An example is guaifenesin (Mucinex).
• Patients should be monitored for thinner secretions.
• Ask about dosage if side effects occur.
• Ask about back pain and difficulty urinating, as high dosages can cause kidney stones.
• Tell patients to seek care if symptoms do not improve within a few days.
• Instruct patients that the mucolytic makes sputum easier to expectorate, but will not stop coughing alone.
• Advise using a humidifier and drinking at least 2 quarts of water daily.
• Instruct patients to take the drug with a full glass of water.
• Advise patients to avoid driving or activities requiring alertness until they know how they respond to the drug due to dizziness.

Antitussives

• Antitussives relieve or suppress coughing by acting centrally on the cough center in the brain, peripherally by anesthetizing stretch receptors in the respiratory tract, or locally by soothing irritated areas in the throat.
• Uses reduce coughing.
• Side effects include drowsiness, dry mouth, nausea, postural hypotension, and constipation with codeine.
• Adverse effects are that opioid antitussives have additive effects with other CNS depressants.
• Should not be for children younger than 2 years or 6 years for some products, due to overdosage risk.
• Examples include benzonatate (Tessalon Perles) and dextromethorphan (Delsym).
• Opioid antitussives should be used with caution in patients with COPD.
• Instruct patients to take the drug as prescribed and advise of caution when doing tasks that require alertness while taking an opioid antitussive.
• Advise patients about constipation with codeine containing antitussives.
• Tell patients not to take opioid antitussives with alcohol or other CNS depressants.
• Advise patients to change positions slowly when getting up.

Bronchodilators

• Bronchodilators relax airway smooth muscles, widening the airways by stimulating beta2-adrenergic receptors.
• SABAs rapidly bind to beat2 receptors for quick relief.
• LABAs bind to beat2 receptors over time for continuous relaxation.
• Cholinergic antagonists prevent the nervous system from releasing acetylcholine, allowing the body's own adrenaline to activate beta2 receptors.
• Uses are for asthma and COPD, preventing or treating bronchospasms, and other respiratory infections.
• SABAs are reliever/rescue drugs for acute attacks and LABAs/cholinergic antagonists are controller/prevention drugs.
• Side effects include hypertension, tachycardia, headache, insomnia, nervousness, tremors, dry mouth, and bad taste.
• Adverse effects include how heavy use can cause constriction of heart vessels, leading to chest pain or myocardial infarction.
• Examples include albuterol (ProAir HFA), salmeterol (Serevent), ipratropium (Atrovent), and theophylline.
• Drug interactions include MAOIs, tricyclic antidepressants, beta-blockers, other antihypertensives, digoxin, potassium-losing diuretics, and caffeine-containing herbs.
• Baseline vital signs should be taken, and cardiovascular disease should be assessed.
• Teach patients to take the drug as directed and not change the dose.
• Overuse can result in severe side effects.
• Contact a health provider if the drug is not helping with breathing.
• Report any bronchial irritation, dizziness, chest pain, insomnia, or changes in symptoms.
• Drink lots of fluids, especially water.
• Do not take any OTC drugs without checking with a healthcare provider.
• Use the reliever inhaler 15-30 minutes prior to exercise to prevent exercise-induced bronchospasm.
• Shake the inhaler well before using.
• Follow the instructions for correct use of the inhaler, rinse mouth with water after using inhaler, keep count of sprays used, and replace inhaler as needed.
• Clean the mouthpiece at least once per week.
• Use a SABA inhaler before a corticosteroid inhaler when using them both.
• Teach patients with asthma to always have their SABA reliever drug with them.

Corticosteroids

• Corticosteroids prevent or limit inflammation and allergy by slowing or stopping the production of histamine and leukotriene.
• They decrease inflamed airways by preventing mast cells and WBCs in the respiratory mucosa from releasing inflammatory mediators, but do not cause bronchodilation.
• Uses are for allergic reactions, allergies, and asthma, and nasal corticosteroids decrease inflammation and swelling in nasal membranes.
• Side effects include sodium retention, hyperglycemia, increased blood pressure, weight gain, bruising, and reduced immunity.
• Drug interactions increase the effects of barbiturates, sedatives, narcotics, and anticoagulants, and decrease the effects of insulin, oral hypoglycemics, isoniazid, and broad-spectrum antibiotics.
• Examples include beclomethasone (Qvar), fluticasone (Flovent), and fluticasone (Flonase).
• Do not use in patients with sputum containing Candida or who have systemic fungal infections.
• Advise patients to rinse their mouths after each use to prevent fungal infection.
• Inhaled corticosteroids are not used to treat an acute asthma attack because they are not bronchodilators.
• Teach patients to use these drugs daily as prescribed, even when no symptoms are present.
• Advise patients to notify the healthcare professional if white patches appear in the mouth or throat.
• Teach patients how to properly use the MDI and DPI devices.

Antitubercular Drugs

• Antitubercular drugs are bactericidal and bacteriostatic and control TB organisms.
• Uses include the direct treatment of TB infection and for prophylaxis in people heavily exposed to the organism.
• First-line drugs include Isoniazid (INH), rifampin (Rifadin), pyrazinamide, and ethambutol (Myambutol).
• Isoniazid (INH) kills active mycobacteria and inhibits the growth of dormant bacteria

Isoniazid (INH) Nursing Implications

• Avoid antacids and take on an empty stomach.
• Supplement with B-complex vitamins or vitamin B6, avoid alcohol, and report signs of liver toxicity.
• Be aware of drug interactions.

Rifampin

• Rifampin kills slower-growing organisms.

Rifampin Nursing Implications

• Avoid antacids and take on an empty stomach.
• Expect reddish-orange staining and avoid soft contact lenses and alcohol and acetaminophen.
• Report signs of liver toxicity and check blood glucose in diabetic patients.
• Be aware of drug interactions.

Pyrazinamide

• Pyrazinamide kills organisms in acidic environments.

Pyrazinamide Nursing Implications

• Ask about gout history, drink at least 8 oz of water with the tablet, increase fluid intake, avoid sunlight, and alcohol, and report signs of liver toxicity.

Ethambutol

• Ethambutol inhibits bacterial RNA synthesis.

Ethambutol Nursing Implications

• Take with food to avoid stomach irritation, report changes in vision, avoid alcohol, ask about a history of gout, and increase fluid intake.
• Second-line drugs include aminoglycosides such as kanamycin (Kantrex) and capreomycin (Capastat).
• Monitor for nephrotoxicity, ototoxicity, and respiratory depression.
• Monitor liver function, vitamin B6 and B12 levels, and drug levels.
• Do not drink alcohol during treatment, and set a regular time to take anti-TB drugs.
• Take drugs exactly as directed and know what to do if a dose is missed.
• Report new symptoms promptly (bruising, fever, sore throat, unusual bleeding, rashes, mental confusion, headache, tremors, severe nausea, vomiting, diarrhea, malaise, yellowish discoloration, visual changes, excessive drowsiness, changes in personality or affect, and severe pain).
• Expect a normal reddish orange color of urine while taking rifampin, do not wear soft contact lenses, and do not take other drugs without permission.
• Take rifampin and isoniazid 1 hour before or 2 hours after meals or antacids.
• Take ethambutol with food, and keep all appointments and laboratory tests.