pulmonary therapy Flashcards
Theophylline-MOA & Drug class (theophyline and aminophylline)
Drug class: Phosphodiesterase inhibitor bronchodilator
MOA:
Competitively inhibit phosphodiesterase III (and PDE IV to a lesser extent), thereby increasing amounts of CAMP that then increase release endogenous epinephrine. The elevated concentrations of CAMP may also INHIBIT the release of histamine and slow reacting substance of anaphylaxis..
-myocardial and neuromuscular transmission effects=may result from translocating intracellular ionized calcium & adenosine antagonism may contribute to CNS stimulation effects*
-Pulmonary: relaxes smooth muscles in bronchi and pulmonary vasculature (vasodilation in aa and vv), improve mucociliary clearance, improves diaphgram contractility, can cause centrally mediated resp stimulation + INHIBITS EOSES IN THE AIRWAY**
-smooth muscle relaxant affects also occur in biliary system, uterus, GIT (increase secretion of gastric acid and steroi activity); inhibit MCT release
-Weak chronotropic and inotropic action
-Has anti-inflammatory effects, including diminihsed activity of inflammatory and immune cells, esp EOSES IN THE AIWAYS
Which of the following drugs has the ability to enhance theophylline activity?
Fluoroquinolones
Theophylline contraindicated with?
patients that are hypersensitive to xanthines (caffine,, theobromine, aminophylline) and use with dogs with epileptic seizures is contraindicated **
Theophylline should be administered with caution in patients with severe cardiac disease, gastric ulcers, hyperthyroidism, renal or hepatic disease, severe hypoxia, or hypertension.**
-Theophylline clearance is decreased by ≈50% in patients with hepatic disease or CHF, and a 50% reduction in dosage has been suggested for patients in hepatic failure.
-Clearance is reduced to a lesser extent by hypothyroidism, fever, and sepsis. Because it may cause or worsen pre-existing arrhythmias, caution and enhanced monitoring are advised in patients with cardiac tachyarrhythmias that receive theophylline.
-Neonatal and geriatric patients may have decreased clearances of theophylline and be more sensitive to its toxic effect
