Theophyllines Flashcards
How do Theophylline’s work?
info for this drug from drug.com as not in book
Mechanism(s) of action not known with certainty; appears that bronchodilation is mediated by competitive inhibition of 2 isozymes of phosphodiesterase (PDE III and, to a lesser extent, PDE IV), while non-bronchodilator prophylactic actions are probably mediated through molecular mechanisms that do not involve inhibition of PDE III or antagonism of adenosine receptors.
Relaxes smooth muscles (i.e., bronchodilation) and suppresses the response of the airways to stimuli (i.e., non-bronchodilator prophylactic effects).
Relieves shortness of breath, wheezing and dyspnea, and improves pulmonary function as measured by increased flow rates and vital capacity.
Increases the force of contraction of diaphragmatic muscles.
Positive inotropic effect on the myocardium and a positive chronotropic effect at the sinoatrial (SA) node.
Directly dilates coronary, pulmonary, renal, and general systemic arterioles and veins, decreasing peripheral vascular resistance and venous pressure. Generally only a slight increase in BP following administration of moderate doses of theophylline.
Stimulates all levels of CNS but to a lesser degree than caffeine. Constricts cerebral vasculature; resultant decrease in cerebral blood flow and increase in carbon dioxide tension may result in respiratory center stimulation in some patients.
Has a mild diuretic effect.
May increase basal metabolic rate.
Stimulates gastric secretion, relaxes smooth muscle of biliary and GI tract.
Tolerance of low magnitude may develop to diuretic and sleep-disturbing effects of xanthine derivatives; tolerance to bronchodilator effects rarely occurs.
Indications for Theophylline’s
Symptomatic management or prevention of asthma and reversible bronchospasm associated with COPD, including chronic bronchitis and emphysema
Contraindications of Theophylline’s
Known allergy or hypersensitivity to any of the theophyllines, dyphylline, caffeine, aminophylline, or theobromine.
Hypersensitivity to ethylenediamine found in aminophylline.
Known allergy to corn or corn products, which may be included in dextrose-containing theophylline injections.228 k
Dyphylline: Concomitant use with other sympathomimetic agents (e.g., ephedrine) in pediatric patients.
Side effects of Theophylline’s
Nausea, vomiting, headache, insomnia, epigastric pain, abdominal cramps, anorexia, palpitations, a sinus tachycardia, extrasystoles, diarrhea, irritability,restlessness, fine skeletal muscle tremors, transient diuresis.
IV infusion (related to solution or administration technique): Febrile response, infection at injection site, venous thrombosis or phlebitis extending from injection site, extravasation, hypervolemia.
Oral (dyphylline): Nausea, headache, cardiac palpitations, CNS stimulation.
Rapid IV injection (aminophylline): Dizziness, faintness, lightheadedness, palpitation, syncope, precordial pain, flushing, profound bradycardia, premature ventricular contractions, severe hypotension, cardiac arrest.
IM injection (aminophylline; IM injection not recommended): Intense local pain, sloughing of tissue.
Interactions of Theophylline’s
too many!
Elimination of Theophylline’s
Renal
Patient information on Theophylline’s
Inform patients that alcohol may interact with theophylline.
Importance of contacting their clinician if they develop a new illness or worsening of a chronic illness, especially if accompanied by a persistent fever.
Instruct patients that if a dose is missed to take the next dose at the usually scheduled time and not to attempt to make up for the missed dose.
Importance of informing their clinician of smoking history, and to inform their clinicians if they start or stop smoking (e.g., cigarettes, marijuana).
Inform patients that major changes in diet are not recommended while taking theophylline.
Advise patients to inform all clinicians involved in their care that they are taking theophylline, especially when a medication is being added or deleted from their treatment.
Importance of informing patients that theophylline preparations should be administered in a consistent manner, either always with or always without food.
Importance of not altering administration schedule of theophylline preparations without consulting clinician.
Importance of informing patients to seek medical advice whenever nausea, vomiting, persistent headache, fever, insomnia, or rapid heartbeat occurs during treatment with theophylline, even if another cause is suspected.
Inform patients to discontinue the drug if they experience toxicity.
Importance of informing clinicians of existing or contemplated concomitant therapy, including prescription and OTC drugs, as well as any concomitant illnesses.
Importance of women informing clinicians if they are or plan to become pregnant or plan to breast-feed.
