Drug Interactions between aminophylline and Guiadrine PSE 120

MONITOR: Coadministration of two or more sympathomimetic agents may increase the risk of adverse effects such as nervousness, irritability, and increased heart rate. Central nervous system (CNS) stimulants, particularly amphetamines, can potentiate the adrenergic response to vasopressors and other sympathomimetic agents. Additive increases in blood pressure and heart rate may occur due to enhanced peripheral sympathetic activity.

MANAGEMENT: Caution is advised if two or more sympathomimetic agents are coadministered. Pulse and blood pressure should be closely monitored.

MONITOR: Coadministration of two or more sympathomimetic agents may increase the risk of adverse effects such as nervousness, irritability, and increased heart rate. Central nervous system (CNS) stimulants, particularly amphetamines, can potentiate the adrenergic response to vasopressors and other sympathomimetic agents. Additive increases in blood pressure and heart rate may occur due to enhanced peripheral sympathetic activity.

MANAGEMENT: Caution is advised if two or more sympathomimetic agents are coadministered. Pulse and blood pressure should be closely monitored.

Sympathomimetic agents may cause adverse cardiovascular effects, particularly when used in high dosages and/or in susceptible patients. In cardiac tissues, these agents may produce positive chronotropic and inotropic effects via stimulation of beta- 1 adrenergic receptors. Cardiac output, oxygen consumption, and the work of the heart may be increased. In the peripheral vasculature, vasoconstriction may occur via stimulation of alpha-1 adrenergic receptors. Palpitations, tachycardia, arrhythmia, hypertension, reflex bradycardia, coronary occlusion, cerebral vasculitis, myocardial infarction, cardiac arrest, and death have been reported. Some of these agents, particularly ephedra alkaloids (ephedrine, ma huang, phenylpropanolamine), may also predispose patients to hemorrhagic and ischemic stroke. Therapy with sympathomimetic agents should generally be avoided or administered cautiously in patients with sensitivity to sympathomimetic amines, hyperthyroidism, or underlying cardiovascular or cerebrovascular disorders. These agents should not be used in patients with severe coronary artery disease or severe/uncontrolled hypertension.

The use of theophyllines is considered by some manufacturers to be contraindicated in patients with underlying seizure disorders unless they are receiving adequate anticonvulsant therapy. Theophyllines may cause seizures, which have generally been associated with toxic drug levels but have also been reported at therapeutic concentrations in patients with head trauma or cerebral infarct. If theophylline therapy is administered in patients with these or other risk factors for seizures, serum drug levels should be monitored closely and maintained in the low therapeutic range. Intractable seizures and death have been reported during acute theophylline toxicity.

Sympathomimetic agents may cause adverse cardiovascular effects, particularly when used in high dosages and/or in susceptible patients. In cardiac tissues, these agents may produce positive chronotropic and inotropic effects via stimulation of beta- 1 adrenergic receptors. Cardiac output, oxygen consumption, and the work of the heart may be increased. In the peripheral vasculature, vasoconstriction may occur via stimulation of alpha-1 adrenergic receptors. Palpitations, tachycardia, arrhythmia, hypertension, reflex bradycardia, coronary occlusion, cerebral vasculitis, myocardial infarction, cardiac arrest, and death have been reported. Some of these agents, particularly ephedra alkaloids (ephedrine, ma huang, phenylpropanolamine), may also predispose patients to hemorrhagic and ischemic stroke. Therapy with sympathomimetic agents should generally be avoided or administered cautiously in patients with sensitivity to sympathomimetic amines, hyperthyroidism, or underlying cardiovascular or cerebrovascular disorders. These agents should not be used in patients with severe coronary artery disease or severe/uncontrolled hypertension.

The use of theophyllines is considered by some manufacturers to be contraindicated in patients with underlying seizure disorders unless they are receiving adequate anticonvulsant therapy. Theophyllines may cause seizures, which have generally been associated with toxic drug levels but have also been reported at therapeutic concentrations in patients with head trauma or cerebral infarct. If theophylline therapy is administered in patients with these or other risk factors for seizures, serum drug levels should be monitored closely and maintained in the low therapeutic range. Intractable seizures and death have been reported during acute theophylline toxicity.

Sympathomimetic agents may cause adverse cardiovascular effects, particularly when used in high dosages and/or in susceptible patients. In cardiac tissues, these agents may produce positive chronotropic and inotropic effects via stimulation of beta- 1 adrenergic receptors. Cardiac output, oxygen consumption, and the work of the heart may be increased. In the peripheral vasculature, vasoconstriction may occur via stimulation of alpha-1 adrenergic receptors. Palpitations, tachycardia, arrhythmia, hypertension, reflex bradycardia, coronary occlusion, cerebral vasculitis, myocardial infarction, cardiac arrest, and death have been reported. Some of these agents, particularly ephedra alkaloids (ephedrine, ma huang, phenylpropanolamine), may also predispose patients to hemorrhagic and ischemic stroke. Therapy with sympathomimetic agents should generally be avoided or administered cautiously in patients with sensitivity to sympathomimetic amines, hyperthyroidism, or underlying cardiovascular or cerebrovascular disorders. These agents should not be used in patients with severe coronary artery disease or severe/uncontrolled hypertension.

Methylxanthines are known to stimulate peptic acid secretion. Therapy with products containing methylxanthines should be administered with extreme caution in patients with active peptic ulcer disease. Some manufacturers consider their use to be contraindicated under such circumstance.

Sympathomimetic agents may cause adverse cardiovascular effects, particularly when used in high dosages and/or in susceptible patients. In cardiac tissues, these agents may produce positive chronotropic and inotropic effects via stimulation of beta- 1 adrenergic receptors. Cardiac output, oxygen consumption, and the work of the heart may be increased. In the peripheral vasculature, vasoconstriction may occur via stimulation of alpha-1 adrenergic receptors. Palpitations, tachycardia, arrhythmia, hypertension, reflex bradycardia, coronary occlusion, cerebral vasculitis, myocardial infarction, cardiac arrest, and death have been reported. Some of these agents, particularly ephedra alkaloids (ephedrine, ma huang, phenylpropanolamine), may also predispose patients to hemorrhagic and ischemic stroke. Therapy with sympathomimetic agents should generally be avoided or administered cautiously in patients with sensitivity to sympathomimetic amines, hyperthyroidism, or underlying cardiovascular or cerebrovascular disorders. These agents should not be used in patients with severe coronary artery disease or severe/uncontrolled hypertension.

The metabolites of theophylline, which are generally undetectable in patients with normal renal function, may accumulate in patients with renal impairment and contribute to the toxicity of theophylline. In addition, the plasma protein binding of theophylline may be significantly decreased in renal impairment, resulting in elevated free drug concentrations and further increasing the risk of toxicity. Therapy with theophyllines should be administered cautiously in patients with impaired renal function. Dosage adjustments and more intensive monitoring of serum theophylline concentrations may be required.

The use of theophyllines is considered by some manufacturers to be contraindicated in patients with underlying seizure disorders unless they are receiving adequate anticonvulsant therapy. Theophyllines may cause seizures, which have generally been associated with toxic drug levels but have also been reported at therapeutic concentrations in patients with head trauma or cerebral infarct. If theophylline therapy is administered in patients with these or other risk factors for seizures, serum drug levels should be monitored closely and maintained in the low therapeutic range. Intractable seizures and death have been reported during acute theophylline toxicity.

The use of theophyllines is associated with an increase in heart rate which may progress to supraventricular tachycardia or ventricular arrhythmia at high serum drug concentrations. Appearance of cardiac adverse effects is generally an indication of theophylline toxicity, although patients with a history of tachyarrhythmias may be more susceptible to the chronotropic effect of these drugs. Therapy with theophyllines should be administered cautiously in such patients. Caution is also advised in patients with hypertension, hyperthyroidism, angina pectoris, or recent myocardial infarction, since high dosages of the drugs are associated with positive inotropic as well as chronotropic effects. Clinical monitoring of serum drug concentrations is recommended to prevent toxicity.

Sympathomimetic agents may cause or worsen urinary difficulty in patients with prostate enlargement due to smooth muscle contraction in the bladder neck via stimulation of alpha-1 adrenergic receptors. Therapy with sympathomimetic agents should be administered cautiously in patients with hypertrophy or neoplasm of the prostate.

Certain conditions have been identified as causes of reduced theophylline clearance. They include age (neonates and infants < 1 year as well as elderly patients > 60 years) and the following concurrent diseases: acute pulmonary edema; decompensated heart failure; cor pulmonale; fever (>= 102 degrees for 24 hours or more, or lesser temperature elevations for longer periods); influenza; untreated or uncontrolled hypothyroidism; liver disease, cirrhosis or acute hepatitis; reduced renal function in infants < 3 months of age; sepsis with multi-organ failure; and shock. Therapy with theophyllines should be administered cautiously in patients presenting with one or more of these risk factors, and the dosage should be appropriately reduced to prevent toxicity. More intensive monitoring of serum theophylline concentrations may be required. Toxicity is most likely to occur when levels exceed 20 mcg/mL. Severe cases, sometimes without previous warning, have led to cardiac arrhythmias, intractable seizures, and death.

Certain conditions have been identified as causes of reduced theophylline clearance. They include age (neonates and infants < 1 year as well as elderly patients > 60 years) and the following concurrent diseases: acute pulmonary edema; decompensated heart failure; cor pulmonale; fever (>= 102 degrees for 24 hours or more, or lesser temperature elevations for longer periods); influenza; untreated or uncontrolled hypothyroidism; liver disease, cirrhosis or acute hepatitis; reduced renal function in infants < 3 months of age; sepsis with multi-organ failure; and shock. Therapy with theophyllines should be administered cautiously in patients presenting with one or more of these risk factors, and the dosage should be appropriately reduced to prevent toxicity. More intensive monitoring of serum theophylline concentrations may be required. Toxicity is most likely to occur when levels exceed 20 mcg/mL. Severe cases, sometimes without previous warning, have led to cardiac arrhythmias, intractable seizures, and death.

Sympathomimetic agents may cause increases in blood glucose concentrations. These effects are usually transient and slight but may be significant with dosages higher than those normally recommended. Therapy with sympathomimetic agents should be administered cautiously in patients with diabetes mellitus. Closer monitoring of blood glucose concentrations may be appropriate.

Certain conditions have been identified as causes of reduced theophylline clearance. They include age (neonates and infants < 1 year as well as elderly patients > 60 years) and the following concurrent diseases: acute pulmonary edema; decompensated heart failure; cor pulmonale; fever (>= 102 degrees for 24 hours or more, or lesser temperature elevations for longer periods); influenza; untreated or uncontrolled hypothyroidism; liver disease, cirrhosis or acute hepatitis; reduced renal function in infants < 3 months of age; sepsis with multi-organ failure; and shock. Therapy with theophyllines should be administered cautiously in patients presenting with one or more of these risk factors, and the dosage should be appropriately reduced to prevent toxicity. More intensive monitoring of serum theophylline concentrations may be required. Toxicity is most likely to occur when levels exceed 20 mcg/mL. Severe cases, sometimes without previous warning, have led to cardiac arrhythmias, intractable seizures, and death.

Methylxanthines increase gastric acidity and may also relax lower esophageal sphincter, which can lead to gastric reflux into the esophagus. Therapy with products containing methylxanthines should be administered cautiously in patients with significant gastroesophageal reflux.

The extended-release formulation of pseudoephedrine (Sudafed 24 Hour) contains a non-deformable material. There have been rare reports of obstructive symptoms in patients with known strictures following the ingestion of similar sustained-release products. Therapy with the extended-release formulation of pseudoephedrine should be administered cautiously in patients with preexisting severe gastrointestinal narrowing or obstruction, whether pathologic or iatrogenic.

Sympathomimetic agents can induce transient mydriasis via stimulation of alpha-1 adrenergic receptors. In patients with anatomically narrow angles or narrow-angle glaucoma, pupillary dilation can provoke an acute attack. In patients with other forms of glaucoma, mydriasis may occasionally increase intraocular pressure. Therapy with sympathomimetic agents should be administered cautiously in patients with or predisposed to glaucoma, particularly narrow-angle glaucoma.

Theophylline is removed by hemodialysis. Doses should either be scheduled for administration after dialysis or supplemental doses be given after dialysis.

The use of theophyllines is associated with an increase in heart rate which may progress to supraventricular tachycardia or ventricular arrhythmia at high serum drug concentrations. Appearance of cardiac adverse effects is generally an indication of theophylline toxicity, although patients with a history of tachyarrhythmias may be more susceptible to the chronotropic effect of these drugs. Therapy with theophyllines should be administered cautiously in such patients. Caution is also advised in patients with hypertension, hyperthyroidism, angina pectoris, or recent myocardial infarction, since high dosages of the drugs are associated with positive inotropic as well as chronotropic effects. Clinical monitoring of serum drug concentrations is recommended to prevent toxicity.

The use of theophyllines is associated with an increase in heart rate which may progress to supraventricular tachycardia or ventricular arrhythmia at high serum drug concentrations. Appearance of cardiac adverse effects is generally an indication of theophylline toxicity, although patients with a history of tachyarrhythmias may be more susceptible to the chronotropic effect of these drugs. Therapy with theophyllines should be administered cautiously in such patients. Caution is also advised in patients with hypertension, hyperthyroidism, angina pectoris, or recent myocardial infarction, since high dosages of the drugs are associated with positive inotropic as well as chronotropic effects. Clinical monitoring of serum drug concentrations is recommended to prevent toxicity.

Certain conditions have been identified as causes of reduced theophylline clearance. They include age (neonates and infants < 1 year as well as elderly patients > 60 years) and the following concurrent diseases: acute pulmonary edema; decompensated heart failure; cor pulmonale; fever (>= 102 degrees for 24 hours or more, or lesser temperature elevations for longer periods); influenza; untreated or uncontrolled hypothyroidism; liver disease, cirrhosis or acute hepatitis; reduced renal function in infants < 3 months of age; sepsis with multi-organ failure; and shock. Therapy with theophyllines should be administered cautiously in patients presenting with one or more of these risk factors, and the dosage should be appropriately reduced to prevent toxicity. More intensive monitoring of serum theophylline concentrations may be required. Toxicity is most likely to occur when levels exceed 20 mcg/mL. Severe cases, sometimes without previous warning, have led to cardiac arrhythmias, intractable seizures, and death.

Certain conditions have been identified as causes of reduced theophylline clearance. They include age (neonates and infants < 1 year as well as elderly patients > 60 years) and the following concurrent diseases: acute pulmonary edema; decompensated heart failure; cor pulmonale; fever (>= 102 degrees for 24 hours or more, or lesser temperature elevations for longer periods); influenza; untreated or uncontrolled hypothyroidism; liver disease, cirrhosis or acute hepatitis; reduced renal function in infants < 3 months of age; sepsis with multi-organ failure; and shock. Therapy with theophyllines should be administered cautiously in patients presenting with one or more of these risk factors, and the dosage should be appropriately reduced to prevent toxicity. More intensive monitoring of serum theophylline concentrations may be required. Toxicity is most likely to occur when levels exceed 20 mcg/mL. Severe cases, sometimes without previous warning, have led to cardiac arrhythmias, intractable seizures, and death.

Certain conditions have been identified as causes of reduced theophylline clearance. They include age (neonates and infants < 1 year as well as elderly patients > 60 years) and the following concurrent diseases: acute pulmonary edema; decompensated heart failure; cor pulmonale; fever (>= 102 degrees for 24 hours or more, or lesser temperature elevations for longer periods); influenza; untreated or uncontrolled hypothyroidism; liver disease, cirrhosis or acute hepatitis; reduced renal function in infants < 3 months of age; sepsis with multi-organ failure; and shock. Therapy with theophyllines should be administered cautiously in patients presenting with one or more of these risk factors, and the dosage should be appropriately reduced to prevent toxicity. More intensive monitoring of serum theophylline concentrations may be required. Toxicity is most likely to occur when levels exceed 20 mcg/mL. Severe cases, sometimes without previous warning, have led to cardiac arrhythmias, intractable seizures, and death.

The use of theophyllines is associated with an increase in heart rate which may progress to supraventricular tachycardia or ventricular arrhythmia at high serum drug concentrations. Appearance of cardiac adverse effects is generally an indication of theophylline toxicity, although patients with a history of tachyarrhythmias may be more susceptible to the chronotropic effect of these drugs. Therapy with theophyllines should be administered cautiously in such patients. Caution is also advised in patients with hypertension, hyperthyroidism, angina pectoris, or recent myocardial infarction, since high dosages of the drugs are associated with positive inotropic as well as chronotropic effects. Clinical monitoring of serum drug concentrations is recommended to prevent toxicity.

Certain conditions have been identified as causes of reduced theophylline clearance. They include age (neonates and infants < 1 year as well as elderly patients > 60 years) and the following concurrent diseases: acute pulmonary edema; decompensated heart failure; cor pulmonale; fever (>= 102 degrees for 24 hours or more, or lesser temperature elevations for longer periods); influenza; untreated or uncontrolled hypothyroidism; liver disease, cirrhosis or acute hepatitis; reduced renal function in infants < 3 months of age; sepsis with multi-organ failure; and shock. Therapy with theophyllines should be administered cautiously in patients presenting with one or more of these risk factors, and the dosage should be appropriately reduced to prevent toxicity. More intensive monitoring of serum theophylline concentrations may be required. Toxicity is most likely to occur when levels exceed 20 mcg/mL. Severe cases, sometimes without previous warning, have led to cardiac arrhythmias, intractable seizures, and death.

Chewable products frequently may contain aspartame, which is metabolized in the gastrointestinal tract to phenylalanine. Sudafed (brand of pseudoephedrine) chewable 15 mg tablets provide the equivalent of 0.78 mg of phenylalanine per each tablet. The aspartame/phenylalanine content should be considered when this and similar products are used in patients who must restrict their intake of phenylalanine (i.e. phenylketonurics).

The use of theophyllines is associated with an increase in heart rate which may progress to supraventricular tachycardia or ventricular arrhythmia at high serum drug concentrations. Appearance of cardiac adverse effects is generally an indication of theophylline toxicity, although patients with a history of tachyarrhythmias may be more susceptible to the chronotropic effect of these drugs. Therapy with theophyllines should be administered cautiously in such patients. Caution is also advised in patients with hypertension, hyperthyroidism, angina pectoris, or recent myocardial infarction, since high dosages of the drugs are associated with positive inotropic as well as chronotropic effects. Clinical monitoring of serum drug concentrations is recommended to prevent toxicity.

Sympathomimetic agents may cause or worsen urinary difficulty in patients with prostate enlargement due to smooth muscle contraction in the bladder neck via stimulation of alpha-1 adrenergic receptors. Therapy with sympathomimetic agents should be administered cautiously in patients with hypertrophy or neoplasm of the prostate.

Certain conditions have been identified as causes of reduced theophylline clearance. They include age (neonates and infants < 1 year as well as elderly patients > 60 years) and the following concurrent diseases: acute pulmonary edema; decompensated heart failure; cor pulmonale; fever (>= 102 degrees for 24 hours or more, or lesser temperature elevations for longer periods); influenza; untreated or uncontrolled hypothyroidism; liver disease, cirrhosis or acute hepatitis; reduced renal function in infants < 3 months of age; sepsis with multi-organ failure; and shock. Therapy with theophyllines should be administered cautiously in patients presenting with one or more of these risk factors, and the dosage should be appropriately reduced to prevent toxicity. More intensive monitoring of serum theophylline concentrations may be required. Toxicity is most likely to occur when levels exceed 20 mcg/mL. Severe cases, sometimes without previous warning, have led to cardiac arrhythmias, intractable seizures, and death.

Certain conditions have been identified as causes of reduced theophylline clearance. They include age (neonates and infants < 1 year as well as elderly patients > 60 years) and the following concurrent diseases: acute pulmonary edema; decompensated heart failure; cor pulmonale; fever (>= 102 degrees for 24 hours or more, or lesser temperature elevations for longer periods); influenza; untreated or uncontrolled hypothyroidism; liver disease, cirrhosis or acute hepatitis; reduced renal function in infants < 3 months of age; sepsis with multi-organ failure; and shock. Therapy with theophyllines should be administered cautiously in patients presenting with one or more of these risk factors, and the dosage should be appropriately reduced to prevent toxicity. More intensive monitoring of serum theophylline concentrations may be required. Toxicity is most likely to occur when levels exceed 20 mcg/mL. Severe cases, sometimes without previous warning, have led to cardiac arrhythmias, intractable seizures, and death.

The use of theophyllines is associated with an increase in heart rate which may progress to supraventricular tachycardia or ventricular arrhythmia at high serum drug concentrations. Appearance of cardiac adverse effects is generally an indication of theophylline toxicity, although patients with a history of tachyarrhythmias may be more susceptible to the chronotropic effect of these drugs. Therapy with theophyllines should be administered cautiously in such patients. Caution is also advised in patients with hypertension, hyperthyroidism, angina pectoris, or recent myocardial infarction, since high dosages of the drugs are associated with positive inotropic as well as chronotropic effects. Clinical monitoring of serum drug concentrations is recommended to prevent toxicity.