Phyllocontin
aminophylline (theophylline, ethylenediamine)
Pharmacologic class: Xanthine
Therapeutic class: Bronchodilator
Pregnancy risk category C
Action
Unclear. Thought to directly relax smooth muscle of bronchial airways and increase pulmonary blood flow by inhibiting phosphodiesterase.
Availability
Injection: 250 mg/10 ml
Oral liquid: 105 mg/5 ml
Tablets: 100 mg, 200 mg
Indications and dosages
➣ Symptomatic relief of bronchospasm in patients with acute symptoms who require rapid theophyllinization
Adults (nonsmokers): 0.7 mg/kg/hour I.V. for first 12 hours. Maintenance dosage is 0.5 mg/kg/hour I.V.
Children ages 9 to 16: 1 mg/kg/hour I.V. for first 12 hours. Maintenance dosage is 0.8 mg/kg/hour I.V.
Children ages 6 months to 9 years: 1.2 mg/kg/hour I.V. for first 12 hours. Maintenance dosage is 1 mg/kg/hour I.V.
➣ Chronic bronchial asthma
Adults and children: Dosage is highly individualized. Common initial dosage is 16 mg/kg/24 hours I.V. or 400 mg/24 hours I.V. in divided doses at 6- or 8hour intervals. If needed, dosage may be increased 25% at 3-day intervals.
Dosage adjustment
• Heart failure
• Hepatic disease
• Elderly patients
• Smokers
Off-label uses
• Dyspnea in patients with chronic obstructive pulmonary disease (COPD)
Contraindications
• Hypersensitivity to xanthine compounds or ethylenediamine
• Seizure disorders
Precautions
Use cautiously in:
• COPD, diabetes mellitus, glaucoma, renal or hepatic disease, heart failure or other cardiac or circulatory impairment, hypertension, hyperthyroidism, peptic ulcer, severe hypoxemia
• active peptic ulcer disease
• elderly patients
• neonates, infants, and young children.
Administration
• For I.V. use, dilute according to label directions and infuse at a rate no faster than 25 mg/minute.
• Don't give in I.V. solutions containing invert sugar, fructose, or fat emulsions.
• Give oral form at meals with 8 oz of water.
Adverse reactions
CNS: irritability, dizziness, nervousness, restlessness, headache, insomnia, stammering speech, abnormal behavior, mutism, unresponsiveness alternating with hyperactivity, seizures
CV: palpitations, sinus tachycardia, extrasystoles, marked hypotension, arrhythmias, circulatory failure
GI: nausea, vomiting, diarrhea, epigastric pain, hematemesis, gastroesophageal reflux, anorexia
GU: urine retention (in men with enlarged prostate), diuresis, increased excretion of renal tubular cells and red blood cells, proteinuria
Metabolic: hyperglycemia
Musculoskeletal: muscle twitching
Respiratory: tachypnea, respiratory arrest
Skin: flushing
Other: fever, hypersensitivity reactions (including exfoliative dermatitis and urticaria)
Interactions
Drug-drug. Adenosine: decreased antiarrhythmic effect of adenosine
Barbiturates, nicotine, phenytoin, rifampin: decreased aminophylline blood level
Beta-adrenergic blockers: antagonism of aminophylline effects
Calcium channel blockers, cimetidine, ciprofloxacin, disulfiram, erythromycin, hormonal contraceptives, influenza vaccine, interferon, methotrexate: elevated aminophylline blood level
Carbamazepine, isoniazid, loop diuretics (such as furosemide): increased or decreased aminophylline blood level
Ephedrine, other sympathomimetics: toxicity, arrhythmias
Lithium: increased lithium excretion
Drug-diagnostic tests. Aspartate aminotransferase, glucose: increased levels
Drug-herbs. Cayenne: increased risk of aminophylline toxicity
Drug-behaviors. Smoking: increased aminophylline elimination
Patient monitoring
See Monitor aminophylline blood level. Adjust dosage if patient has signs or symptoms of toxicity (tachycardia, headache, anorexia, nausea, vomiting, diarrhea, restlessness, and irritability).
• Assess for arrhythmias, especially after giving loading dose.
• Check vital signs and fluid intake and output.
• Monitor patient's response to drug, and assess pulmonary function test results.
Patient teaching
• Advise patient to take oral doses at meals with 8 oz of water.
• Caution patient to avoid driving and other hazardous activities until he knows how drug affects concentration and alertness.
• Tell patient to minimize GI upset by eating small, frequent servings of food and drinking plenty of fluids.
• Advise patient to establish effective bedtime routine to minimize insomnia.
• Caution patient not to change aminophylline brands.
• If patient smokes, tell him to notify prescriber if he stops smoking; dosage may need to be adjusted.
• As appropriate, review all other significant and life-threatening adverse reactions and interactions, especially those related to the drugs, tests, herbs, and behaviors mentioned above.
aminophylline
(am-in-off-i-lin) aminophylline,Phyllocontin
(trade name)Classification
Therapeutic: bronchodilatorsPharmacologic: xanthines
Indications
Action
- Bronchodilation,
- CNS stimulation,
- Positive inotropic and chronotropic effects,
- Diuresis,
- Gastric acid secretion. Aminophylline is a salt of theophylline and releases free theophylline after administration.
Therapeutic effects
Pharmacokinetics
Time/action profile (bronchodilation)
| ROUTE | ONSET† | PEAK | DURATION |
|---|---|---|---|
| IV | rapid | end of infusion | 6–8 hr |
Contraindications/Precautions
Adverse Reactions/Side Effects
Central nervous system
- seizures (life-threatening)
- anxiety (most frequent)
- headache
- insomnia
- irritability
Cardiovascular
- arrhythmias (life-threatening)
- tachycardia (most frequent)
- angina
- palpitations
Dermatologic
- rash
Gastrointestinal
- nausea (most frequent)
- vomiting (most frequent)
- anorexia
Neurologic
- tremor
Interactions
Drug-Drug interaction
Additive CV and CNS side effects with adrenergics (sympathomimetic).May ↓ the therapeutic effect of lithium and phenytoin.Smoking, barbiturates, carbamazepine, phenytoin, nevirapine and rifampin may ↑ metabolism and may ↓ effectiveness.Erythromycin, beta blockers, clarithromycin, calcium channel blockerscimetidine,hormonal contraceptives, disulfiram, doxycycline, estrogens, fluvoxamine, isoniazid, ketoconazole, mexiletine, nefazodone, protease inhibitors, quinidine, some fluoroquinolones, and large doses of allopurinol ↓ metabolism and may lead to toxicity.Caffeine-containing herbs (cola nut, guarana, mate, tea, coffee) may ↑ serum levels and risk of CNS and CV side effects.↓ serum levels and effectiveness with St. John’s wort.Excessive regular intake of charcoal-broiled foods may ↓ effectiveness.Route/Dosage
Dose should be determined by theophylline serum level monitoring. Loading dose should be decreased or eliminated if theophylline preparation has been used in preceding 24 hr. Aminophylline is 80% theophylline (100 mg aminophylline = 80 mg theophylline).Availability (generic available)
Nursing implications
Nursing assessment
- Assess BP, pulse, respiratory status (rate, lung sounds, use of accessory muscles, number and severity of apnea spells in infants) before and throughout therapy. Ensure that oxygen therapy is correctly instituted during acute asthma attacks.
- Monitor intake and output ratios for an increase in diuresis or fluid overload.
- Monitor patients with a history of cardiovascular problems for chest pain and ECG changes (PACs, supraventricular tachycardia, PVCs, ventricular tachycardia). Resuscitative equipment should be readily available.
- Monitor pulmonary function tests before and periodically during therapy to determine therapeutic efficacy in patients with chronic bronchitis or emphysema.
- Lab Test Considerations: Monitor ABGs, acid-base, and fluid and electrolyte balance in patients receiving parenteral therapy or whenever required by patient’s condition. Monitor drug levels routinely, especially in patients requiring high doses or during prolonged intensive therapy. Serum sample should be obtained at time of peak absorption. Peak levels should be evaluated 30 min after a 30 min IV loading dose, 12–24 hr after initiation of a continuous infusion and 1–2 hr after rapid-acting oral forms, and 4–12 hr after extended-release oral forms. Therapeutic plasma levels range from 10–15 mcg/mL for asthma and 6–14 mcg/mL for apnea of prematurity. Drug levels in excess of 20 mcg/mL are associated with toxicity. Caffeine ingestion may falsely elevate drug concentration levels.
- Observe for symptoms of drug toxicity (anorexia, nausea, vomiting, stomach cramps, diarrhea, confusion, headache, restlessness, flushing, increased urination, insomnia, tachycardia, arrhythmias, seizures). Notify health care professional immediately if these occur. Tachycardia, ventricular arrhythmias, or seizures may be the first sign of toxicity.
- Geriatric: Patients over 60 yr have ↑ risk of toxicity and sensitivity to toxic effects due to age-related pharmacodynamic and pharmacokinetic changes. Assess frequently.
Potential Nursing Diagnoses
Ineffective airway clearance (Indications)Activity intolerance (Indications)
Implementation
- Administer around the clock to maintain therapeutic plasma levels.
Intravenous Administration
- pH: 8.6–9.0.
- Intravenous: Diluent: May be diluted in D5W, D10W, D20W, 0.9% NaCl, 0.45% NaCl, D5/0.9% NaCl, D5/0.45% NaCl, D5/0.25% NaCl, or LR. Concentration: 1 mg/mL. Maximum concentrationis 25 mg/mL. Mixture is stable for 24 hr if refrigerated.
- Do not administer discolored or precipitated solution. Flush main IV line before administration.
- If extravasation occurs, local injection of 1% procaine and application of heat may relieve pain and promote vasodilation.
- Loading Dose: Administer over 20–30 min.
- Rate: Do not exceed 20–25 mg/min in adults or 0.36 mg/kg/min in children. Administer via infusion pump to ensure accurate dosage. Rapid administration may cause chest pain, dizziness, hypotension, tachypnea, flushing, arrhythmias, or a reaction to the solution or administration technique (chills; fever; redness, pain, or swelling at injection site).
- Continuous Infusion: Usually given as a loading dose in a small volume followed by continuous infusion in larger volume.
- Rate: See Route and Dosage section for rates.
- Y-Site Compatibility: acyclovir, alemtuzumab, alfentanil, allopurinol, amifostine, amikacin, amphotericin B cholesteryl, amphotericin B lipid complex, amphotericin B liposome, anidulafungin, argatroban, atropine, azithromycin, aztreonam, benztropine, bivalirudin, bleomycin, bumetanide, butorphanol, calcium chloride, calcium gluconate, carboplatin, carmustine, caspofungin, cefazolin, cefoperazone, cefotaxime, cefotetan, cefoxitin, ceftazidime, ceftriaxsone, cefuroxime, chloramphenicol, cisplatin, cladribine, clindamycin, clonidine, cyanocobalamin, cyclosphophamide, cyclosporine, cytarabine, dactinomycin, daptomycin, dexamethasone, dexmedetimodine, digoxin, docetaxel, dopamine, doripenem, doxacurium, doxorubicin liposome, doxycycline, enalaprilat, epinephrine, epoetin alfa, eptifibatide, ertapenem, erythromycin, esmolol, etoposide, etoposide phosphate, famotidine, fentanyl, filgrastim, fluconazole, fludarabine, fluorouracil, folic acid, foscarnet, furosemide, gemcitabine, gentamicin, glycopyrrolate, granisetron, heparin, hetastarch, hydrocotisone, hydromorphone, ifosfamide, indomethacin, insulin, irinotecan, ketorolac, labetalol, leucovorin, levofloxacin, lidocaine, linezolid, lorazepam, mannitol, mechlorethamine, melphalan, meperidine, meropenem, metaraminol, methotrexate, methyldopate, methylprednisolone, metoclopramide, metoprolol, metronidazole, micafungin, milrinone, mitoxantrone, morphine, multivitamins, nafcillin, nalbuphine, naltrexone, nesiritide, nitroglycerin, nitroprusside, octreotide, oxacillin, oxytocin, paclitaxel, palonosetron, pamidronate, pancuronium, pantoprazole, permetrexed, pentobarbital, phenobarbital, phentolamine, phenylephrine, phytonadione, piperacillin/tazobactam, potassium acetate, potassium chloride, procainamide, propofol, propranolol, protamine, pyridoxime, ranitidine, remifentanil, rituximab, rocuronium, sargramostim, sodium acetate, sodium bicarbonate, streptokinase, succinylcholine, sufentanil, tacrolimus, teniposide, theophylline, thiotepa, ticarcillin/clavulanate, tigecycline, tirofiban, tobramycin, tolazoline, trastuzumab, trimetaphan, vasopressin, vecuronium, vincristine, vitamin B complex with vitamin C, voriconazole, zolendronic acid
- Y-Site Incompatibility: amiodarone, ampicillin, ascorbic acid, atracurium, buprenorphine, chlorpromazine, ciprofloxacin, dantrolene, dexrazoxane, diazepam, diazoxide, diphenhydramine, dobutamine, doxorubicin, epinephrine, epirubicin, ganciclovir, haloperidol, hydralazine, hydroxyzine, idarubicin, isoproterenol, magnesium sulfate, midazolam, minocycline, mycophenolate, norepinephrine, ondansetron, papaverine, penicillin G, pentamidine, pentazocine, phenytoin, prochlorperazine, promethazine, quinupristin/dalfopristin, thiamine, trimethoprim/sulfamethoxazole, vancomycin, verapamil, vinorelbine, warfarin
- Additive Incompatibility: Admixing is not recommended because of dose titration and incompatibilities.
Patient/Family Teaching
- Encourage the patient to drink adequate liquids (2000 mL/day minimum) to decrease the viscosity of the airway secretions.
- Advise patient to avoid OTC cough, cold, or breathing preparations without consulting health care professional. These medications may increase side effects and cause arrhythmias.
- Encourage patients not to smoke. A change in smoking habits may necessitate a change in dose.
- Advise patient to minimize intake of xanthine-containing foods or beverages (colas, coffee, chocolate) and not to eat charcoal-broiled foods daily.
Evaluation/Desired Outcomes
- Increased ease in breathing.
- Clearing of lung fields on auscultation.
- Respiratory and myocardial stimulation in apnea of infancy.