DrugindexOnline^{2nd edition}

Pronouncation: (DIE-fih-lin)
Class: Xanthine derivative

Trade Names:
Lufyllin
- Tablets 200 mg
- Tablets 400 mg

Trade Names:
Dylix
- Elixir 100 mg per 15 mL

Mechanism of Action

Pharmacology

Relaxes bronchial smooth muscle and stimulates central respiratory drive.

Pharmacokinetics

Absorption

Rapidly absorbed, reaching a mean C _max of 17.1 mcg/mL in about 45 min.

Metabolism

Not metabolized.

Elimination

Unchanged by the kidney. Elimination t _½ is approximately 2 h.

Indications and Usage

Relief of acute bronchial asthma and reversible bronchospasm associated with chronic bronchitis and emphysema.

Contraindications

Hypersensitivity to any component of the product or related xanthine compounds.

Dosage and Administration

Adult

PO Usual dose up to 15 mg/kg every 6 h. Elixir: 200 to 400 mg (2 to 4 Tbsp) every 6 h. Dose should be titrated to severity of condition and response of patient. Measure and administer prescribed dose of elixir using dosing syringe, dosing spoon, or dosing cup.

Storage/Stability

Store tablets and elixir at controlled room temperature (59° to 86°F). Store Lufyllin tablets between 68° and 77°F.

Drug Interactions

Probenecid

May increase the plasma t _½ of dyphylline.

Sympathomimetic bronchodilators

Synergistic pharmacologic effect may occur.

Laboratory Test Interactions

None well documented.

Adverse Reactions

Cardiovascular

Circulatory failure; extrasystoles; flushing; hypotension; palpitation; tachycardia; ventricular arrhythmias.

CNS

Agitation; CNS stimulation; generalized clonic and tonic convulsions; headache; hyperexcitability; insomnia; irritability; muscle twitching; restlessness.

GI

Diarrhea; epigastric pain; hematemesis; nausea; vomiting.

Metabolic

Dehydration; hyperglycemia; inappropriate antidiuretic hormone syndrome.

Renal

Albuminuria; diuresis; gross and microscopic hematuria; increased excretion of renal tubule and red blood cells.

Respiratory

Respiratory arrest; tachypnea.

Miscellaneous

Fever.

Precautions

Monitor Note frequency and severity of asthma attacks.

Pregnancy

Category C .

Lactation

Excreted in breast milk.

Children

Safety and efficacy have not been established.

Elderly

Use with caution (usually starting at the low end of the dosage range) because of the greater frequency of decreased hepatic, renal, or cardiac function, and concomitant diseases or other drug therapy.

Renal Function

Cl is reduced in patients with impaired renal function; make appropriate dosage adjustments.

Special Risk Patients

Use with caution in patients with severe cardiac disease, hypertension, hyperthyroidism, acute myocardial injury, or peptic ulcer.

Xanthine products

Ensure other xanthine products (eg, theophylline) are not being administered concurrently with dyphylline.

Overdosage

Symptoms

Agitation, anorexia, cardiac arrhythmias, CV collapse, death, dehydration, diaphoresis, diarrhea, excessive thirst, extrasystoles, fasciculation, generalized clonic and tonic convulsions, headache, hyperreflexia, hyperthermia, insomnia, irritability, nausea, nervousness, restlessness, seizures, severe vomiting, tachycardia, tinnitus, vomiting.

Patient Information

• Advise patient to take prescribed dose every 6 h without regard to meals but to take with food if stomach upset occurs.
• Advise patient or caregiver using elixir to measure and administer prescribed dose using dosing syringe, dosing spoon, or dosing cup.
• Advise patient if a dose is missed to take the dose as soon as remembered. However, if it is less than 3 h before the next scheduled dose, advise patient to skip the missed dose and take the next dose at the regularly scheduled time. Caution patient not to double the dose to catch up.
• Instruct patient not to stop the medication once symptoms have been controlled and that continued daily use is necessary to continue to control symptoms.
• Advise patient not to change the dose or stop using unless advised by health care provider.
• Advise patient that medication does not replace controller medications (eg, inhaled or oral corticosteroids) and to continue daily use of controller medications as prescribed by health care provider.
• Caution patient not to increase dose and to inform health care provider if asthma symptoms do not improve or worsen, if a more short-acting bronchodilator than usual is needed, or if the short-acting bronchodilator appears to become less effective.
• Advise patient to carry medical identification (eg, card, bracelet) if experiencing acute severe asthma attacks requiring rapid systemic treatment.
• Advise patient or caregiver to promptly report any of the following to health care provider: anxiety, nervousness, or restlessness; persistent nausea, vomiting, or diarrhea; fainting spells or lightheadedness; fast or irregular heartbeat; pounding in the chest; flushing of the face; seizures (convulsions); skin rash, itching, or hives; tremor; unusual weakness or tiredness.