DYPHYLLINE
| DYPHYLLINE (dye'fi-lin) Dilor, Lufyllin, Protophylline  Classifications: bronchodilator; respiratory smooth muscle relaxant; xanthine; Therapeutic: bronchodilator Prototype: Theophylline Pregnancy Category: C |
Availability
200 mg, 400 mg tablets
Action
Xanthine and derivative of theophylline that results in bronchodilation, myocardial stimulation, and smooth muscle relaxation. Unlike other xanthines, dyphylline is not metabolized to theophylline in body; therefore serum theophylline levels are not useful.
Therapeutic Effect
Drug has bronchodilator effects.
Uses
Acute bronchial asthma and reversible bronchospasm associated with chronic bronchitis and emphysema.
Contraindications
Hypersensitivity to xanthine compounds; apnea in newborns; pregnancy (category C); children ≤6 y.
Cautious Use
Severe cardiac disease, hypertension, acute myocardial injury; renal or hepatic dysfunction; glaucoma; seizure disorders; hyperthyroidism; peptic ulcer; in the older adults or children; concomitant administration of other xanthine formulations or other CNS-stimulating drugs; lactation.
Route & Dosage
| Asthma Adult: PO 200–800 mg q6h up to 15 mg/kg q.i.d. Child (≥6 y): PO 4.4–6.6 mg/kg/d in divided doses |
Administration
Oral- Give oral preparation with a full glass of water on an empty stomach (e.g., 1 h before or 2 h after meals) to enhance absorption. However, administration after meals may help to relieve gastric discomfort.
- Exercise care in the amount of elixir given to children because it has a high alcohol content (18–20%).
Adverse Effects (≥1%)
CNS: Headache, irritability, restlessness, dizziness, insomnia, light-headedness, muscle twitching, convulsions. CV: Palpitation, tachycardia, extrasystoles, flushing, hypotension. GI: Nausea, vomiting, diarrhea, anorexia, epigastric distress. Respiratory: Tachypnea. Other: Albuminuria, fever, dehydration.Interactions
Drug: beta blockers may antagonize bronchodilating effects of dyphylline; halothane increases risk of cardiac arrhythmias; probenecid may decrease dyphylline elimination.Pharmacokinetics
Absorption: Readily absorbed from GI tract. Peak: 1 h. Metabolism: In liver (but not to theophylline). Elimination: In urine. Half-Life: 2 h.Nursing Implications
Assessment & Drug Effects
- Lab tests: Baseline and periodic pulmonary function tests to assess therapeutic effectiveness.
- Monitor therapeutic effectiveness; usually occurs at a blood level of at least 12 mcg/mL.
- Note: Toxic dyphylline plasma levels, although rare with normal dosage, are a risk in patients with a diminished capacity for dyphylline clearance (e.g., those with CHF or hepatic impairment or who are >55 y or <1 y of age).
Patient & Family Education
- Take medication consistently with or without food at the same time each day.
- Notify physician of adverse effects: Nausea, vomiting, insomnia, jitteriness, headache, rash, severe GI pain, restlessness, convulsions, or irregular heartbeat.
- Avoid alcohol and also large amounts of coffee and other xanthine-containing beverages (e.g., tea, cocoa, cola) during therapy.
- Consult physician before taking OTC preparations. Many OTC drugs for coughs, colds, and allergies contain ephedrine or other sympathomimetics and xanthines (e.g., caffeine, theophylline, aminophylline).
Common adverse effects in italic, life-threatening effects underlined; generic names in bold; classifications in SMALL CAPS; Canadian drug name; 
Prototype drug