LUFYLLIN
Clinical safety rating: caution
Comprehensive clinical and safety monograph for LUFYLLIN (LUFYLLIN).
LUFYLLIN (dyphylline) is a xanthine bronchodilator that inhibits phosphodiesterase, increasing intracellular cAMP levels, leading to relaxation of bronchial smooth muscle and suppression of airway hyperresponsiveness. It also antagonizes adenosine receptors.
| Metabolism | Dyphylline is not metabolized by the liver; it is primarily excreted unchanged by the kidneys. Approximately 80% is eliminated unchanged in urine. |
| Excretion | Primarily renal excretion of unchanged drug and metabolites. Approximately 50% is excreted unchanged in urine, with the remainder as metabolites (including 7-hydroxypropyltheophylline and 1,3-dimethyluric acid). Biliary/fecal elimination accounts for <10%. |
| Half-life | 6-8 hours in adults with normal hepatic and renal function. In neonates, half-life is prolonged to 20-30 hours. In patients with hepatic cirrhosis, half-life may extend to 20-30 hours. In congestive heart failure, half-life is prolonged to 12-20 hours. |
| Protein binding | Approximately 40-50% bound to plasma proteins, primarily albumin. |
| Volume of Distribution | 0.5-0.7 L/kg. This indicates distribution into total body water with some tissue binding. |
| Bioavailability | Oral immediate-release: 90-100%. Rectal: approximately 80-90%. Sustained-release: 70-90% with delayed absorption. |
| Onset of Action | Oral: 30-60 minutes. Intravenous: 3-5 minutes. |
| Duration of Action | Oral: 4-6 hours (immediate-release). Intravenous: 4-6 hours. Sustained-release preparations may provide 8-12 hours of action. |
200-400 mg orally 3-4 times daily, not to exceed 1600 mg/day. Also available as 200 mg/mL injection, administer 200-400 mg IM or slow IV every 6-8 hours.
| Dosage form | TABLET |
| Renal impairment | CrCl 30-50 mL/min: administer 50-75% of normal dose. CrCl <30 mL/min: administer 25-50% of normal dose. Consider monitoring theophylline levels. |
| Liver impairment | Child-Pugh A: no adjustment. Child-Pugh B: administer 50% of normal dose. Child-Pugh C: avoid use or administer 25% of normal dose with close monitoring. |
| Pediatric use | Children <1 year: 100-200 mg/day in 3-4 divided doses. Children 1-9 years: 200-300 mg/day in 3-4 divided doses. Children 9-16 years: 200-400 mg/day in 3-4 divided doses. Weight-based alternative: 10-20 mg/kg/day in 3-4 divided doses. |
| Geriatric use | Initiate at lower end of dosing range (200 mg 3 times daily). Monitor theophylline levels and adjust dose to maintain trough concentration of 5-15 mcg/mL. Reduce dose if concurrent medications affecting hepatic metabolism. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for LUFYLLIN (LUFYLLIN).
| Breastfeeding | Dyphylline is excreted into breast milk in small amounts. The milk-to-plasma ratio is approximately 0.7. Estimated infant dose is about 1-2% of maternal weight-adjusted dose. No adverse effects reported in breastfed infants. However, monitor for signs of irritability or sleep disturbances. |
| Teratogenic Risk | Lufyllin (dyphylline) is a xanthine derivative bronchodilator. Animal studies have not demonstrated teratogenicity. Human data are limited; however, as a methylxanthine, risks are considered low. First trimester: No evidence of major malformations. Second and third trimesters: No known fetal harm, but high doses may cause transient neonatal tachycardia or irritability due to placental transfer. Avoid use near term if possible due to potential neonatal effects. |
■ FDA Black Box Warning
No FDA black box warning.
| Serious Effects |
Hypersensitivity to dyphylline or any xanthine derivative. Uncontrolled arrhythmias. Active seizure disorder. Severe hypotension. Concurrent use with other xanthines (e.g., theophylline).
| Precautions | Use with caution in patients with peptic ulcer disease, hyperthyroidism, hypertension, cardiac arrhythmias, or seizure disorders. Monitor serum levels for toxicity. Risk of ventricular arrhythmias or seizures at high doses. |
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| Fetal Monitoring | Monitor maternal serum theophylline/dyphylline levels if using high doses or prolonged therapy. Assess maternal heart rate and signs of toxicity (nausea, tachycardia, palpitations). For fetus: Monitor fetal heart rate variability if using near term. Neonatal monitoring for jitteriness, tachycardia, or feeding difficulties after delivery. |
| Fertility Effects | No known adverse effects on fertility in humans or animals. Methylxanthines have not demonstrated significant impairment of reproductive function. |