LUFYLLIN
Clinical safety rating
cautionComprehensive 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. |
| Molecular Weight | 238.25 |
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 | Limited data; no known teratogenicity in animals, but caution advised. |
| 2nd trimester | Use only if clearly needed; monitor maternal respiratory status. |
| 3rd trimester | May cause fetal tachycardia; avoid near term. |
Clinical note
Comprehensive clinical and safety monograph for LUFYLLIN (LUFYLLIN).
| Placental transfer | Crosses placenta; fetal serum levels 10-50% of maternal levels. |
| Breastfeeding | Excreted into breast milk in low amounts; potential for irritability and sleep disturbance in infant. |
| Lactation Rating | L2 (Safer) |
| 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. |
| 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. |
■ FDA Black Box Warning
No FDA black box warning.
| Serious Effects |
Hypersensitivity to dyphyllineAcute myocardial infarctionPeptic ulcer diseaseUncontrolled seizure disorders
| 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. |
| Food/Dietary | Avoid large amounts of caffeine-containing foods and beverages (coffee, tea, cola, chocolate) as they may increase adverse effects like nervousness and palpitations. No significant food interactions other than caffeine. Alcohol may increase CNS stimulation. |
| Clinical Pearls | Dyphylline (Lufyllin) is a xanthine bronchodilator that is not metabolized to theophylline, making it an alternative for patients who cannot tolerate theophylline. It is 2-3 times less potent than theophylline, requiring higher doses. Renal excretion is the primary elimination route; dose adjustment is needed in renal impairment. Monitor drug interactions with cimetidine, quinolones, and macrolides, though less severe than with theophylline. Use with caution in patients with peptic ulcer, hyperthyroidism, or seizure disorders. Therapeutic levels are not well-defined, but target 6-18 mcg/mL for theophylline equivalents. |
| Patient Advice | Take this medication exactly as prescribed, do not double doses if missed. · Avoid excessive caffeine intake (coffee, tea, cola, chocolate) as it may increase side effects. · Report any signs of toxicity such as nausea, vomiting, insomnia, anxiety, or palpitations. · Do not crush or chew extended-release tablets unless instructed. · Maintain adequate hydration to help prevent side effects. · Inform your doctor if you are pregnant, breastfeeding, or have liver, kidney, or heart disease. |
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