Dyphylline Dosing for a 41kg Adult
For a 41kg adult, administer dyphylline at 15 mg/kg per dose, which equals approximately 615 mg per dose, given twice daily (BID), with a maximum single dose not exceeding 1000 mg.
Dosing Calculation and Administration
The standard adult dosing for dyphylline is 15 mg/kg per dose administered twice daily, which for a 41kg patient calculates to approximately 615 mg per dose 1, 2.
Dyphylline can be administered via oral tablet, oral solution, or intramuscular injection with equivalent bioavailability, as absorption is rapid and independent of route or formulation 1, 2.
The dosing interval should be every 12 hours (BID) due to dyphylline's short half-life of approximately 2.1-2.6 hours 1, 2.
Pharmacokinetic Considerations
Dyphylline reaches peak serum concentration (Cmax) rapidly: within 20-40 minutes for oral solutions and approximately 40 minutes for tablets 2.
The drug has a volume of distribution of approximately 0.5 L/kg and total body clearance of 0.11 L/kg/hr, which supports the twice-daily dosing regimen 3.
Unlike theophylline, dyphylline does not require routine plasma monitoring except in patients with hepatic insufficiency or documented intolerance to xanthine drugs 4.
Maximum Dosing and Safety
The maximum recommended single dose is 1000 mg, even though this patient's calculated dose (615 mg) falls well below this threshold 4.
Dyphylline produces stable serum concentrations and has a significantly better side effect profile compared to theophylline, with only 5% of patients reporting moderate adverse effects in retrospective studies 4.
Important Clinical Caveats
Dyphylline has a narrow evidence base for proven efficacy, and current dosage recommendations have been questioned in the literature due to its short half-life 1.
Bioavailability is consistent across formulations (solution, regular tablet, sustained-release), so formulation choice can be based on patient preference and availability 2.
In lactating women, dyphylline distributes into breast milk at twice the serum concentration (milk/serum ratio of 2.08), which is a consideration if applicable 3.