Logo

OpiCalc

FavoritesSpecialtiesDrugsGuidelinesMost Used

Quick Access

Favorites
Most Used

All Specialties

OpiCalc Logo
Clinical CalculatorsDrugsGuidelines
SpecsDrugsGuides
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
‌
OpiCalc Logo

OpiCalc

Easy, fast, and private medical tools for clinicians. Always free.

No Login Required
Ready for the Bedside

Resources

About UsEditorial PolicyMedical DisclaimerPrivacy PolicyTerms of UseCookie Policy

Support

Contact Us

Clinical Notice:OpiCalc is not a substitute for professional clinical judgment. Always verify dosages and guidelines.

OpiCalc © 2018-2026

•

All Rights Reserved

Registry Hub
Bronchodilator/Discontinued

DILOR-400

DILOR-400

Clinical safety rating

caution

Comprehensive clinical and safety monograph for DILOR-400 (DILOR-400).


Mechanism of Action

Phosphodiesterase inhibitor; inhibits PDE4 and PDE5, leading to increased intracellular cAMP and cGMP, resulting in bronchodilation and vasodilation.

What the body does with it

MetabolismHepatic metabolism via CYP1A2, CYP3A4, and CYP2E1; undergoes N-demethylation and oxidation to inactive metabolites.
ExcretionRenal (70% unchanged), hepatic metabolism (30%)
Half-life3.1 hours (terminal elimination half-life; may increase in hepatic impairment or congestive heart failure)
Protein binding40% bound, primarily to albumin
Volume of Distribution0.5 L/kg (approximates total body water; indicates distribution into extracellular fluid)
BioavailabilityOral: 95-100% (well absorbed from gastrointestinal tract)
Onset of ActionOral: 15-30 minutes; Intravenous: less than 5 minutes
Duration of ActionOral: 6-8 hours; Intravenous: 4-6 hours (duration may be prolonged with sustained-release formulations)
Molecular Weight254.24

Classification & Brands

Dosing & administration

400 mg orally every 6 to 8 hours; maximum daily dose 2400 mg.

Dosage formTABLET
Renal impairmentGFR 10-50 mL/min: 400 mg every 8-12 hours; GFR <10 mL/min: 400 mg every 12-24 hours.
Liver impairmentChild-Pugh Class A: no adjustment; Child-Pugh Class B: 400 mg every 8-12 hours; Child-Pugh Class C: 400 mg every 12-24 hours.
Pediatric use6 months to 2 years: 8-12 mg/kg/day divided every 6 hours; 2-12 years: 12-16 mg/kg/day divided every 6 hours; maximum 600 mg/day.
Geriatric useStart at lower end of dosing range (400 mg every 8 hours) and titrate based on renal function and tolerability.

Use during pregnancy

1st trimesterNo human data; animal studies show no teratogenic effects at therapeutic doses. Use only if potential benefit justifies risk.
2nd trimesterNo known fetal harm reported; limited human data. Caution advised.
3rd trimesterMay inhibit uterine contractions near term; avoid use during labor. No known adverse fetal effects.

Clinical note

Comprehensive clinical and safety monograph for DILOR-400 (DILOR-400).

Placental transferCrosses placenta; maternal serum levels correlate with cord blood levels. Limited data suggest minimal accumulation in fetus.
BreastfeedingDyphylline is excreted into breast milk in small amounts. Infant plasma levels are likely low, but irritability and insomnia have been reported. Use with caution, monitoring infant for signs of xanthine toxicity.
Lactation RatingL3 (Limited data; potential adverse effects)
Teratogenic RiskTeratogenic potential: Pregnancy Category C. First trimester: Limited human data, animal studies show fetal toxicity at high doses. Second and third trimesters: Potential for transient neonatal hypoglycemia, tachycardia, and irritability due to maternal xanthine exposure. Avoid use unless benefit outweighs risk.
Fetal MonitoringMonitor maternal serum theophylline levels (if applicable, as diphylline is a theophylline derivative) to avoid toxicity. Assess fetal heart rate and growth if used chronically. Monitor neonatal for signs of xanthine toxicity (tachycardia, irritability) after delivery.
Fertility EffectsLimited data. No specific studies on fertility impact. In animal studies, no adverse effects on reproductive function at therapeutic doses. Potential for hormonal imbalance with high doses, but clinical significance unknown.

Warnings & precautions

■ FDA Black Box Warning

None.

Side Effect Profile

Serious Effects

Absolute Contraindications

Hypersensitivity to dyphylline or any xanthine derivativePeptic ulcer disease (active)Seizure disorders (unless adequately controlled with anticonvulsants)

Clinical Precautions

PrecautionsCardiovascular: May cause hypotension, tachycardia, or arrhythmias; use with caution in patients with cardiovascular disease., CNS: May cause insomnia, anxiety, or seizures; adjust dose in elderly or with hepatic impairment., Renal: Excreted largely unchanged; caution in renal impairment., Drug interactions: Increased toxicity with cimetidine, ciprofloxacin, and others that inhibit CYP1A2.
Food/DietaryAvoid high-caffeine foods (coffee, tea, cola, chocolate) as they increase risk of side effects. Charcoal-broiled foods may decrease drug absorption. High-fat meals may delay absorption; take on an empty stomach for consistent effect.

Clinical Tips & Counseling

Clinical PearlsDILOR-400 (diprophylline) is a xanthine bronchodilator with similar efficacy to theophylline but with reduced central nervous system stimulation. Monitor serum levels for therapeutic range (10-20 mcg/mL). Caution in patients with peptic ulcer disease, hyperthyroidism, or seizure disorders. Adjust dose in hepatic impairment and elderly. Avoid concurrent use with other xanthines.
Patient AdviceTake exactly as prescribed; do not exceed recommended dose. · Do not crush or chew extended-release tablets. · Report nausea, vomiting, palpitations, or seizures immediately. · Avoid caffeine-containing foods and beverages. · Do not smoke or stop smoking without consulting doctor as dose may need adjustment. · Keep a regular dosing schedule; do not double up missed doses.

DILOR-400 Interactions

Loading safety data…

This overview is compiled from peer-reviewed clinical sources and FDA labeling. It's here to support — not replace — clinical judgment. Always verify dosing against your institution's current protocols before prescribing.

On this page

Mechanism of ActionDosing & administrationUse during pregnancyWarnings & precautionsDrug interactions

Compare with

ACCURBRONAEROLATEAEROLATE IIIAEROLATE JRAEROLATE SR

External sources

DailyMed (NIH) PubMed OpenFDA