Loading Dose Calculator
Calculate the loading dose required to rapidly achieve target drug concentration based on volume of distribution and bioavailability.
Important Health Disclaimer
This calculator provides general health information based on standard medical formulas and WHO guidelines. Results are for informational and educational purposes only and should not be considered as professional medical advice, diagnosis, or treatment recommendations.
For health concerns, medical conditions, fitness plans, or dietary decisions, please consult with qualified healthcare professionals, licensed physicians, registered dietitians, or certified fitness trainers who can evaluate your individual health status and medical history.
Individual health needs vary significantly. These calculations are general estimates and may not be appropriate for everyone, especially those with existing medical conditions, pregnant women, children, or elderly individuals.
Not a substitute for professional medical advice
Patient & Drug Parameters
Desired plasma concentration
100% for IV, varies for oral (e.g., 80-90% for many drugs)
Fraction of drug that is active (e.g., 0.8 for phenytoin sodium)
Loading Dose
490.0 mg
7.00 mg/kg
Formula
Loading Dose = (Cp × Vd) / (F × S)
Where Cp = target concentration, Vd = volume of distribution, F = bioavailability, S = salt factor
Clinical Note
Loading doses should be given with caution. Consider patient factors such as organ function, age, and drug interactions. Consult drug references for specific recommendations.
Common Drug Parameters
| Drug | Vd (L/kg) | Bioavailability | Salt Factor |
|---|---|---|---|
| Digoxin | 5-7 | 70-80% | 1.0 |
| Phenytoin | 0.6-0.7 | 90% | 0.92 (sodium) |
| Theophylline | 0.5 | 96% | 1.0 |
| Vancomycin | 0.4-1.0 | 100% (IV) | 1.0 |
| Aminoglycosides | 0.25-0.3 | 100% (IV) | 1.0 |
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