| Enter Age (years) down to 1
year of age. |
|
| Enter Height in |
|
| Enter Actual Weight in
|
|
| Select Sex |
|
| Enter Most Recent
Serum Creatinine (mg/dl) |
|
Enter Previous Serum
Creatinine (mg/dl)
Use the same value twice if
renal function is stable. |
|
| Enter time between serum
creatinines (hours). Use 24 if renal function is stable.
Creatinines should be > 1 T1/2 apart
to accurately determine creatinine clearance when renal function is
changing. |
|
|
The factors below are known to
clinically impact the kinetics of theophylline. When more than one
factor is present the values in decimal format are multiplied to
obtain a final result. If you wish to be conservative when multiple drug interactions are present
select one factor that is present that increases clearance
the most and one factor that is present
which decreases clearance the most.
Other significant interactions:
Decease
clearance:
Increase clearance: |
|
| Smoking History (clearance
increased 60%) |
|
| CHF (clearance decrease
60%) |
|
| Cystic Fibrosis (clearance
increase 50%) |
|
| Acute Pulmonary
Edema (clearance decreased 50%) |
|
| Acute Viral
Illness (clearance decrease 50%) |
|
| Hepatic
Cirrhosis (clearance increase 50%) |
|
| Severe Obstructive
Pulmonary Disease (clearance decrease 20%) |
|
| Cimetidine (clearance
decrease 40%) |
|
| Ciprofloxacin (clearance decrease 30%) |
|
| Erythromycin (clearance decrease 25%) |
|
| Influenza Vaccine (clearance
decreased 50%) |
|
| Phenobarbital (clearance
increase 30%) |
|
| Phenytoin (clearance
increase 60%) |
|
| Propranolol (clearance
decrease 40%) |
|
| Rifampin (clearance
increase 30%) |
|
Select Fraction of
Administered Dose that is active ingredient (Theophylline)
Aminophylline=0.84, Aminodur =0.84,
Choledyl=0.64, Theophylline & Others= 1
|
|
| Select Dosage Form
(bioavailability=1) |
|
| Select Drug |
|
| |
|
| Calculated Lean Body Weight
(kg) |
|
| Calculated Drug Dosing
Weight (kg) |
|
| Calculated Creatinine
Clearance (ml/min) |
|
| Calculated T1/2 for
CREATININE (hours) |
|
| Calculated Drug K
(hours-1) |
|
| Calculated Drug T1/2
(hours) |
|
| Calculated Drug Vd
(liters) |
|
| Calculated Drug Clearance
(liters/hour) |
|
Calculated Loading Dose
(mg)
For
level of 10 mcg/ml based on Dosing Weight assuming no
drug on board |
|
Calculated Total Daily Dose
(mg)
For average level of 10 mcg/ml based
on Dosing Weight |
|
Calculated Hourly Dose (mg)
For average level of 10 mcg/ml based
on Dosing Weight |
|
| Enter Rounded Dose (mg) |
|
| Select Dosage Interval |
|
| |
|
| The brochodilator
effect of theophylline is proportional to the logarithm of the serum
concentration over the range 5-20 mcg/ml. |
|
|
Calculated Peak (mcg/ml)
Maximum Peak 20 mcg/ml |
|
|
Calculated Trough (mcq/ml)
Usual Goal 5-15 mcg/ml |
|
| Calculated Average level
(mcg/ml) |
|
| Serum level
analysis: Please complete the input boxes below if you have
an actual level and the time is was drawn. These values along with
the entered dosage history and dosage form will be used to
calculated the patient's elimination rate constant (K) and clearance. |
|
Enter Actual Measured
Steady State Level mcq/ml.
Troughs are recommended. For unevenly spaced dosing
intervals, levels are assumed to be drawn before the first dose of the day. For
continuous infusions levels can be drawn anytime once steady steady is
acheived.
Serum levels are recommended
daily for critically ill hospitalized patients and after 3-5
half-lives of starting therapy or dosage adjustment for others. |
|
| Enter the time in
hours that the level was drawn after the PREVIOUS DOSE.
For unevenly spaced dosing intervals
levels are assumed to be drawn before the
first dose of the day. Use any time except for 0 for continuous
infusions. |
|
| |
|
| K (hours-1) Fit (Fit using
level, time of level, dosage form, and entered dosage history.) |
|
| Thanks for using the program. If you
have any comments, suggestions or questions please contact the author. |
|