TCA Toxicity: QRS Risk & Bicarbonate Target
Tricyclic-antidepressant sodium-bicarbonate threshold: flags QRS >= 100 ms seizure/arrhythmia risk and computes the 1-2 mEq/kg bicarbonate bolus from weight.
Open the calculator → Runs in your browser. Data leaves only if you deliberately send a problem report from the interactive tool.
Example
- QRS duration
- 120
- Body weight
- 70
Result: QRS 120 ms (>= 100 ms): seizure risk -- give sodium bicarbonate 1-2 mEq/kg = 70-140 mEq, target serum pH 7.45-7.55.
The tool opens with these values already filled in. Replace them with your own.
What the result means
- QRS thresholds
- QRS >= 100 ms predicts seizures; QRS >= 160 ms predicts ventricular arrhythmias after an acute TCA overdose.
- Bicarbonate
- sodium bicarbonate 1-2 mEq/kg, target serum pH 7.45-7.55. Confirm against your institutional protocol and a second check.
What you enter
- QRS duration (ms)
- Body weight (kg)
How this is calculated
Boehnert MT, Lovejoy FH Jr. Value of the QRS duration versus the serum drug level in predicting seizures and ventricular arrhythmias after an acute overdose of tricyclic antidepressants. N Engl J Med. 1985;313(8):474-479. Read the source ↗
A reference and educational tool. Not medical, legal, or financial advice, and not a substitute for clinician judgment.