Alternative to Sodium Bicarbonate for TCA Poisoning

Today’s pearl is about an alternative to sodium bicarbonate for tricyclic antidepressant poisoning.

Sodium bicarbonate has been on and off shortage for the past few years.

• The American Society of Health-System Pharmacists (ASHP) has a great resource center for drug shortage.
• It may actually be the sodium that is the most important factor in reversing ECG findings from TCA poisoning and some other sodium channel blockers, as opposed to pH manipulation (theoretical benefit).
  • Consider administering hypertonic saline (McKinney 2003; McCabe 1998).

• One amp/syringe (50 mL) of 8.4% sodium bicarbonate contains the same amount of sodium as 97 mL of 3% sodium chloride or 38 mL of 7.5% sodium chloride*
  • A central line is recommended if giving > 3% hypertonic saline

So, 100 mL of 3% sodium chloride has the same sodium content as one amp of sodium bicarbonate. Nice easy math to remember in a critical resuscitation.

*Central line preferred

^#6

Author: Bryan D. Hayes, PharmD

Attending Pharmacist, Emergency Medicine and Toxicology, Massachusetts General Hospital; Assistant Professor of EM, Harvard Medical School View all posts by Bryan D. Hayes, PharmD