Clinical scenario

A 27 year old woman attends the emergency department with a suspected amitrptyline overdose. She has a Glasgow Coma Scale score of 7, is trypsilating, and has a broad complex tachycardia with a blood pressure of 70/30. After intubation and ventilation and sodium bicarbonate she remains tachycardic at 130 although her complexes have narrowed somewhat and her blood pressure is still low at 80/40. You have heard that tricyclic overdoses may respond to glucagon and wonder whether there is any evidence for this.

Three part question

In [overdose with tricyclic antidepressants] does [the addition of glucagon to standard treatments] improve [clinical outcome]?

Search strategy

Medline 1966–02/03 using the OVID interface. [(exp antidepressive agents OR exp antidepressive agents, tricyclic OR exp desipramine OR exp amitriptyline OR tricyc$.af. OR amitriptyline.af. OR amoxapine.af. OR clomipramine.af. OR doxepin.af. OR dothiepin.af. OR imipramine.af. OR lofepramine.af. OR nortriptyline.af. OR trimipramine.af.) AND (exp glucagon OR glucagon.af.)] LIMIT to human AND English.

Search outcome

Altogether 31 papers found, 28 failed to answer the three part question, the three relevant papers are case reports summarised in table 2.

Comment(s)

Although all three patients received multiple treatments the authors state the improvement in condition was immediately after high dose glucagon administration. No reports of failure to respond to glucagon are found in the literature. This is most probably attributable to reporting and publication bias. Further research is required.

Clinical bottom line

There is not enough evidence currently available to support the use of glucagon in tricyclic overdose.