Impact of an oral theophylline loading dose pre-electroconvulsive therapy: a retrospective study in patients with missed or inadequate seizures.

OBJECTIVE

The aim of this study was to determine the safety and impact of an oral theophylline loading dose calculated to achieve a 10- to 15-mg/L plasma concentration when administered 1.5 hours before electroconvulsive therapy (ECT).

METHODS

We conducted a retrospective study using inpatient hospital records between January 2007 and June 2012 at the Dr. Georges L. Dumont University Hospital Centre. Patients receiving a series of ECTs with a calculated theophylline loading dose were selected. Variables collected include ECT parameters for each ECT, medications received, and treatment-related side effects.

RESULTS

We identified 35 patients and analyzed 14 who had no treatment modifications except for the addition of theophylline. The mean predicted theophylline plasma concentration was 12.99 (SD, 1.09) mg/L with dosages ranging from 260 to 600 mg. Eight patients (89%) with abortive seizures and 4 (80%) with missed seizures achieved a seizure duration of greater than 15 seconds with theophylline. Seizure duration increased by 165.6% (+21.3 seconds; P = 0.048) with theophylline, and all patients (N = 5) with a maximum sustained coherence of less than 92% achieved an increase after theophylline; however, the overall increase (+8.8%, P = 0.087) was not significant. No theophylline-related adverse events were documented in 128 ECTs with theophylline, and no seizure exceeded 120 seconds.

CONCLUSIONS

A calculated theophylline loading dose before ECT is well tolerated and effective in prolonging seizure duration and aiding with seizure generation in patients who do not seize readily. Its positive impact in patients with lower maximum sustained coherence, in addition to the potential existence of a dose-response relationship, should be further investigated.