Increased Antiseizure Effectiveness with Tiagabine Combined with Sodium Channel Antagonists in Mice Exposed to Hyperbaric Oxygen.
Level 5 - mechanism / opinion, no new human data
Preclinical bench/animal research without human clinical data
PubMed 31148118 · doi:10.1007/s12640-019-00063-5
What was done
C57BL/6 mice were exposed to 100% oxygen at 5 atmospheres absolute (ATA) to test combinations of GABA enhancers (tiagabine, gabapentin) with sodium channel antagonists (carbamazepine, lamotrigine) for delaying hyperbaric oxygen-induced seizures. Dose-response curves were established, and tiagabine combined with carbamazepine or lamotrigine was tested across three fixed-ratio combinations (1:3, 1:1, 3:1) using isobolographic analysis to determine pharmacodynamic interactions. Bronchoalveolar lavage protein content was measured to assess protection against acute hyperoxic lung injury.
What was found
For both tiagabine combinations (with carbamazepine or lamotrigine), the maximally effective combined doses increased seizure latency over controls > 5-fold. Pharmacodynamic interactions were synergistic for the 1:1 and 3:1 fixed ratios and additive for the 1:3 ratio. Both combinations also reduced bronchoalveolar lavage protein content by ~50%.
Why it matters
Combining a GABA enhancer with a sodium channel blocker provides synergistic protection against hyperbaric oxygen-induced seizures and associated pulmonary injury in mice, suggesting dual central and peripheral benefits at lower individual doses.
Limits
The study was conducted entirely in mice, precluding direct clinical translation to humans without human trials. The abstract does not report the total sample size (n), baseline seizure latencies, exact dose values, or confidence intervals.
Cited by
- contradicts Anti-seizure drugs are ineffective at preventing central nervous system oxygen toxicity seizures unless administered at dosages high enough to induce a near-sedated coma.