Pharmacology 2010.2 15

• Antagonist at the BZD binding site on the GABA_A receptor (ligand-gated chloride channel).
• Decreases the binding of GABA.
• Blocks GABA-induced increase in Cl^- permeability and influx of Cl^- into the cell causing hyperpolarisation and decreased excitability of the neuron.

Pass Criteria:

• Specific BZD receptor antagonist at GABA receptor

• Avoid intubation or ICU admission in BZD overdose.
• Reverse BZD sedation after procedures
• Diagnostic role

Pass Criteria:

• Reverse the sedative effects of BZD

• Precipitate seizures in mixed overdoses with BZD and proconvulsants
• Precipitate seizures in pts taking BZD to control epilepsy
• Precipitate withdrawal symptoms and seizures in BDZ-dependent
• Duration of action is only 1-3hrs thus repeated administration may be necessary
• Reversal of BZD-induced respiratory depression has not been demonstrated, so respiratory and cardiovascular support may be required
• Adverse Effects:  headache, visual disturbance, increased anxiety, nausea, light-headedness

Pass Criteria:

• Precipitate fits
• Need for repeated doses