Cardiovascular responses elicited by intragastric administration of BDL and GHB.

Gamma-hydroxybutyrate (GHB) and its metabolic precursor, 1,4-butanediol (BDL), are widely used recreational drugs. Although most commonly described as CNS depressants, GHB and BDL elicit significant sympathomimetic cardiovascular responses [increases in mean arterial pressure (MAP) and heart rate] when administered parenterally. Given that humans most commonly ingest both drugs orally, we examined the dose-response relationships for intragastrically administered GHB and BDL on MAP and heart rate in conscious rats using radiotelemetry. The intragastric administration of GHB increased MAP. BDL increased both MAP and heart rate and was approximately 10-fold more potent as a cardiovascular stimulant than GHB when administered intragastrically. Pretreatment with ethanol prevented the lethality of BDL. These data indicate that 1) both GHB and BDL produce cardiovascular responses when administered intragastrically and 2) BDL is more potent and potentially more dangerous than GHB when administered via this route.