Suppression of pentylenetetrazol-elicited seizure activity by intraosseous lorazepam in pigs.
Use of the intraosseous (i.o.) route as an alternative venous access for drug administration has increased. This study examined the efficacy of i.o. lorazepam (LZP) in suppressing pentylenetetrazol (PTZ)-induced seizure activity in pigs. Domestic swine (13-20 kg) were prepared for recordings of arterial blood pressure, EEG, and electrocortical activity. Seizure activity was induced by PTZ (100 mg/kg i.v.). Sixty seconds after onset of seizure activity, animals either received no drug (control) or LZP (1.0 mg/kg) administered i.v. or i.o. via an 18- or 13-gauge spinal needle inserted in the right proximal tibia. Both i.o. and i.v. LZP significantly suppressed the duration of seizure activity (DSA) (s/min interval) within 1 min following drug administration: DSA control, 46.2 +/- 3.6; i.v. LZP, 25.0 +/- 5.1; i.o. (18-gauge) LZP, 27.6 +/- 6.0; i.o. (13-gauge) LZP, 24.0 +/- 2.4. Seizure activity was essentially abolished at 1 min following LZP infusion. In addition, both i.v. and i.o. LZP did not have significant effects on the basal heart rate and mean arterial blood pressure. The data demonstrate that in swine (1) the i.o. route is an effective alternative venous access for LZP administration, and (2) the size of spinal needles does not affect the antiepileptic efficacy of i.o. infusion of LZP.
Jim
K F
KF
Department of Pharmacology, Medical College of Pennsylvania, Philadelphia.
Lathers
C M
CM
Farris
V L
VL
Pratt
L F
LF
Spivey
W H
WH
D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D001842:Bone and Bones; D006339:Heart Rate / Q000187:drug effects; D007262:Infusions, Intravenous; D007263:Infusions, Parenteral; D008140:Lorazepam / Q000008:administration & dosage* / Q000494:pharmacology; D010433:Pentylenetetrazole; D013226:Status Epilepticus / Q000139:chemically induced / Q000188:drug therapy*; D013997:Time Factors
D008140:Lorazepam; D010433:Pentylenetetrazole