Interaction of clonidine and morphine with lidocaine in mice and rats

Moshe Garty, Zvi Ben-Zvi, Aryeh Hurwitz

Research output: Contribution to journalArticlepeer-review

8 Scopus citations


Morphine and clinidine both elevated plasma levels of lidocaine to the same extent in mice while slowing lidocaine metabolism to deethylated products. The effects of clonidine on lidocaine disposition were reversed by yohimbine. Mice given morphine, 20 mg/kg sc, or clonidine, 0.2 mg/kg sc, had similar, 30-50%, elevation of plasma lidocaine levels at 15 min after lidocaine, 15 mg/kg iv, when compared to saline-treated animals. Despite similarity of effect on plasma lidocaine, mice treated with morphine were much more susceptible to lethal effects of lidocaine than were mice given clonidine. Ativ doses of 22 mg/kg or higher, lidocaine caused death in nearly all morphine-treated mice, while even 32 mg/kg lidocaine caused only 11% mortality after saline or clonidine. Clonidine, 0.5 mg/kg sc, and morphine, 20 mg/kg sc, both raised plasma lidocaine levels in rats, but only morphine depressed respiration, causing hypoxia, hypercapnia, and acidosis and increasing lidocaine lethality. These data suggest that potentiation of lidocaine toxicity by morphine is due primarily to changes in blood gases rather than to elevation in lidocaine levels.

Original languageEnglish
Pages (from-to)255-260
Number of pages6
JournalToxicology and Applied Pharmacology
Issue number2
StatePublished - Nov 1989
Externally publishedYes


Dive into the research topics of 'Interaction of clonidine and morphine with lidocaine in mice and rats'. Together they form a unique fingerprint.

Cite this