Intravenous self-administration of heroin, cocaine, and the combination in Balb/c mice

Eur J Pharmacol. 1997 May 20;326(2-3):119-25. doi: 10.1016/s0014-2999(97)85405-2.


Polydrug abuse, including the abuse of cocaine + heroin combinations (or 'speedballs') is an increasingly significant problem. The use of genetically defined populations of mice has the potential to add considerably to the study of polydrug abuse. Balb/cByJ (Balb/c) mice have been shown to self-administer opiates, but not cocaine, therefore these mice were chosen for the initial characterization of intravenous self-administration of cocaine + heroin combinations. Mice were implanted with chronic indwelling jugular catheters and given the opportunity to self-administer heroin, cocaine or heroin + cocaine combinations. Heroin was self-administered, while, under the same conditions, none of the mice tested acquired cocaine self-administration. However, heroin + cocaine combinations were self-administered in naive mice as well as in mice that had failed to self-administer cocaine alone. The heroin + cocaine combination dose-effect curve resembled the heroin dose-effect curve. It is hypothesized that heroin may interact with effects of cocaine that function to limit self-administration in Balb/c mice, facilitating the acquisition and maintenance of self-administration of cocaine + heroin combinations.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Catheterization, Central Venous
  • Cocaine / administration & dosage*
  • Dose-Response Relationship, Drug
  • Drug Combinations
  • Heroin / administration & dosage*
  • Injections, Intravenous
  • Male
  • Mice
  • Mice, Inbred BALB C
  • Narcotics / administration & dosage*
  • Self Administration
  • Substance Abuse, Intravenous*


  • Drug Combinations
  • Narcotics
  • Heroin
  • Cocaine