The effects of lamotrigine on the acquisition and expression of morphine-induced place preference in mice

Lamotrigine attenuates the motivation to self-administer ketamine and prevents cue- and prime-induced reinstatement of ketamine-seeking behavior in rats

BACKGROUND

Lamotrigine is an anticonvulsant drug used in the treatment of epilepsy and bipolar disorder. A case report has demonstrated that a ketamine addict experienced a significant reduction in craving and ketamine use after taking lamotrigine. The present study determined whether lamotrigine can reduce the motivation for ketamine and prevent the relapse to ketamine seeking behavior in rats.

METHODS

Male Sprague-Dawley rats were trained to respond for intravenous ketamine (0.5 mg/kg/infusion) self-administration or food pellets. The effects of lamotrigine on the motivation for ketamine or food were assessed using breakpoint test under a progressive ratio (PR) paradigm. Furthermore, the effects of lamotrigine on reinstatement of ketamine-seeking and food-seeking behaviors were examined after extinction.

RESULTS

Lamotrigine significantly decreased the breakpoint for ketamine and prevented cue- and ketamine priming-induced reinstatement of ketamine seeking behavior. However, lamotrigine did not affect the breakpoint for food reinforcement, cue-induced reinstatement of food-seeking behavior, or spontaneous locomotor activity.

CONCLUSIONS

Our data reveal that lamotrigine is capable of attenuating the reinforcing efficacy of ketamine and reducing ketamine craving and relapse risk, which lays the foundation for conducting clinical trials in patients with ketamine use disorder.

Anticonvulsants lamotrigine and riluzole disrupt maternal behavior in postpartum female rats

Maternal behavior is a highly motivated and well-organized social behavior. Previous studies have reported that anticonvulsants are frequently used in postpartum bipolar disorder. However, the maternal disruptive effect of the anticonvulsants has not been explored. The purpose of the present study was to examine the effect of anticonvulsants lamotrigine and riluzole on maternal behavior in postpartum female rats. On postpartum Day 3, Sprague-Dawley mother rats were given a single intraperitoneal injection of vehicle, lamotrigine (15, 25, 35 mg/kg), or riluzole (2, 4, 8 mg/kg). Maternal behavior was tested 30 min before and after injection. Animals treated with lamotrigine or riluzole had a longer pup retrieval latency, retrieved fewer pups into the nest, spent less time on nursing pups, as well as on building the disturbed nest, and animals treated with riluzole spent less time on pup licking. Whereas, the drugs in the tested doses did not shorten the total duration of behavior unrelated to maternal behavior. Overall, these data indicate that lamotrigine and riluzole disrupt major components of maternal behavior in postpartum female rats, but do not inhibit the behaviors unrelated to maternal behavior, which indicates that the maternal disruptive effect is not due to nonspecific sedative effect.

Preclinical evidence of new opioid modulators for the treatment of addiction

IMPORTANCE OF THE FIELD

Addiction to opiates is one of the most severe forms of substance dependence, and despite a variety of pharmacological approaches to treat it, relapse is observed in a high percentage of subjects. New pharmacological compounds are necessary to improve the outcome of treatments and reduce adverse side effects. Moreover, drugs that act on the opioid system can also be of benefit in the treatment of alcohol or cocaine addiction. AREA COVERED BY THIS REVIEW: Recent preclinical studies of pharmacological agents for the treatment of opiate addiction (2008 to the present date).

WHAT THE READER WILL GAIN

The reader will be informed of the latest drugs shown in animal models to modify dependence on opiates and the reinforcing effects of these drugs. In addition, reports of the latest studies to test these compounds in models of other drug addictions are reviewed.

TAKE HOME MESSAGE

The classic clinical pharmacotherapy for opiate dependence, involving mu-opioid receptor agonists or antagonists, has not yielded a high success rate in humans. In pharmacotherapy for opioid dependence, new options are emerging and different pharmacological strategies are now being tested.