Health Effects in Animals

The adverse health effects of methamphetamine on experimental animals have been researched to some degree. Neurotoxicity, developmental toxicity, and reproductive toxicity have been suggested in animals exposed to high levels of methamphetamine and other stimulants.(7) Chronic exposure of methamphetamine given to rats has been reported to result in long-term depletions of both dopamine and serotonin in the rat brain. These effects have also been observed in monkeys. In addition, rats injected with methamphetamine have been found to develop development and behavior changes. Spatial learning impairment has also been documented in rats injected with methamphetamine. Decreases in body weight, retinal hemorrhage and mortality have also been observed. (7)

Developmental Toxicity: Developmental toxicity has been observed in mice injected with methamphetamine during gestation.(7) Both maternal and fetal body weights were reduced and increases in fetal malformations were noted. Skeletal malformations were also noted. Other anomalies such as delayed testicular decent, incisor eruption, increases in stillbirths, and postnatal mortality have also been recorded by some researchers.(7)

Long Term Exposure: It appears, however, that animals may not be as susceptible to low concentration exposures to methamphetamine as are humans.(14) The use of animal data using high exposures may not, therefore be as protective as would be human data. Human data on long-term exposure to children, especially, is not available at this time.