Clinical Textbook of Addictive Disorders 3rd ed - R. Frances, S. Miller, A. Mack (Guilford, 2005) WW

9. Cocaine and Stimulants 207purified form of the d-isomer, often called “ice” or “glass,” is frequently sold aslarge crystals that are smoked. The freebase form of methamphetamine is a liquidat room temperature. Rocks are made by melting, cooling, and cutting themethamphetamine crystals, which is often done in an aluminum turkey roastingpan. Methamphetamine can be smoked by inhaling it from a straw placedon aluminum foil or inhaling it through a glass pipe. Methamphetamine pipesdiffer from those for crack cocaine, because the drug vaporizes at a much lowertemperature (Cook, 1991). Methamphetamine is heated by holding a lighterunder a large glass ball at the end of the pipe. A finger placed over a hole on thetop of the pipe regulates airflow.Methamphetamine elevates blood pressure, speeds heart rate, raises bodytemperature, dilates pupils, reduces food intake, and diminishes sleep. Lowdoses initially are associated with increased alertness, energy, and vigilance.Higher doses produce intoxication symptoms, including euphoria, enhancedself-esteem, and increased sexual pleasure. Even higher doses result in anxiety,irritability, tremors, paranoia, and stereotypical behavior. Tolerance (needingmore drug to achieve a given effect) or sensitization (needing less drug toachieve a given effect) may occur upon continued methamphetamine exposure.Different drug effects may have varying rates of either tolerance or sensitization(Lukas, 1997). Tolerance to methamphetamine euphoria occurs more quicklythan tolerance to its tachycardic or anorexic effects. Being more prone to seizuresand psychosis after repeated dosing with methamphetamine is an exampleof sensitization (Koob, 1997). Methamphetamine toxicity can affect manyorgan systems. Methamphetamine cardiotoxicity is related to catechol excess,and may result in myocardial infarction and/or arrhythmias. Pulmonary hypertension,rhabdomyolysis, acute renal failure, heightened immunosuppression,and idiosyncratic liver necrosis are a few of the morbidities associated withmethamphetamine use. Paranoid delusions occur in more than 80% of the casesof toxic psychosis. Acute lead poisoning is also a risk for methamphetamineusers, because lead acetate is often used as a reagent in its production. Prenatalexposure to methamphetamine is associated with pregnancy complications,prematurity, problems with reflexes, irritability, and congenital deformities.Finally, injecting methamphetamine places users (increasingly, gay male populations)at increased risk for HIV and hepatitis B and C.Methamphetamine enters the nerve terminal via the synaptic or membranetransporter, then enters the storage vesicles through vesicular transporters,forcing out neurotransmitters such as dopamine and norepinephrine. Methamphetamineis basic and disrupts the acidic interior of the synaptic vesicles,inactivating the proton pump necessary to transport dopamine back inside thevesicle. The dopamine in the cytoplasm undergoes autooxidation, which producestoxic peroxides, oxygen radicals, and hydroxylquinones, which can causedamage in such dopamine-rich areas of the brain as the ventral tegmentum andsubstantia nigra (Seiden, 1991; Seiden & Sabol, 1996). Dopamine and seroto-