Cross-dependence, drug

GHB treatment in mice, tolerance develops to both the hypolocomotion and cataleptic effects of the drug (Itzhak and Ali 2002). There is also preclinical evidence of cross-tolerance and cross-dependence of GHB with alcohol (Colombo et al. 1995 Fadda et al. 1989). As described in the earlier section on clinical pharmacology, GHB and its analogues have been used in humans in the treatment of alcohol withdrawal. Nicholson and Balster (2001) reviewed the evidence for cross-tolerance and cross-dependence of GHB with alcohol. 

Cross-tolerance A condition where an individual who is tolerant to the pharmacological effects of one member of a drug family also shows tolerance to other members of that family. Cross-dependence allows drug substitution during detoxification (e.g., methadone for heroin or clomethiazole for ethanol), so reducing the severity and potential danger of withdrawal symptoms. 

Cross-tolerance and cross-dependence The ability of one drug to suppress the... 

In this chapter we have attempted to emphasize the psychopharmacological mechanisms of the actions of dmgs of abuse and have used these mechanisms to describe dmg dependence as well. We have attempted to define the terms frequently used in describing drug abuse and dependence, including abuse, addiction, dependence, reinforcement, tolerance, cross-tolerance and cross-dependence, withdrawal, relapse, and rebound. 

Ross, D. D., Schneider, E. (2000). Methotrexate cross-resistance in a mitoxantrone-seiected muitidrug-resistant MGF7 breast cancer ceii iine is attributabie to enhanced energy-dependent drug efflux. Cancer Res. 60, 3514-3521. 

Cross-tolerance means that tolerance to any sedative-hypnotic drug will extend to other drugs in the same class. Cross-dependency means that use of any drug in this class, or any opioid drug will enhance the effects and abusers may turn to other drugs in either category to either supplement their drugs of choice or stand in for them if they are not readily available. 

Six cases of complications loosely related to the use of naltrexone pellet implantation during the highly controversial rapid and ultra-rapid opioid detoxification procedures have been reported (22). These included pulmonary edema, prolonged opioid withdrawal states, drug toxicity, withdrawal from cross-dependence to alcohol and benzodiazepines, aspiration pneumonia, and death. The risk of these controversial procedures and of naltrexone in this novel delivery system are high a robust scientifically validated program of research is needed to justify such treatment packages. 

Alcohol also shows cross-dependence with CNS depressant drugs. This means that taking one drug can suppress withdrawal symptoms of the other. For example, alcohol and the benzodiazepine drugs such as Valium and Librium show cross-dependence. This phenomenon has proved valuable in managing withdrawal from alcohol in individuals who arc physically dependent on it. 

T Because of the availability of drugs that show cross-dependence with alcohol, medical management of alcohol withdrawal is generally straightforward. Nevertheless, it is a serious medical condition if not treated properly or at all, alcohol withdrawal can be fatal. 

Opiate drugs show cross-dependence with... 

Cross tolerance/cross dependence occurs when tolerance or dependence develops to different drugs which are chemically or mechanistically related. For example, methadone relieves the symptoms of heroin withdrawal because patients develop cross dependence to these two drugs. 

A simple example of gel formation is provided by chitosan tripolyphosphate and chitosan polyphosphate gel beads the pH-responsive swelling abihty, drug-release characteristics, and morphology of the gel bead depend on polyelectrolyte complexation mechanism and the molecular weight. The chitosan beads gelled in pentasodium tripolyphosphate or polyphosphoric acid solution by ionotropic cross-hnking or interpolymer complexation, respectively. 

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