Effects of Chronic Use

Information on the mutagenic potential of SNA Is almost completely lacking. A single abstract reported the cytogenetic effect of chronic use of the drug over 2-3 yr by one male and four females 18-26 yr old. The most frequent route of administration was Inhalation of smoke from a blend of SNA and marijuana. No chromosomal abnormalities were found In this limited investigation. 8... 

Acute Effects at High Doses Effects of Chronic Use... 

The effects of a ketamine high usually last an hour, but they can last for 4 to 6 hours, and 24 to 48 hours are generally required before the user will feel completely normal again. Effects of chronic use of ketamine may take from several months to 2 years to disappear completely. Low doses (25 to 100 mg) produce psychedelic effects quickly. Large doses can produce vomiting and convulsions and may lead to hypoxia of the brain and muscles 1 g can cause death. Flashbacks may even occur 1 year after use. Long-term effects include tolerance and possible physical and/or psychological dependence. 

Cantopher T, Olivieri S, Cleave N, et al Chronic benzodiazepine dependence a comparative smdy of abrupt withdrawal under propranolol cover versus gradual withdrawal. Br J Psychiatry 156 406-411, 1990 Caplan RD, Andrews FM, Conway TL, et al Social effects of diazepam use a longitudinal field study. Soc Sci Med 21 887—898, 1985 Charney DA, Paraherakis AM, Gill KJ The treatment of sedative-hypnotic dependence evaluating clinical predictors of outcome. J Clin Psychiatry 61 190—195, 2000... 

Rapid dermal absorption of trichloroethylene is evident from a study in which peak blood and exhaled air concentrations occurred within 5 minutes after a human subject immersed one hand in a solution of unspecified trichloroethylene concentration for 30 minutes (Sato and Nakajima 1978). Studies on dermal absorption of trichloroethylene in humans, as well as animals, are complicated by the fact that exposure in these studies is usually by direct contact of the skin with the undiluted chemical. Trichloroethylene is a lipophilic solvent that defats the skin and disrupts the stratum comeum, thereby enhancing its own absorption. Thus, the rate of absorption probably increases in a nonlinear fashion with greater epidermal disruption. Although the extent of absorption through the skin may be relatively modest with normal industrial use (Sato and Nakajima 1978 Stewart and Dodd 1964), there is insufficient information to evaluate the effects of chronic, low-level exposure in hiunans, especially when multiple routes may be involved. 

Much less attention has been paid to chronic PCP use per se, i.e., the substance use disorder itself. Such issues as the effects of chronic PCP use, and the diagnosis, clinical characterization, and treatment of chronic PCP abusers are rarely discussed in the published literature, even in detailed review articles (Davis 1982 Pearlson 1981 Pradhan 1984). This paper reviews the literature on inpatient and outpatient treatment of PCP abuse, outlines our own experience with PCP users and abusers in one large, public, urban hospital, and makes suggestions for future research based on this information and animal research findings (Balster, this volume). 

Develop a plan to assess the effectiveness of laxative use in cases of chronic constipation. 

Short-term use of corticosteroids is not associated with most of the adverse effects of chronic steroid use. The most common adverse effects encountered are gastrointestinal upset, insomnia, and mood swings.28... 

Moderate levels of chronic use of caffeine and other arousal agents tend to reduce the effects of acute exposure. However, higher chronic levels can exacerbate the impact of acute exposure. 

Cosgrove, K., Ellis, S., Al-Tikriti, M. et al. Assessment of the effects of chronic nicotine on P2-nicotinic acetylcholine receptors in nonhuman primate using [I-123]5-IA-85830 and SPECT. Paper presented at the 66th Annual Scientific Meeting of the College on Problems of Drug Dependence, 2004, San Juan, Puerto Rico. 

Acute physiological responses to opiate administration occur rapidly and include constricted pupils, decreased pulse rate, reduced body temperature, slowed respiration rate and impaired reflexes. In addition, there is a marked slowing of the digestive system through an altering of the tonus and motility of the stomach and intestines, allowing for greater water absorption. This last effect is not subject to tolerance, and constipation is a common side effect even for chronic users. Indeed, some report that this is the worst side effect of opiate use. 

Similar to LSD and other monoamine hallucinogens, mescaline suppresses locomotor and exploratory behavior in novel environments (Wing et al. 1990). Also similar to LSD, tolerance develops to the behavioral effects of chronic doses of mescaline (Murray et al. 1977). Mescaline increases aggression in rat models (Sbordone et al. 1978) however, this is an elicited aggression (by electric shock) and does not necessarily generalize to human behavior. Increased aggression is not characteristic of humans using mescaline. 

Wert RC, Raulin ML. (1986). The chronic cerebral effects of cannabis use I. Methodological issues and neurological findings. Int J Addict. 21(6) 605-28. 

Further data on the effects of chronic inhalation exposure to 1,4-dichlorobenzene would be useful, especially because chronic exposures to 1,4-dichlorobenzene in the air, in the home, and the workplace are the main sources of human exposure to this chemical. Any further testing of the effects of chronic exposure to 1,4-dichlorobenzene via the oral route should probably be done at lower levels of 1,4-dichlorobenzene than those that have already been used in the NTP (1987) bioassay, and should focus on dose-response relationships involving the hepatic, renal, hematopoietic, central nervous system, and metabolic pathways. Data on the effects of chronic dermal exposure to 1,4-dichlorobenzene may be useful if dermal absorption and systemic distribution of 1,4-dichlorobenzene can be demonstrated from toxicokinetic studies, since chronic dermal exposure to 1,4-dichlorobenzene occurs as a result of bathing and showering in drinking water that contains low levels of this chemical in many U.S. communities. 

The terms acute and chronic are also used to characterize the time delay between exposure and the onset of symptoms. Acute effects are those noticed directly following exposure and are usually easily related to the agent. The chronic or long-term effects of an agent may occur years later and are often very difficult to attribute to a particular cause. The acute effects of alcohol consumption or exposure to the solvent in glue are obvious in the drunkenness produced. The effects of chronic exposure to these compounds, as seen by an alcoholic, are very different specifically, cirrhosis of the liver. The chronic effect of childhood lead exposure... 

In general, the effects of an acute ozone exposure on plant metabolism will be illustrated using data from soybean, cv. Dare. The soybeans were exposed to ozone for two hr when the first trifoliate leaf was 50 to 60% expanded and analyzed for various metabolites and enzyme activities at 0, 24, 48 and 72 hr following termination of exposure. To illustrate the effects of chronic ozone exposures, data from Ponderosa pine seedlings will be used. Ponderosa pine were grown from seed under field conditions and exposed to 200 yg/m of ozone 6 hr per day throughout the growing season. Harvests were made at monthly intervals after the initiation of exposure. 

Hardman, ]. T., M. L. Beck and C. E. Owensby. Range forb lectins. Transfusion 1983 23(6) 519-522. Mendelson, ]. H., ]. Ellingboe, ]. C. Kuehnle and N. K. Mello. Effects of chronic marihuana use on integrated plasma testosterone and luteinizing hormone levels. J Pharmacol Exp Ther 1978 207 611-617. 

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