Caffeine dependence potential

The various stimulants have no obvious chemical relationships and do not share primary neurochemical effects, despite their similar behavioral effects. Cocaines chemical strucmre does not resemble that of caffeine, nicotine, or amphetamine. Cocaine binds to the dopamine reuptake transporter in the central nervous system, effectively inhibiting dopamine reuptake. It has similar effects on the transporters that mediate norepinephrine and serotonin reuptake. As discussed later in this chapter in the section on neurochemical actions mediating stimulant reward, dopamine is very important in the reward system of the brain the increase of dopamine associated with use of cocaine probably accounts for the high dependence potential of the drug. 

Many studies reviewed by Tanda and Goldberg (2000) have found evidence for interactions of nicotine with caffeine and drug discrimination studies have further expanded these investigations (Sect. 6.6). The bidirectional, dose-dependent nature of caffeine effects on nicotine discrimination invites comparisons with parallel studies of nicotine self-adminisfration. However, whereas very large chronic doses of caffeine that were much above those obtained by consumers of caffeinated beverages potentiated nicotine self-administration (Shoaib et al. 1999), there is a... 

Caffeine has been proposed as a model of drug abuse despite the facts that its sale is largely unrestricted and that heavy consumption of caffeine-containing beverages is not considered to be drug abuse. A recent exhaustive review of caffeine dependence focused on the potential for abuse of caffeine and the nature of tolerance and withdrawal and presents a symposium of current knowledge as to the site(s) and mechanism of action of caffeine. A second comprehensive review of human and animal data on coffee and caffeine consumption and caffeine dependence, withdrawal, and reinforcement also has been published. " The information below represents a broad overview of these topics, and the reader interested in more detail is urged to consult these two reviews. " ... 

Chronic use of large amounts of caffeine has been associated with an increased risk of cardiovascular disease. However, this finding is debated because statistically adjusting for other risk factors shows a minimized added risk for caffeine (Grobbee et al. 1990). Nonetheless, a lipid fraction of boiled coffee dose-dependently elevates cholesterol and low density lipoproteins, which is prevented by the filtered preparation of coffee (Pirich et al. 1993). Another potential influence on cardiovascular disease is an elevation of homocysteine levels, which also occurs in drinkers of filtered coffee (Nyg rd et al. 1997). Genotoxicity... 

Adenosine is a nucleoside that occurs naturally throughout the body. Its half-life in the blood is less than 10 seconds. Its mechanism of action involves activation of an inward rectifier K+ current and inhibition of calcium current. The results of these actions are marked hyperpolarization and suppression of calcium-dependent action potentials. When given as a bolus dose, adenosine directly inhibits atrioventricular nodal conduction and increases the atrioventricular nodal refractory period but has lesser effects on the sinoatrial node. Adenosine is currently the drug of choice for prompt conversion of paroxysmal supraventricular tachycardia to sinus rhythm because of its high efficacy (90-95%) and very short duration of action. It is usually given in a bolus dose of 6 mg followed, if necessary, by a dose of 12 mg. An uncommon variant of ventricular tachycardia is adenosine-sensitive. The drug is less effective in the presence of adenosine receptor blockers such as theophylline or caffeine, and its effects are potentiated by adenosine uptake inhibitors such as dipyridamole. 

Polybrominated Biphenyls. A recent study has used caffeine as a potential tool to characterize exposure and/or effect of PBBs (Lambert et al. 1990). In this test, caffeine is used as a metabolic probe of cytochrome P-450 isozymes activity from the CYPIA family, which in animals is significantly induced by PBBs (Safe 1984). Tire caffeine breath test (CBT) is primarily useful for detecting induction of CYP1A2 activity in human liver, and for that reason, it also has been used as a marker for exposure to PCBs, CDDs, and CDFs (Lambert et al. 1992). A volunteer population of 50 Michigan subjects with previously high serum PBB levels and 50 with undetectable or low serum levels was compared to a control population not exposed to PBBs (Lambert et al. 1992). Two tests were conducted, the CYP1A2-dependent caffeine... 

The factors are diverse, ranging from caffeine consumption during pregnancy to maternal age at conception. The environmental agents with potential adverse impacts on fetal development for which there is the strongest evidence are all culture-dependent tobacco smoke, alcohol (ethanol), cocaine, and combustion-engine carbon monoxide.4 In this book I focus only on factors for which there is evidence known to me. What the factors all have in common is that all have heavy cultural... 

Both prophylactic naps and caffeine helped to maintain alertness and performance. In the real world, however, naps and caffeine have separate advantages and disadvantages that help dictate their use. Prophylactic naps clearly had the advantage of a long-lasting effect and could probably be used with some frequency without the development of tolerance, dependency, withdrawal or side effects. On the other hand, naps must be planned and may consume a substantial amount of time. Caffeine clearly can be used when time is insufficient for a nap, but carries the potential risks of most pharmacological interventions. One strategy that may be superior to either the use of caffeine or prophylactic naps may be the use of both. This was tested in the second study. 

Lobeline has been reported as a useful agent to treat dependency on drugs such as cocaine, amphetamine, caffeine, pheny Icy dine, opiates, barbiturates, benzodiazepines, cannabinoids, hallucinogens, alcohol, and, especially, nicotine. Dwoskin [55] described a novel mechanism of action and potential use for lobeline as a treatment for psychostimulant abuse. 

Several species, including dogs, foxes, badgers, horses, and the New Zealand kea (an alpine parrot), have a very limited capacity to metabolize theobromine 2 which tends to accumulate and become toxic with potentially fatal consequences [58, 59]. Depending upon the size of the dog, as little as 100-200 mg of theobromine, which can be the content of 100 g of milk chocolate or 10 g of dark chocolate [60], can be fatal. Caffeine consumption by horses leads to theophylline accumulation and hyperactivity [61]. 

Stoilov, L. M., Mullenders, L. H. F., and Natarajan, A. T, 1994, Caffeine potentiates or protects against radiation-induced DNA and chromosomal damage in human lymphocytes depending on temperature and concentration, Mutat. Res. 311 169-174. 

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