Stimulants withdrawal syndromes

Dependence and withdrawal can occur with all of the stimulants. Cocaine is one of the most strongly reinforcing drugs in self-administration paradigms in animals and also has a psychological withdrawal syndrome. A typical pattern of withdrawal includes a ravenous appetite, exhaustion, and mental depression, which may last for several days after the drug is withdrawn. Because tolerance develops quickly, abusers may take large doses, compared with those used medically, for example, as anorexiants. 

There are two main treatments for the opiate withdrawal syndrome. One is replacement therapy with methadone or other X agonists that have a longer half-life than heroin or morphine, and produce mild stimulation rather than euphoria. They also produce cross-tolerance to heroin, lessening heroin s effect if patients relapse. Withdrawal is also treated with the 0C2 agonist clonidine, which inhibits LC neurons, thus counteracting autonomic effects of opiate withdrawal — such as nausea, vomiting, cramps, sweating, tachycardia and hypertension — that are due in part to loss of opiate inhibition of LC neurons. 

A variety of drugs in distinct pharmacological and chemical classes can be considered under the broad classification as stimulants. Xanthines and methylxan-thines constitute a weak class of stimulants that includes caffeine, theophylline (aminophylline),and theobromine. Caffeine is freely available in coffee, colas, and certain over-the-counter pills. A low degree of tolerance develops to some of their effects and a mild withdrawal syndrome is observed following immediate cessation of their repeated use. 

Once an amphetamine abuser stops taking the drug, withdrawal symptoms begin as the body tries to adjust to the absence of the stimulant. This results in very uncomfortable and potentially life-threatening physical symptoms, called withdrawal syndrome. According to the World Health Organization (WHO), withdrawal is experienced by 87% of amphetamine users who stop the drug. 

When a depressant drug like methaqualone is stopped abruptly, the body responds by overreacting to the substance s absence. Functions such as heart rate that were slowed by the depressant will suddenly accelerate, often erratically. Conversely, withdrawal of a stimulant drug can cause an overall sluggishness that results in depression and extreme fatigue. These changes result in very uncomfortable and potentially life-threatening physical symptoms, called withdrawal syndrome. 

In this section, caffeine is discussed only briefly and the focus is on other stimulants that produce psychiatric disorders. Caffeine can lead to a withdrawal syndrome characterized by lethargy, irritability, and headache, but withdrawal appears to occur in less than 3% of regular coffee drinkers. Moreover, the morbidity associated with caffeine overdose, which can include disturbing effects on sleep and heart rhythm, is much less than the morbidity associated with other stimulants. 

Breggin, P. (1992b). A case of fluoxetine-induced stimulant side effects with suicidal ideation associated with a possible withdrawal syndrome ( crashing ). International Journal of Risk and Safety in Medicine, 3, 325—328. 

Physical signs and symptoms of LSD intoxication include mydriasis, tachycardia, diaphoresis, palpitations, blurred vision, tremor, incoordination, dizziness, weakness, and drowsiness psychiatric signs and symptoms include perceptual intensification, depersonalization, derealization, illusions, psychosis, and synesthesia. There is no withdrawal syndrome after discontinuation. LSD and similar drugs stimulate presynaptic S-HTj and 5-HTig, as well as postsynaptic 5-HT2 receptors in the brain. 

A kind of (low-dose) dependence may also develop when alcohol is consumed daily, albeit in minor quantities. As a rule of thumb, alcohol always makes people dependent when consumed on a regular basis — no matter what the dose may be. Alcohol addiction comprises (1.) physical dependence including increased tolerance as well as the withdrawal syndrome and (2.) psychological dependence with an uncontrollable desire for permanent or intermittent alcohol consumption, reduced self-control as well as changes in behaviour, (s. tab. 28.1) Alcohol abuse includes addiction without actually being identical to it. Neither the brain s reward system (A. Herz et af, 1989) nor the addiction memory (X Boning, 1992) are stimulated by occasional alcohol consumption. Another explanation for this... 

Mazindol is a tricyclic compound with central nervous system stimulant properties similar to those of amphetamine. It releases and blocks reuptake of dopamine and noradrenaline (1), and the actions of these catecholamines, not serotonin, are responsible for its anorectic activity. With fairly high doses (6 mg/day) central nervous system effects were reported in 30% of 23 patients (2). Euphoria does not occur at therapeutic doses, but can occur at higher doses. It has a much lower addiction potential than the amphetamines and practically no cases have been reported of a physical withdrawal syndrome. 

Caffeine s pharmacologic actions are similar to those of other stimulant drugs. As such, abstinence from caffeine induces a distinct withdrawal syndrome that includes headache, drowsiness, and fatigue. 

Sennariergif systems may be important in the actions of LSD, which inhibits the firing of 5HT-containing neurones in the raphe nuclei, probably by stimulating 5HT., inhibitory autoreceptors on these cells. Tolerance to LSD and related compounds occurs, and is associated with a down-iegulation of 5HTj receptors. However, there is no withdrawal syndrome. 

Acute intoxication produces a predominantly stimulant picture (Appendix A6). Whilst there s no clear withdrawal syndrome, patients may be anxious, agitated, and conplain of pain (especially bladder-related). Unless acutely psychotic and in need of a psychiatric admission, these patients are best treated by addiction services. 

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