Since  alcohol-dependent  persons  have  an  increased tolerance for alcohol, they react differently than moderate or heavy drinkers to the effects of alcohol. They can drink large quantities of alcohol without losing control of their actions, while the moderate or heavy drinker  cannot.  Instead  of  becoming  more  pleasant  and relaxed as do the moderate or heavy drinkers, alcoholics may  become  progressively  more  tense  and  anxious while  drinking.  They  may  accurately  perform  complex tasks  at  blood-alcohol  levels  several  times  as  great  as those  that  would  incapacitate  moderate  to  heavy drinkers. At one stage of their alcoholism, they may drink a fifth of whiskey a day without showing signs of drunkenness. Later, in the chronic stage, their tolerance decreases to the point that they may become drunk on relatively small amounts of alcohol. Alcoholics  also  differ  from  moderate  to  heavy drinkers  in  their  reactions  to  the  abrupt  removal  of alcohol.  The  normal  drinker  may  only  experience  the prosing  misery  of  the  hangover.  Alcoholics  may  suffer severe  mental  and  bodily  distress,  such  as  severe trembling,  hallucinations,  confusion,  convulsions, delirium  (the  alcohol  withdrawal  syndrome),  and delirium tremens. Both the alcohol withdrawal syndrome  and  delirium  tremens  involve  shaking, sweating, nausea, and anxiety. However, delirium tremens can cause death. The average person would have  difficulty  distinguishing  between  the  alcohol withdrawal  syndrome  and  the  delirium  tremens.  Both require  immediate  medical  attention. At present, no one knows the reason for the increased  tolerance  of  the  alcohol-dependent  person  to alcohol.  At  one  time  tolerance  levels  were  thought  to depend  on  differences  in  people’s  rates  of  alcohol metabolism.  However,  overall  rates  of  alcohol metabolism were later found not to differ much in normal  drinkers  and  alcoholics.  That  fact  indicated changes  in  tolerance  levels  must  occur  in  the  brain  rather than in the liver. DRUG INTERACTIONS WITH ALCOHOL. – Alcohol  works  on  the  same  brain  areas  as  some  other drugs.  Drinking  alcohol  within  a  short  time  before  or after t aking those drugs can multipl y the normal effects of  either  the  drug  or  the  alcohol  taken  alone.  For example,  alcohol  and  barbiturates  taken  in  combination increase the effects of each other on the central nervous system,  which  can  be  particularly  dangerous.  Alcohol taken in combination with any drug that has a depressant effect on the central nervous system is likewise dangerous. These dangerous reactions are the result of metabolism–the  way  our  bodies  chemically  process what we consume. If drugs were not metabolized within the body, their effect  would  continue  for  the  remainder  of  a  person’s life.  In  the  metabolic  process,  our  bodies  transform drugs  into  other  substances  and  eventually  eliminate them through normal bodily functions. The more rapid the rate of metabolism, the lower the impact of the drug. When drugs are forced to compete with alcohol for processing  by  the  body,  alcohol  is  metabolized  first;  the other drug then remains active in the blood for an extended time. As a result, the effect of the drug on the body  is  exaggerated  since  its  metabolism  is  slowed down  by  the  body’s  tendency  to  take  care  of  the  alcohol first. When added to the normal depressant consequence of alcohol, further depression of the nervous system, which regulates vital body functions, occurs. That serious  condition  can  result  in  death. Although anyone’s body metabolizes drugs more slowly  when  the  blood  contains  alcohol,  the  alcoholic’s [or  heavy  drinker’s]  body  metabolizes  drugs  more rapidly  during  sober  periods.  Therefore,  heavy  drinkers commonly  take  even  larger  doses  of  drugs.  The  usual quantities  taken  by  nondrinkers  or  moderate  drinkers would have little effect on the heavy drinker. The results of taking large doses of drugs and then drinking can place these persons in even greater jeopardy; the results can be fatal. LONG-TERM EFFECTS. –Drinking alcohol in moderation  apparently  does  the  body  little  permanent harm.  But  when  taken  in  large  doses  over  long  periods, alcohol can prove disastrous; it can reduce both the quality and length of life. Damage to the heart, brain, liver, and other major organs may result. Prolonged  heavy  drinking  has  long  been  known  to be  connected  with  various  types  of  muscle  diseases  and tremors.  One  essential  muscle  affected  by  alcohol  is  the heart. Some recent research suggests that alcohol may be toxic to the heart and to the lungs as well. Liver damage  especially  may  result  from  heavy  drinking. Cirrhosis of the liver occurs about eight times more often  among  alcoholics  as  among  nonalcoholics. Heavy drinkers have long been known to have lowered  resistance  to  pneumonia  and  other  infectious diseases,  usually  because  of  malnutrition.  However, recent  research  showing  well-nourished  heavy  drinkers may  also  have  lowered  resistance  indicates  that  alcohol directly  interferes  with  the  immunity  system.  People with blood-alcohol levels of 0.15 to 0.25 percent have a 3-17