is  not  used  as  a  food.  Drugs  are  used  on  or  ad- ministered to humans or animals as an aid in the diagnosis, treatment, or prevention of disease or other  abnormal  condition,  for  the  relief  of  pain or   suffering,    or  to  control  or  improve  any physiologic  or  pathologic  condition.  A  drug  may be  classified  in  various  categories,  depending  upon different  criteria.  Examples  are  general,  chemical, and  therapeutic. l l l General—Drugs are grouped according to their  source,  whether  animal,  vegetable,  or mineral  in  origin. Chemical—Medications   are   grouped   by their  chemical  characteristics.  Examples are  acids,  bases,  or  salts. Therapeutic    (Pharmacological)—Drugs are classified according to their action on the body. A drug may have more than one action. Drugs chemical, NOMENCLATURE normally  have  three  different generic,  and  trade  (brand). names: l l l Chemical  name—Tells  the  chemical  and molecular  structure.  An  example  is  2,  4, 7-triamino-6-phenylpteridine. — — Generic   name—Often   derived   from   the chemical name, it is the common name of the  drug.  An  example  is  Triamterene.  Note the  underlining  of  the  chemical  name above. Trade name—This is the name given by the manufacturer and is a proprietary name, it is also called the brand name. An exam- ple  is  Dyrenium,  a  brand  of  triamterene made  by  Smith,  Kline,  and  French. DRUG  GROUPS The drugs discussed in this chapter are those in common use, or are in the Medical Stock List, and  are  grouped  according  to  pharmacological classes. Only a brief summary is possible here and the corpsman who desires a more complete study of each drug should refer to the USP-NF or other reference  books  indicated  at  the  end  of  this chapter. ANTACIDS Antacids   are   drugs   used   to   counteract hyperacidity  in  the  stomach.  Normally,  there  is a certain degree of acidity in the stomach. An ex- cess  of  acid  can  irritate  the  mucous  membranes and  is  commonly  known  as  indigestion,  heart- burn,  or  dyspepsia.  In  some  disease  states,  the gastrointestinal   tract   may   become   excessively acidic (very low pH), causing diarrhea or leading to peptic ulcer formation. Antacids may interfere with the body’s ability to utilize many drugs. For this reason, most oral drugs should not be taken within  2  hours  of  taking  an  antacid.  NOTE:  As a hospital corpsman, it is important to be aware of the significance of the sodium content of most antacids,  particularly  in  the  cardiac  patient  or  pa- tients  on  a  low  sodium  diet. Magnesium Hydroxide (Milk of Magnesia USP) ACTION   AND   USE.—   Milk   of   magnesia reacts  with  gastric  acid  to  form  magnesium chloride and has a prolonged duration of action. It is preferably taken on an empty stomach with lots  of  fluid.  Do  not  use  when  abdominal  pain, nausea, or vomiting is present. Shake well. Pro- longed use may result in kidney stones. It also has a  laxative  effect. USUAL DOSE.— 5 to 10 ml four to six times a day, up to a maximum of is  15  to  30  ml. Aluminum Hydroxide Gel 60 ml. Laxative dose (Ampoojel) ACTION  AND  USE.—  This drug is used in the  management  of  peptic  ulcer,  gastritis,  and gastric hyperacidity. The major advantage of this drug is that no systemic alkalosis is produced. It may  cause  constipation. USUAL DOSE.— 15 ml four to six times daily between  meals  and  at  bedtime. Alumina and Magnesia Oral Suspension (Maalox) ACTION  AND  USE.—  Alumina  and  mag- nesia oral suspension coats the stomach lining and neutralizes gastric acid. It is less constipating than aluminum  hydroxide  alone. 7-4