CENTRAL NERVOUS SYSTEM STIMU- LANTS.—Certain drugs stimulate the activity of various portions of the central nervous system (CNS). The Manual of the Medical Department (MANMED) is explicit as to the usage of these drugs in the Navy. Primary indications for this class of drugs are narcolepsy, hyperkinesis, and attention deficit disorders in children. Central nervous system stimulants are generally contraindicated in patients with hypertension, arteriosclerosis, symptomatic cardiovascular disorders, agitated states, glaucoma, or history of drug abuse. (See appendix IV, page 12.) CENTRAL NERVOUS SYSTEM DEPRES- SANTS.—Central nervous system (CNS) depressants range in depressive action from mild sedation to deep coma, differing mainly in rapidity, degree, and duration of action. Any of these CNS depressants may, in sufficient doses, cause respiratory depression. Alcohol use while taking CNS depressants should be avoided. Many of the central nervous system depressants are controlled medications. Refer to the MANMED for control, custody, and accountability guidelines for controlled substances. Barbiturates comprise a widely used group of CNS depressants. They are used mainly as sedative-hypnotics, anticonvulsants, anesthetics for short anesthesia, and may be used in combination with analgesics to enhance their analgesic effect. NOTE: Barbiturates may be habit forming. See appendix IV, page 12, for examples of central nervous system depressants. OPIUM AND OPIUM ALKALOIDS.—The activity of opium is primarily due to its morphine content. The major medical use of opium has been for its antiperistaltic activity, particularly in diarrhea. Opium alkaloids, e.g., morphine and codeine, have replaced opium in medical use. Members of this drug group are used as analgesics, cough sedatives, and for certain types of diarrhea. (See appendix IV, pages 12 and 13.) NOTE: Warn patients taking opium or opium alkaloids that drowsiness, dizziness, and blurring of vision may occur. For this reason, they should not drive or perform other tasks that require alertness. Also, caution patients against consuming alcohol and other CNS depressants. Patients should notify their physician immediately if shortness of breath or difficulty in breathing occurs. P S Y C H O T H E R A P E U T I C A G E N T S . — Tranquilizers and mood modifiers are the two primary groups of psychotherapeutic agents. Psychothera- peutic agents are classified as major tranquilizers, minor tranquilizers, and mood modifiers. The mood modifiers have replaced amphetamines as treatment of choice for depressive states. (See appendix IV, pages 13 and 14.) SKELETAL MUSCLE RELAXANTS.— Skeletal muscle relaxants are used in connection with the treatment of muscle spasm due to various conditions. They may also be used to produce muscular relaxation during surgical anesthesia. Skeletal muscle relaxants may cause drowsiness and impair performance of tasks that require alertness. (See appendix IV, page 14.) CARDIOVASCULAR AGENTS.—Cardio- vascular agents affect the action of the circulatory system. Most of these agents are highly specialized. (See appendix IV, pages 14 and 15.) VASOCONSTRICTORS.—Vasoconstrictors produce constriction of the blood vessels with consequent rise in blood pressure. (See appendix IV, page 15.) ANTICOAGULANTS.—Anticoagulants delay or prevent blood coagulation. Before an anticoagulant agent is prescribed and its dosage determined, laboratory testing of the patient’s blood-clotting capabilities should be performed. Examples of commonly used anticoagulants are listed in appendix IV, page 15. VITAMINS.—Vitamins are unrelated organic substances that occur in many foods and are necessary for the normal metabolic functioning of the body. Vitamins may be water-soluble or fat-soluble. The majority of vitamins are water-soluble. Water-soluble vitamins are excreted in the urine and are not stored in the body in appreciable quantities. The fat-soluble vitamins (A, D, E, and K) are soluble in fat solvents and are absorbed along with dietary fats. Fat-soluble vitamins are not normally excreted in the urine and tend to be stored in the body in moderate amounts. See appendix IV, page 16, for a listing of several of the major vitamins and their respective properties. GENERAL AND LOCAL ANESTHETICS.— Generally speaking, anesthesia means “without feeling.” Consequently, we apply the word to drugs that produce insensibility to pain. The field of anesthesia is a highly specialized one. 6-7