a. Mechanism of Action. Sedatives and hypnotics selectively depress the reticular activating system (RAS), the mechanism responsible for keeping us awake.
(1) Sedation. To sedate means to calm; therefore, sedation refers to the act of producing calm in a patient. You can also think of sedation as referring to a decreased responsiveness to a constant level of stimulation. Small doses (small amounts) of a sedative-hypnotic drug administered to a patient will produce sedation.
(2) Disinhibition. Disinhibition refers to actions a person may perform while under the effects of a drug that he would not perform if he were not taking the drug. This effect may be seen as euphoria, (feeling of well being or elation) in some patients and is a potential source of abuse of these agents. Disinhibition is presumed because of depression of a higher cortical (brain) center, which results in a resultant release of lower brain centers from constant inhibitory influence. Larger doses of a sedative-hypnotic agent will produce this effect.
(3) Relief of anxiety. This particular effect probably cannot be separated from the sedative and euphoriant effects produced by the sedative-hypnotic agents.
(4) Sleep. Sedative-hypnotic induced sleep differs in several ways from normal sleep. If a sufficiently large dose of any sedative-hypnotic agent is administered to a patient, sleep will result; however, the dose of a particular agent required to produce sleep will vary with the physiologic and psychologic state of the individual and the environmental situation in which the drug is given.
(5) Anesthesia. State III of general anesthesia (surgical anesthesia-unconsciousness and paralysis of reflexes) can be induced in humans with large doses of sedative-hypnotic agents. Short- and ultra short-acting barbiturates are the only drugs used as anesthetic agents from this class.
(6) Analgesia. Patients who have been deeply anesthetized with barbiturates are totally unresponsive to pain.
(7) Anticonvulsant activity. All the barbiturates commonly used in clinical practice are capable of inhibiting convulsions. Phenobarbital and other long-acting drugs are selectively more effective at lower therapeutic doses in the treatment of epilepsy.
(8) Cardiovascular and respiratory effects. Sedative-hypnotic agents are respiratory depressants that depress the respiratory system. Sedative-hypnotic agents do not, when administered orally, produce significant cardiovascular effects.
(9) Dependence. Both psychic and physical dependence has been reported with both the barbiturate and nonbarbiturate sedative-hypnotic agents. Dependence usually occurs when sedative-hypnotics are given over a long period in large doses. Therefore, continued administration of these agents is usually necessary to prevent a withdrawal state in the patient.
Sedative-hypnotic agents are used to treat a variety of conditions. These include:
a. Relief of Anxiety. Sedative-hypnotics are effectively used to temporarily relieve anxiety associated with threatening or fearful situations (for example, anxiety that typically occurs before a surgical procedure).
b. Treatment of Depression. Depression is the most common manifestation of anxiety. Treatment of depression with sedative-hypnotic agents may be effective. It should be noted that major (psychotic) depressions might be intensified with sedative-hypnotics.
c. Induction of Sleep (Hypnosis). Short-acting sedative-hypnotics are generally used because of less hangover or persistent effects. When used to produce sleep, sedative-hypnotics should not be administered continuously and should only be part of an overall plan of management and counseling.
d. Anticonvulsant Therapy. Some sedative-hypnotics (for example, phenobarbital) have been successfully used in the treatment of various types of convulsive disorders.
e. Skeletal Muscle Relaxation. Some sedative-hypnotics have been used to produce muscle relaxation in patients. However, the effectiveness of sedative-hypnotics for this use may be related more to their sedative properties than to their ability to produce true muscle relaxation.
f. Anesthesia. The ultra short-acting barbiturates (for example, thiopental) are used for surgical procedures of short duration.
Was this article helpful?
Tips And Tricks For Relieving Anxiety... Fast Everyone feels anxious sometimes. Whether work is getting to us or we're simply having hard time managing all that we have to do, we can feel overwhelmed and worried that we might not be able to manage it all. When these feelings hit, we don't have to suffer. By taking some simple steps, you can begin to create a calmer attitude, one that not only helps you feel better, but one that allows you the chance to make better decisions about what you need to do next.