Vocabulary. emergency – критичний стан, надзвичайний випадок; критическое положение, чрезвычайное обстоятельство

emergency – критичний стан, надзвичайний випадок; критическое положение, чрезвычайное обстоятельство

to mimic – імітувати; имитировать

to influence – впливати; влиять, воздействовать

oppose – протиставляти; противопоставлять

simi­lar – подібний, схожий; подобный, сходный

involuntary – мимовільний, невимушеений; непроизвольный

flow – потік; поток

retention – затримка; задержка

constrict – скорочувати; сокращать

bladder – міхур; пузырь

dilate – розширяти; расширять

excess – надлишок; избыток, излишек

to slow down – уповільнювати; замедлять

Answer the questions:

1. What are two major types of drugs acting on the nervous system?

2. What drugs are called adrenergic agents?

3. What drugs mimic the action of parasympathetic nerves?

4. How do Parasympatholytic and Sympatholytic agents act?

5. To what group of drugs does atropine belong?

TEXT 2

NEUROPHARMACOLOGIC DRUGS

(continued)

Central Nervous System Drugs. The drugs which affect the central nervous system are of two main types: those which stimulate the nerves in the brain and spinal cord, stimulants, and those which depress the nerves in the brain and spinal cord, depressants.

Stimulants. Central nervous system stimulants are used to speed up vital processes in cases of shock and collapse, and also to oppose the de­pressant effect of other drugs. Stimulants produce a temporary feeling of euphoria (well-being) and help to relieve lethargy. Examples of drug stimulants are caffeine and amphetamine. Side effects of caffeine, which is obtained from tea leaves and coffee beans, are tachycar­dia and irritability, as well as insomnia. Amphetamines are much more powerful than caffeine and can produce restlessness, insomnia, and ner­vousness, as well as hypertension (high blood pressure) and gastrointes­tinal disorders when given in high doses. Used in excessive doses, these drugs can produce convulsions.

Depressants. There are several types of central nervous system depressants. These include analgesics, hypnotics, sedatives and barbitura­tes, tranquilizers, anticonvulsants, alcohol, and anesthetics.

Analgesics are agents which act to relieve pain. Examples of analge­sics are acetylsalicylic acid (aspirin), acetaminophen and dextropropoxyphene. Aspirin and Tylenol are antipyretics (agents against fever) as well as analgesics. Dextropropoxyphene is used to lessen any type of mild pain, especially in recurrent or chronic disease.

Acetylsalicylic acid, acetaminophen, and dextropropoxyphene are examples of non-narcotic analgesics. Examples of narcotic analgesics are opium, morphine, heroin, codeine, and meperidine. Narcotics are drugs which, in moderate doses, can suppress the central nervous sys­tem and relieve pain, but in excessive doses produce unconsciousness, stupor, coma, and possibly death. Most of the narcotic analgesics are addictive and habit-forming.

Hypnotic drugs are those which depress the central nervous system and produce sleep.

Sedatives are used to quiet and relax the patient with­out necessarily producing sleep. Some drugs act as sedatives in small doses and as hypnotics in larger doses.

Barbiturates, such as phenobarbital, secobarbital, and pentobarbital, are the best known sedatives and hypnotics. Chloral hydrate is an example of another type of sedative. Depending on the dose and how it is administered, the response to a bar­biturate may range from mild sedation to hypnosis and finally to general anesthesia.

Tranquilizers are drugs which alter behavior, allowing for control of nervous symptoms such as anxiety, depression, fear, or anger. Minor tranquilizers, such as chlordiazepoxide and diazepam, are used primarily for control of less severe nervous states, while the ma­jor tranquilizers, such as phenothiazines and tricyclic antidepressants, such as amitriptyline, are used to con­trol severe disturbances of behavior or psychoses (loss of contact with reality).

Anticonvulsant agents are used to treat epilepsy, a central nervous system disorder caused by abnormal electrical discharges within the brain which result in abnormal muscular movements, loss of cons­ciousness, and other symptoms. Ideally, anticonvulsant drugs should de­press the part of the brain which controls motor, or movement, activity and not the sensory and cognitive (thinking) parts of the brain. An exam­ple of an effective anticonvulsant drug is diphenylhydantoin.

Barbiturates like phenobarbital are also used as anticonvulsant drugs.

Alcohol is another central nervous system depressant. It affects the cerebral cortex of the brain in several ways. One way is to block the pro­cesses which control or inhibit behavior. This effect accounts for the talka­tiveness and lack of inhibition which accompany consumption of even small amounts of alcohol in some people. Alcohol is also used as a dilator of blood vessels in vascular disease, as an antiseptic, and as a hypnotic.

Anesthetics are drugs which produce loss of sensation, and particular­ly loss of the appreciation of pain. General anesthetics produce loss of sensation throughout the entire body by depressing the central nervous system, producing sleep, unconsciousness, and muscle relaxation. Examples of general anesthetics are diethyl ether, nitrous oxide, thiopental. Local anesthetics relieve or prevent pain in a particular area of the body. The names of most of the local anesthetics have the suf­fix -caine. Examples are cocaine, procaine (Novocain), lidocaine, and tetracaine