Tranquilizer

Tranquilizer, common name applied to a class of drugs used to treat anxiety and insomnia. Originally the term comprised two groups: the major tranquilizers—the phenothiazines, such as chlorpromazine (Thorazine)—useful in the treatment of acutely ill mental patients (see Mental Illness); and the minor tranquilizers—the benzodiazepines, such as diazepam (Valium).

The minor tranquilizers are safe when taken alone, but taking substantial amounts of these substances at the same time as alcohol can lead to coma or even death. Long-term administration of larger than usual doses of the benzodiazepines can cause physical dependence, with typical withdrawal symptoms ranging from nightmares to convulsions when the drug intake is stopped.

Schizophrenia

Schizophrenia, severe mental illness characterized by a variety of symptoms, including loss of contact with reality, bizarre behavior, disorganized thinking and speech, decreased emotional expressiveness, and social withdrawal. Usually only some of these symptoms occur in any one person. The term schizophrenia comes from Greek words meaning “split mind.” However, contrary to common belief, schizophrenia does not refer to a person with a split personality or multiple personality. (For a description of a mental illness in which a person has multiple personalities, see Dissociative Identity Disorder.) To observers, schizophrenia may seem like madness or insanity.

SYMPTOMS:

A variety of symptoms characterize schizophrenia. The most prominent include symptoms of psychosis—such as delusions and hallucinations—as well as bizarre behavior, strange movements, and disorganized thinking and speech. Many people with schizophrenia do not recognize that their mental functioning is disturbed.

• Delusions -> Delusions are false beliefs that appear obviously untrue to other people. For example, a person with schizophrenia may believe that he is the king of England when he is not.
• Hallucinations -> People with schizophrenia may also experience hallucinations (false sensory perceptions). People with hallucinations see, hear, smell, feel, or taste things that are not really there. Auditory hallucinations, such as hearing voices when no one else is around, are especially common in schizophrenia.
• Bizarre Behavior -> People with schizophrenia often behave bizarrely. They may talk to themselves, walk backward, laugh suddenly without explanation, make funny faces, or masturbate in public.
• Disorganized Thinking and Speech -> People with schizophrenia sometimes talk in incoherent or nonsensical ways, which suggests confused or disorganized thinking. In conversation they may jump from topic to topic or string together loosely associated phrases. They may combine words and phrases in meaningless ways or make up new words. In addition, they may show poverty of speech, in which they talk less and more slowly than other people, fail to answer questions or reply only briefly, or suddenly stop talking in the middle of speech.
• Social Withdrawal -> Another common characteristic of schizophrenia is social withdrawal. People with schizophrenia may avoid others or act as though others do not exist. They often show decreased emotional expressiveness. For example, they may talk in a low, monotonous voice, avoid eye contact with others, and display a blank facial expression.
• Other symptoms of schizophrenia include difficulties with memory, attention span, abstract thinking, and planning ahead. People with schizophrenia commonly have problems with anxiety, depression, and suicidal thoughts.

CAUSES:

Schizophrenia appears to result not from a single cause, but from a variety of factors. Most scientists believe that schizophrenia is a biological disease caused by genetic factors, an imbalance of chemicals in the brain, structural brain abnormalities, or abnormalities in the prenatal environment. In addition, stressful life events may contribute to the development of schizophrenia in those who are predisposed to the illness.

Hallucination

Hallucination is a false perception in any of the five sensory modalities when no external stimulus exists, as when a nonexistent object is seen. Hallucinations may occur in the twilight state between sleeping and awakening, or in delirium, delirium tremens, or exhaustion; they also may be induced under hypnosis. The visual sense is most often affected. Persistent hallucinations are characteristic of schizophrenia. In one type of schizophrenia, victims believe that they hear accusing or commanding voices, to which they may react in panic, with abject obedience, or with attempts at self-protection or even suicide. Hallucination is distinguished from illusion, a false perception of an actual stimulus, and is common following self-administration of certain drugs such as mescaline, marijuana, and lysergic acid diethylamide (LSD). Both illusions and hallucinations can be drug induced. See Drug Dependence; Psychoactive Drugs.

HIV Treatment

No treatment is available that cures AIDS, but a number of drugs have been developed that suppress HIV replication, thereby preventing the destruction of the immune system. Known as antiretroviral therapy, these drugs target different stages in the life cycle of HIV. There are four main classes of drugs used against HIV: nucleoside analogues, non-nucleoside reverse transcriptase inhibitors, protease inhibitors, and fusion inhibitors. Nucleoside analogues and non-nucleoside reverse transcriptase inhibitors use different mechanisms to block the action of the enzyme reverse transcriptase. Protease inhibitors interfere with protease, an enzyme vital to the formation of new HIV. When these drugs block protease, defective HIV forms that is unable to infect new cells. In 2003 the U.S. Food and Drug Administration approved the use of enfuvirtide, sold under the brand name Fuzeon. This drug belongs to a new class of drugs called fusion inhibitors, which prevent the binding or fusion of HIV to lymphocytes.

How HIV Causes Infections

HIV transmission occurs when a person is exposed to body fluids infected with the virus, such as blood, semen, vaginal secretions, and breast milk. The primary modes of HIV transmission are (1) sexual relations with an infected person (see Sexually Transmitted Infections); (2) sharing hypodermic needles or accidental pricking by a needle contaminated with infected blood; and (3) transfer of the virus from an infected mother to her baby during pregnancy, childbirth, or through breast-feeding.

When HIV enters the body, it infects lymphocytes, which are a type of white blood cell in the immune system. HIV uses its glycoproteins to attach itself to receptors on the surface of a lymphocyte. The outer envelope of HIV then fuses with the lymphocyte, enabling the HIV capsid to enter the lymphocyte itself. HIV commandeers the genetic material of the lymphocyte, instructing the cell to replicate more viruses. The newly formed viruses break free from the host, destroying the cell in the process. The new viruses go on to infect and destroy other lymphocytes.

Over a period that may last from a few months to up to 15 years, HIV may destroy enough lymphocytes that the immune system becomes unable to function properly. An infected person develops multiple life-threatening illnesses from infections that normally do not cause illnesses in people with a healthy immune system. Some people who have HIV infection may not develop any of the clinical illnesses that define the full-blown disease of AIDS for ten years or more. Doctors prefer to use the term AIDS for cases where a person has reached the final, life-threatening stage of HIV infection.