Spasm

Spasm, involuntary and abnormal violent contraction of muscles or muscle tissue. Tonic spasm, or cramp, is characterized by an unusually prolonged and strong muscular contraction, with relaxation taking place slowly. The extreme example of tonic spasm is tetanus, in which the spasms are so violent and so enduring that they may paralyze breathing. In the other form of spasm, called clonic spasm, contractions of the affected muscles take place repeatedly, forcibly, and in quick succession, with equally sudden and frequent relaxations. The most typical examples of clonic spasm are epilepsy and convulsive hysteria.

The medicines used to counteract spasmodic muscular activity are termed antispasmodics. These are used in certain surgical procedures because they block transmission of nervous impulses to the muscles. Derivatives of hemlock and some 50 other plants have a relaxing effect on muscles.

Emphysema

Emphysema, progressive respiratory disease characterized by coughing, shortness of breath, and wheezing, developing into extreme difficulty in breathing, and sometimes resulting in disability and death. Although the exact cause is unknown, bronchial spasm, infection, irritation, or a combination of the three seem to be contributory. The highest degree of occurrence is among heavy cigarette smokers, especially those exposed to polluted air. Children who suffer from bronchitis or asthma are also susceptible.

In the course of the disease the passages leading to the air sacs of the lungs become narrowed. Air is trapped in the sacs, and the tissues of the lungs lose their natural elasticity and undergo destructive changes. Symptoms akin to the common cold or asthmatic wheezing may result. As the disease progresses the volume of residual air trapped in the lungs increases, and the volume of each breath decreases. The lungs increase in size, and in severe cases the patient develops a characteristic “barrel chest.” The lungs become unable to supply enough oxygen to the body tissues. This reduction in oxygen intake causes the heart to pump faster; consequently, the heart becomes strained. Excessive carbon dioxide in the blood gives the patient a bluish skin color.

Elephantiasis

Elephantiasis, disease of the lymphatic system, characterized by an enormous enlargement of the infected area. The hardened skin of this area resembles the hide of an elephant. The disease is usually the result of blockage of the lymphatic system by threadlike filarial worms, usually Wuchereria bancrofti. The parts of the body most frequently affected are the limbs and the genitals. The disease is treated with the antifilarial drug diethylcarbamazine (Hetrazan) and with surgery.

Dysentery

Dysentery, acute or chronic disease of the large intestine of humans, characterized by frequent passage of small, watery stools, often containing blood and mucus, accompanied by severe abdominal cramps. Ulceration of the walls of the intestine may occur. Although many severe cases of diarrhea have been called dysentery, the word properly refers to a disease caused by either a specific amoeba, Entamoeba histolytica, or a bacillus that infects the colon.

Amoebic dysentery, caused by the parasite Entamoeba histolytica, is endemic in many tropical countries, but is attributable more to unsanitary conditions than to heat. It is most commonly spread by water or contaminated, uncooked food or from carriers. Flies may carry the cysts to spread the amoeba from the feces of infected persons to food. Various drugs, including metronidazole, ementine, and iodine-containing preparations, have been useful in treating severe cases of the disease.

Bacillary dysentery is caused by certain nonmotile bacteria of the genus Shigella. This dysentery is usually self-limiting and rarely manifests the more severe organ involvements characteristic of amoebic dysentery. Bacillary dysentery is spread by contaminated water, milk, and food. Feces from active cases and those from healthy carriers as well contain immense numbers of the disease-producing bacteria. Flies carry the bacteria on their feet or in their saliva and feces and deposit them on food; ants are also believed to spread the disease. Proper replacement of fluid is important in treating. Sulfonamides, tetracycline, and streptomycin were effective in curing acute cases until drug-resistant strains emerged. Chloramphenicol is sometimes used to treat these strains. Quinolones such as norfloxacin and ciprofloxacin are also effective against Shigella infection.

Drowning

Drowning, death by suffocation due to the presence of water in the respiratory system.

Resuscitation by artificial respiration can prevent the death of a person with water in the lungs if instituted quickly. Because of the constant need of body tissues for oxygen, even a few minutes of suffocation can result in brain damage or death. The exception to this appears in persons who have been submerged in cold water. Some victims have been completely revived, without brain damage, after having been underwater for as long as a half hour. This phenomenon, the so-called diving reflex, has long been observed in sea mammals. Activated when the face is plunged into water below 21° C (70° F), it slows body processes so that oxygen-bearing blood is diverted to the heart and brain.

Doxycycline

Doxycycline, antibiotic drug used to treat various types of bacterial infections including urinary tract infections, traveler’s diarrhea, Rocky Mountain spotted fever, trachoma, and syphilis. It is also sometimes used to treat early Lyme disease and to prevent the spread of malaria. Doxycycline belongs to a group of antibiotics known as tetracyclines. It works by interfering with the invading bacteria’s ability to form essential proteins, thereby halting their growth.

This drug is available by prescription in capsules, tablets, and liquid forms, which are taken orally, although one form of liquid is made for injection. Typical dosages range from 100 to 200 mg per day, taken in one or two doses, with a recommended maximum dose of 300 mg a day. Unless this drug causes stomach upset, it should be taken on an empty stomach (one hour before or two hours after a meal) with a full glass of water. Doxycycline usually relieves symptoms after 48 hours of treatment, but it should be taken for the entire prescribed length of time to avoid recurrence of infection.

Patients with liver disease and pregnant or breast-feeding women should not use this drug. It may be taken by children over the age of eight at a dosage based on body weight. Possible side effects include diarrhea, nausea, vomiting, skin rash, itching, light sensitivity, headache, facial swelling, chest pain, difficulty swallowing, or bulging forehead (in infants). Children may develop discolored teeth, especially with long-term use.

Doxycyline may interact adversely with antacids and other common gastrointestinal medications, birth control pills, barbiturates, blood-thinners, penicillin, phenytoin, sodium bicarbonate, and carbamazepine.

Brand Names:Doryx, Vibramycin, Vibra-Tabs, Bio-Tab

Psychoactive Drugs

Psychoactive Drugs, chemical substances that alter mood, behavior, perception, or mental functioning. Throughout history, many cultures have found ways to alter consciousness through the ingestion of substances. In current professional practice, psychoactive substances known as psychotropic drugs have been developed to treat patients with severe mental illness.

Psychoactive substances exert their effects by modifying biochemical or physiological processes in the brain. The message system of nerve cells, or neurons, relies on both electrical and chemical transmission. Neurons rarely touch each other; the microscopic gap between one neuron and the next, called the synapse, is bridged by chemicals called neuroregulators, or neurotransmitters. Psychoactive drugs act by altering neurotransmitter function. The drugs can be divided into six major pharmacological classes based on their desired behavioral or psychological effect: alcohol, sedative-hypnotics, narcotic analgesics, stimulant-euphoriants, hallucinogens, and psychotropic agents.