A-Z Classification
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    Nervous System/Adrenergic & Blocking Agents
    Nervous System Adrenergic (Sympathomimetic) Agents are used to treat breathing disorders such as Asthma, Emphysema, or Chronic Bronchitis. Nervous System Adrenergic Blocking (Sympatholytic) Agents are used to treat symptoms of migraine headaches. 

    Neurons communicate with other cells throughout the body by releasing chemicals, such as epinephrine and norepinephrine, into the synapse exciting receptors. Another neuron responds to the chemicals in the synaptic junction by sending electrical impulses to various organs. Stimulation from epinephrine and norepinephrine results in cerebral vessel dilatation, increased heart rate and strength, peripheral blood vessel constriction, airway relaxation, decreased intestinal activity, bladder relaxation, urinary sphincter contraction, and increased production of saliva. A feedback system limits excess release of chemicals to prevent prolonged stimulation of the various organs.

    In diseases, such as asthma, bronchitis, or emphysema, airways become constricted due to smooth muscle spasms and inflammation so breathing becomes hampered. Migraines occur when cerebral vessels constrict, spasm, and eventually dilate. The Migraine Headache pain is caused by continual cerebral vessel dilatation.

    Sympathomimetic (Adrenergic) Agents, like Bronchodilators, relax the smooth muscles and dilate the airways to improve breathing. Bronchodilators, such as Adrenalin, Epinephrine, Alupent, or Albuterol, imitate epinephrine and norepinephrine or trigger the release of more natural epinephrine and norepinephrine for airway dilatation. Pseudoephedrines relieve congestion due to inflammation and assist in opening the air passageways.

    Sympatholytic (Adrenergic Blocking) Agents, like Cafergot, can be used to treat migraine headaches. They inhibit the chemical release of epinephrine or norepinephrine resulting in constriction of the already dilated cerebral vessels.

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    Nervous System/Anticonvulsants, Sedatives, & Hypnotics
    Nervous System Anticonvulsants, Sedatives, & Hypnotics are used to depress brain activity and treat sleeplessness, anxiety, nervousness, and seizures. 
    The brain consists of many cells, called neurons, that communicate with other cells throughout the body. Neurons are made of three major parts: the cell body, axon, and dendrite. To communicate messages, the neuron transmits electrical impulses that trigger chemicals to be released. Chemicals (also known as neurotransmitters) such as norepinephrine, dopamine, serotonin, and others, are released into a region between two neurons, called the synapse. Another neuron responds to the chemicals in the synaptic junction by inhibiting or sending the electrical signal. The electrical signals in the brain are usually organized to produce smooth movements. Once the receiving cell has responded, the chemicals remaining in the synaptic junction are either broken down by enzymes or retaken up by the transmitter cell.

    Normal sleep occurs with fatigue and reduced stimulation. However, if excessive electrical impulses are triggered, disorganization, increased chemical release, and altered brain functioning occurs resulting in sleeplessness (or insomnia). Anxiety can be caused by unorganized or excessive electrical impulses producing tensions, inability to relax, shakiness, sweating, racing heart, feelings of apprehension, lack of concentration, insomnia, and other negative effects. Epilepsy, or seizures, can result from disorganization of electrical impulses, producing uncontrolled muscle activity, spasms, unconsciousness, or loss of bowel or bladder control.

    Anticonvulsants, Anxiolytics, Sedatives, and Hypnotics can be used to treat anxiety, insomnia, or seizures. Neuronal excitability is diminished by these medications by decreasing impulse transmission and returning body movements to a more organized smooth state, relaxation, or sleep. The medications decrease the spread of the neuronal activity, reorganizing impulse formation, chemical release or response, synaptic response, or receiver cell response so messages are acted upon appropriately.

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    Nervous System/Antidepressants, Tranquilizers & Others
    Nervous System Antidepressants, Tranquilizers and Other Agents alter the chemicals in the brain to treat symptoms of Depression, Manic-Depression, Psychosis or Schizophrenia. 
    The brain consists of many cells, called neurons, that communicate with other cells throughout the body. Neurons are made of three major parts: the cell body, axon, and dendrite. To communicate messages, the neuron transmits electrical impulses that trigger chemicals to be released. Chemicals (also known as neurotransmitters) such as norepinephrine, dopamine, serotonin, and others, are released into a region between two neurons, called the synapse. Another neuron responds to the chemicals in the synaptic junction by excitement or with inhibition. Once the receiving cell has responded, the chemicals remaining in the synaptic junction are either broken down by monoamine oxidase enzymes or retaken up by the transmitter cell.

    Alterations in neuronal cell function can influence psychological behaviour. Depression can be caused by decreased chemical levels, especially serotonin and norepinephrine. On the other hand, Psychosis, Schizophrenia, or other mental illnesses can be caused by increased chemical (mainly dopamine) activity in the synapse. Manic-Depression, characterized by severe mood swings from elation to depression, may be caused by variable chemical extremes in the synapse and shifting inside the neuron.

    Antidepressants, specifically Tricyclics and MAO Inhibitors, can be used to treat depression. Tricyclics redirect excitatory chemicals for use in the synapse to stimulate or excite other neurons. MAO Inhibitors block enzymes that break down chemicals, allowing further activity or excitement to occur in the synapse.

    Tranquilizers, specifically Phenothiazines, cause calming effects or sedation for Psychosis, Schizophrenia, or other mental illnesses. They decrease the transmission of the nerve signals by blocking the chemicals, especially dopamine, at targeted receptor sites.

    Antimanic Agents, like Lithium, can be used to treat Manic-Depression by altering the elements in the cell, stabilizing nerve impulse transmission and chemical release.

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    Nervous System/Cholinergic and Anti cholinergic Agents
    Nervous System Cholinergic and Anticholinergic Agents are used to stimulate or reduce certain body functions and movements. They are used in the treatment of Urinary Retention, Myasthenia Gravis, Diarrhoea, Cramps, Nervous Stomach, Ulcers, or Parkinson's Disease.
    The Parasympathetic Nervous System is made up of neurons that communicate with other cells in the body by releasing chemicals into the synapse to excite receptors and send electrical impulses. The chemicals, primarily Acetylcholine, alter the system, resulting in decreased heart rate and strength, airway and pupil constriction, muscle and bladder contraction (with sphincter relaxation), increased intestinal wall activity, and an increase in saliva and insulin secretion. Once the receiving cells respond, any acetylcholine still in the synaptic junction is broken down by acetylcholinesterase that temporarily diminishes the effects.

    Prolonged diminished acetlycholine effects may cause disorders like urinary retention, gastric reflux, or Myasthenia Gravis. Urinary retention can occur due to lack of stimulation to the bladder muscle and lack of sphincter relaxation. Gastric reflux occurs when stomach secretions and food are forced up the digestive tract instead of down to be digested. Myasthenia Gravis is due to weakened skeletal muscles causing decreased functioning.

    Cholinergic (Parasympathomimetic) Agents, like Bethanechol, Mestinon, or Prostigmin, can be used to stimulate bladder contraction, digestive tract movement, and skeletal muscle movement. Cholinergic Agents imitate Acetylcholine or inhibit acetylcholinesterase to prevent acetylcholine breakdown.

    Parkinson's Disease can occur when an imbalance of acetylcholine and dopamine neurotransmitters result in tremors or shaking, increased muscle tone and rigidity, expressionless face, drooling, and an unstable standing position. Increased neurotransmission occurs when excitable acetylcholine levels are raised and relaxant dopamine levels are decreased. Digestive disorders can occur due to acetylcholinergic effects of increased stomach or intestine activity causing Peptic Ulcers, Diarrhoea, Irritable Bowel Syndrome, Cramps, or Nervous Stomach.

    Parkinson's Disease symptoms can be reduced with Anticholinergic Agents, such as Cogentin or Artane, which oppose acetylcholine actions to regain balance with dopamine. Anticholinergic Agents relax muscles, decreasing tremors, shaking, and rigidity. They also decrease salivary secretions. Anticholinergic Agents, like Belladonna, Anaspas, Levsin, Bentyl, and Rubinul, inhibit acetlycholine and decrease stomach and intestinal activity.

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    Nervous System/Skeletal Muscle Relaxants
    Nervous System Skeletal Muscle Relaxants prevent muscle spasms that can occur with Strains, Sprains, Spinal Cord Injury, or Multiple Sclerosis. 
    Skeletal Muscles, attached to bones, provide body movement or contraction in response to nerve stimulation. The brain and spinal cord communicate through nerves to muscle cells for contraction. The nerve impulses release chemicals (mainly acetylcholine) at the nerve-muscle junction (called synapse), causing excitement and sending electrical messages to the rest of the muscle group to shorten or contract. Acetylcholine remaining in the junction after the muscle contracts is destroyed by other chemicals allowing muscle relaxation. The muscle movements normally are voluntary, conscious, and smooth.

    If chemical release continues, skeletal muscles remain contracted, resulting in involuntary muscle spasms, causing decreased functioning and pain. This can occur with spinal cord injury, strains or sprains of muscles, or with a disease like Multiple Sclerosis.

    Skeletal Muscle Relaxants can decrease muscle spasms by restricting the nervous pathway to the muscle. This interruption of impulse transmission can occur in the brain, spinal cord, neuron, nerve-muscle junction, or in the muscle. Most Skeletal Muscle Relaxants act by depressing the brain pathways or interfering with chemical activity in the nerve-muscle junction. However, Dantrium directly inhibits muscle cellular calcium movement to prevent contraction.

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    Nervous System/Stimulants
    Nervous System Stimulants are used to treat Obesity, Narcolepsy, or Attention Deficit Disorder. These drugs, often also called Stimulants and Appetite Suppressants, make the brain active, resulting in alertness, increased attention span, and decreased appetite.  
    Appetite and alertness are controlled by the brain stem. More specifically, the reticular activating system, the thalamus, and the hypothalamus signal the release of chemicals (called norepinephrine) that trigger electrical activity resulting in alertness and suppressed appetite. Other environmental stimuli, such as smell, blood sugar, physical fitness, or fatigue can influence the release of these chemicals.

    If the brain stem malfunctions, chemical release may be limited and cause one of the following diseases. Obesity can occur when the satiety centre in the brain lacks stimulation to cease eating or transmit the feeling of being full. Narcolepsy is the tendency to fall asleep during the day. Attention Deficit Disorder, a childhood disease, occurs when the brain chemicals are disorganized and not read appropriately by the brain, causing decreased attention span and concentration, increased impulsiveness, and, occasionally, hyperactivity

    Cerebral Stimulants, such as Amphetamines, Nonamphetamine Stimulants, or Appetite Suppressants, can be used for Narcolepsy, Obesity, and Attention Deficit Disorder. Cerebral Stimulants activate the brain to release chemicals (norepinephrine) and enhance electrical activity resulting in alertness, euphoria, increased attention span or concentration, and decreased appetite.

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    Pain Agents
    Pain Agents are also known as Analgesics and are manufactured in different strengths to control varying degrees of pain. Some of these medications (Antipyretics) also reduce fever. 
    To communicate pain, nerves transmit electrical impulses that trigger chemical release (mainly prostaglandins) into a region called the synapse. Another nerve cell responds to the chemicals in the synaptic junction and transmits the pain message to the brain.

    Brain cells, called neurons, communicate with other cells throughout the body and release a natural opiate-like chemical (endorphins) to excite opioid receptors on the end of nerve cells. Endorphins interrupt the pain message travelling to the brain by inhibiting release of other neurotransmitters. Pain is a very complex phenomenon that involves physiological, psychological, cultural, and other factors. Pain can be a warning symptom or protective mechanism warning the individual of a problem.

    If pain is not inhibited by the natural endorphins released in the body, medications can be used to decrease pain sensitivity or increase pain tolerance. The need for Pain control will vary among individuals. Analgesics are drugs used to relieve the symptoms of pain. Nonsteroidal Anti-Inflammatory Agents (NSAIDS), are further divided into those made of salicylate (like Aspirin) and those constituted of non-Aspirin compounds, (like Ibuprofen). NSAIDS decrease pain sensation by generally inhibiting prostaglandin production, which is responsible for inflammation. This, in turn, also decreases redness, heat, or swelling. Refer to ANTI-INFLAMMATORY AGENTS and DENTAL AGENTS for more information. NSAIDS also alter the hypothalamus in the brain, which decreases temperature. Additionally, Aspirin and Aspirin compounds prevent blood clotting and can be useful to prevent strokes and other diseases.

    Narcotic Analgesics and Acetaminophen act directly, like natural endorphins, to inhibit prostaglandins in the brain and spinal cord, altering the pain perception. Narcotic Analgesics, such as Morphine, Meperidine, Codeine, or Methadone, are also called opioids and function by combining with opiate receptors at nerve endings to block pain signals.

    Opiate Antagonists, such as Naloxone or Narcan, reverse action of narcotic drugs and natural endorphins in nerve endings. These medications can be used for narcotic overdose or reversal of respiratory depression caused by opiates.

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    Respiratory Antitussives, Expectorants, & Mucolytics
    Respiratory Antitussives, Expectorants, and Mucolytics are used to treat secretions and cough occurring with the common cold, allergies, hay fever, sinus infection, bronchitis, pneumonia, asthma, or emphysema.        
    Breathing allows oxygen to be exchanged with carbon dioxide in the alveoli of the lungs to give the cells energy. Air enters into the nose and throat for natural humidifying and purifying before being sent to the lungs. Tiny hairs inside the nose and upper respiratory tract (called cilia), act as a screen to foreign particles. Specialized cells in the respiratory tract produce mucus to stop or trap any foreign particles that slip past this hair screen.

    If foreign particles make their way past the cilia and into the lower respiratory tract, coughing may occur to defend the passageways. This is a natural defensive reflex to rid the respiratory tract of foreign particles or secretions so air can be transported freely. Cough is initiated locally by stimulation or irritation of receptors in the respiratory tract walls that send messages to the central respiratory centre in the medulla of the brain.

    Failure of mucus production or cough mechanisms may allow foreign particles to invade and cause illness. Illnesses such as the common cold, asthma, bronchitis, allergies, hay fever, sinusitis, emphysema, or pneumonia cause symptoms of increased cough or mucus production. A productive cough to rid the airways of mucus or foreign particles can be irritating, painful, or exhausting. Non-productive or dry cough usually occurs due to irritation of the airways but does not clear secretions.

    ANTITUSSIVES, EXPECTORANTS, AND MUCOLYTIC AGENTS can reduce discomfort of respiratory illness by decreasing the symptoms of cough or mucus. The cause of cough or increased mucus, such as inflammation or infection, is typically treated first. Then, Mucolytics, such as Acetylcysteine, are usually given by inhalation for direct action on the respiratory tract to thin mucous secretions by breaking them up. This usually makes it easier to expel the secretions. Expectorants, such as Guaifenesin, Iodinated Glycerol, or Potassium Iodide,, increase production of mucus to trap foreign particles and excrete them by a productive cough.

    Antitussives can suppress a non-productive cough. Narcotic Antitussives, such as Codeine, Hydrocodone, or Hydromorphone act centrally to depress the medullary respiratory centre in the brain to decrease cough. Some of the Narcotic Antitussives may also decrease the ciliary action. Synthetic Antitussives, like Dextromethorphan, act like Narcotic Antitussives by suppressing the brain but have fewer adverse reactions. Nonnarcotic Antitussives, such as Benzonatate, act locally to numb receptor sites in the respiratory tract wall so cough messages cannot be sent to the brain. Many of these medications are used in combination and may occur in either prescription or non-prescription preparations.

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    Respiratory Smooth Muscle Relaxants
    Respiratory Smooth Muscle Relaxants are used to open air passageways and limit such symptoms as shortness of breath, coughing, or wheezing that are often associated with Allergies, Infections, Asthma, Pneumonia, or Emphysema. 
    Respiration or breathing is a two way process consisting of inspiration and expiration. Air, containing gasses like oxygen, is transported into the body during inspiration. Carbon dioxide gas is transported out of the body during expiration. The nose, throat and tracheobronchial tree move air to and from the lungs where gas exchange occurs between the alveoli of the lungs and the blood. The blood then circulates oxygen to cells to use as energy. Carbon dioxide is released back into the blood stream, carried to the alveoli, then released back into the air.

    The respiratory centre of the brain regulates movement of the respiratory muscles and walls of the bronchi leading to the lungs. Nerves transmit impulses from the brain to constrict the muscles and bronchial walls so less air is able to enter into the body for gas exchange. Normally, the respiratory muscles are flexible and respond to a feedback system by dilating when carbon dioxide accumulates.

    Certain disease processes of the upper and lower respiratory tract decrease the flexibility of the respiratory muscles and result in restricted gas exchange between the alveoli of the lung and the blood stream. Inflammation of the tracheobronchial tree, due to allergy or infection, causes increased mucus production and swelling. The upper air passageways become restricted due to this mucus and swelling and air movement is hampered. This occurs in hay fever, common cold, tracheitis, or bronchitis.. Pneumonia, Asthma, and Emphysema are diseases that decrease the flexibility of the lower passageways due to inflammation, making it difficult for the gas exchange between the alveoli and the blood stream to occur. Constriction or decreased flexibility of the respiratory muscles can cause shortness of breath, coughing, wheezing or other symptoms.

    Respiratory Smooth Muscle Relaxants, such as Xanthines,, convert to theophylline that inhibits an enzyme (phosphodiesterase) to directly relax smooth muscles of the respiratory tract and alter the respiratory centre in the brain. With relaxation, breathing passages open so air can be transported and effective gas exchange can occur. If constriction due to muscle wall swelling occurs, Xanthines are combined with Expectorants, Decongestants, Antihistamines, or other medications to allow unrestricted gas exchange and adequate oxygenation.

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    Serums, Toxoids, & Vaccines
    Serums, Toxoids, & Vaccines provide immunity against Measles, Mumps, Rubella, Tetanus, Hepatitis, and others. In contrast, other drugs may be given to delay immunity and prevent Organ Rejection. 
    Pathogens, such as bacteria and viruses, frequently attack the body. Typically, pathogens enter the body and release toxins to invade and destroy other cells. The normal body response is to destroy and eliminate the pathogens or the cells they occupy.

    When normal body defense systems cannot eliminate the pathogens, they multiply and continue to release toxins, damaging normal body cells. This can result in infectious disease, producing minor symptoms such as fever, fatigue, body aches, or more severe symptoms. In response, the body usually produces antibodies to resist future invasion by that specific virus or bacteria. The body can also react by producing substances against other foreign tissue like transplanted organs. This is called Organ rejection.

    SERUMS, TOXOIDS, AND VACCINES artificially protect the body against diseases caused by specific pathogens. Toxoids, such as MMR or Tetanus Toxoid, contain altered bacteria and are given to fight off invasion by bacterial toxic substances and prevent harmful effects. Vaccines are altered viruses that are given to fight off specific viral infections, such as Hepatitis B or Typhoid Fever. Toxoids and Vaccines take time to be effective against the pathogen but last for a long time. Serums are given to establish immediate protection against disease but are short acting. They are made from blood of humans or animals that have recovered from the disease. In contrast, Immunosuppressants, like Imuran or Sandimmune, prevent the immune response to control organ rejection and other diseases.

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    Skin & Mucous Membrane Agents
    Skin & Mucous Membrane Agents and Enzymes are applied directly to the skin or mucous membranes to treat conditions such as Dry or Oily Skin, Dandruff, Acne, Psoriasis, or even some Respiratory conditions (Asthma or Cystic Fibrosis).
    The largest organ in the human body is the skin that covers and protects the body. Components of the skin include the epidermis and the dermis. The epidermis constantly regenerates and replaces cells, while the dermis is composed of stretchable connective tissues, blood vessels, nerves, and glands. The skin functions as a covering and protects the organs and tissues within the body. Skin also helps regulate temperature, excretes water, and serves as a touch sense receptor. Mucous membranes, such as those in the nose or throat, are epithelial cells that line body cavities with exterior openings and frequently secrete mucus.

    Disorders can occur due to alterations in the continuous skin and mucous membrane coverings or glands within the skin. They include Acne, psoriasis, dry or oily skin, and dandruff. Acne occurs when the oil secreting sebaceous glands over produce and plug hair follicles. Psoriasis occurs when new cell production is greater than the sloughing of old cells causing an accumulation and inflamed patchy area. Dandruff is the accumulation of dead cells on the scalp forming scales that are shed. Additionally, cavities coated with mucous membranes can produce mucus plugs.

    SKIN AND MUCOUS MEMBRANE AGENTS and ENZYMES act on the surface of the skin and mucous membranes. They lubricate or remove excess oil, encourage skin cell multiplication or loosen and remove old cells, and protect the skin from sun, fade dark spots, or restore colour.

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    Vitamins & Caloric Agents
    Vitamins and Caloric Agents are used in the prevention and treatment of Malnutrition or Vitamin Deficiency.   
    A balanced intake of food is needed to provide vitamins and nutrients. Food is then digested, absorbed, and circulated as glucose or other chemicals to all cells of the body to use for energy, growth, and repair. Because nutrients cannot be adequately stored, frequent replenishment is necessary to meet cell needs.

    With inadequate nutritional intake, malabsorption, or other illnesses, malnutrition and vitamin deficiency occur, resulting in various states of disease. This can cause impaired growth and impaired healing, as well as numerous cellular changes.

    VITAMINS and Caloric Agents provide the nutrients absent from daily consumption to maintain normal metabolic function, growth, and repair. They also treat diseases caused by impaired daily nutrition.


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