Parmacology Essay, Research Paper

Pharmacology

Pharmacology can be defined as the science of drugs used to prevent, diagnose, and treat a disease or condition. It deals with the interactions between living systems and chemical molecules. To ensure maximum effectiveness and reduce the potential for harm, the paramedic must have a thorough understanding of a drug and its actions before it is administered.

The historical events that led up to the history of pharmacology may have been as far back as 10,000 to 7000 B.C. Medical herbs were thought to be from animals, humans, minerals, and plants grown for medicine, such as gums, spices, and possibly narcotics mentioned in the bible.

A drug is any substance taken by mouth; injected into a muscle, blood vessel, or body cavity; or applied topically to prevent or treat a disease or condition. Four type of drug names are the Chemical name, which is a precise description of the drugs chemical compound; Generic name, which is usually a abbreviated form of the chemical name; Trade name, which is a copyright name designated by the drug company who invented and sells the medication; Official name, which is the name of the drug is followed by the initials USP or NF, which denotes its listing in one of the official publications. A paramedic s responsibilities in drug administration would include safe and therapeutically effective drug administration and are personally responsible for each drug they administer – legally, morally, and ethically.

There are many drug forms which can be aqueous solution, aqueous suspension, Emulsion, Spirits, Elixir, Tincture, fluid extract, Capsules, Tablets, Lozenges, Power are for oral use and Ampules, vials, or cartridges for parenteral route and lotion, ointment, paste, cream, aerosol for topical use. Drug allergies can be divided into four classifications based on the mechanism of the body s immune system. They are Type I (anaphylactic), Type II (cytotoxic), Type III (serum sickness), and Type IV (contact dermatitis) reactions.

Many agencies monitor and protect the country from controlled substances, the DEA is the nations sole legal drug enforcement agency, the PFDA of 1906 protects the public from mislabeled, altered, understudied drugs. It prohibits the use of false and misleading claims for medications and restricted the sale of drugs that may be potential for abuse. Public Health Services, the FTC is regulatory services. The International drug control board is responsible maintaining treaties, and obligating the government to intervene.

The Autonomic Nervous System

The Autonomic Nervous System is responsible for the control of involuntary actions (which are considered automatic). Almost every pre-hospital medication is responsible for affecting this system. The autonomic nervous system has two functional divisions. These divisions are the Sympathetic and the Parasympathetic systems. The Sympathetic system allows the body to function under stressful situations. This can be referred to as the Fight or Flight Response . The Parasympathetic system controls the vegetative functions, such as digestion, and this can be referred as the Feed and Breed or The Rest and Repose system.

The nervous systems the may be affected by certain drug therapy would be the Sympathetic and Parasympathetic systems. They function simultaneously and balance one another as mentioned earlier. With drug therapy, each separately or together can be affected. The route of drug administration can have an affect of drug absorption by rate and extent. These routes are enteral, parenteral, pulmonary, and topical. Enteral administration is known to be the safest and most convenient route. The distribution is the transport of a drug through the blood stream to various tissues of the body and ultimately to its site action. The dissolution of drugs is the rate of a solid drug that goes into a solution after it is ingested. The elimination takes place by biotransformation first and then by excretion through the kidneys, intestines, lungs, and mammary, sweat, and salivary glands. These are all part of the study of how the body handles a drug over a period called Pharmacokinetics. Now the study of how a drug acts on a living organism, to include the pharmacological response observed relative to the concentration of the drug at an active site in the organism is called Pharmacodynamic phase. The Pharmaceutical Phase is the science of dispensing drugs.

Drugs bind to drug receptors to produce their desired effect. The portion of the drug molecule (the active site) selectively combines or interacts with some molecular structure (the reactive site on the cell surface or within the cell) to produce the biological effect. The relationship of a drug to its receptor may be thought of as a key fitting into a lock. The drug is the key and the receptor is the lock. The drug variables that can influence interactions, include intestinal absorption, competition for plasma-protein binding, biotransformation, action at the receptor site, renal excretion, and altered electrolyte balance.

Preganglionic and Postganglionic nerve fibers transmit signals between the spinal cord in CNS and target organs. Sympathetic nerves are located from the lumbar region from the spinal cord. This system stimulates the adrenal medulla, releasing two hormones called epinephrine and norepinephrine (80% – epi, 20% – norepi). These each has two specific sympathetic receptors called the adrenergic receptor and the dopaminergic receptor.

The Adrenergic receptor has four types Alpha 1, Alpha 2, Beta 1, and Beta 2. Alpha 1 stimulates peripheral vasoconstriction, mild bronchodialation, and metabolism. Alpha 2 prevents the over release of norepinephrine. Beta 1 increases heart rate, contractility, automaticity, and conduction. Beta 2 causes vasodilatation and bronchodilation. Dopaminergic are not fully understood.

The Parasympathetic Nervous System runs from the brainstem and sacral regions. When the parasympathetic system is stimulated this would cause pupil constriction, secretion by digestive glands, increased smooth muscle of digestive tract, bronchoconstriction, and a reduction in heart rate and contractility. All parasympathetic ganglionic fibers use acetylcholine as a neurotransmitter for the synapses. . When you get the binding of acetylcholine at the nicotinic receptors, they produce an excitatory response in the effector organ. The neuroeffector junction is the synapse between the nerve and its target organ.

Medications that block the actions of the sympathetic and parasympathetic system are called patholytics or anticholinergics. The medications that stimulate the same response of that system are called pathomimetics or cholinergics. Emetics are used to induce vomiting to rid the body of an over exposure of a drug. Romazicon is used in the prehospital setting for the reversal of Benzodiazepines. Benzodiazepine is a schedule IV controlled substance that is used for inducing sedation. Who would of thought that grapefruits may inhibit liver enzymes and boost the blood level when verapamil is used, which means the therapeutic index is multiplied by One Thousand!

The Liver is responsible for the metabolism of drugs and the Kidneys are responsible for the excretion of the drugs. The brain has a protective coating called the Blood Brain-Barrier. This protects the brain from the passage of certain drugs into certain body sites. It only permits lipid soluble drugs into the brain and cerebrospinal fluid.

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