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A drug can be any substance that, when administered to living organisms, produces a change in function. Thus, substances such as water, metals (iron), or insecticides can be classified as drugs. However, the term drug commonly means any medication that is used for diagnosing, curing, or treating disease Every drug produces its intended effect, or therapeutic effect, along with other effects. The therapeutic use(s) of any drug is referred to as the drug indication, meaning Indications for use.
The term contraindication refers to the tuition or circumstance when a particular drug should not be used. Side effects are more of a nuisance than they are harmful Adverse effects are also undesired effects, but these are effects that may be harmful Toxic effects, or toxicity, implies drug poisoning, the consequences of which can be extremely harmful and may be life-threatening. The site of action of a drug is the location within the body where the drug exerts Its therapeutic effect Mechanism of action explains how a drug produces Its effects.
Drugs that bind to specific receptors and produce a drug action are called Zionists. Morphine is an example of an agonies. Drugs that bind to specific receptors and inhibit agonies drug action or cellular functions are called antagonists. Potency is a measure of the strength, or concentration, of a drug required to produce a specific effect therapeutic index (T’) is a ratio of the OLDS to the DEED of a drug Chapter 2 – Pharmaceutics and factors of individual variation availability: percentage of the drug dosage that Is absorbed. Rug absorption: entrance of a drug into the bloodstream from Its site of administration. Drug distribution: passage of a drug from the blood to the tissues and organs of the body. Rug excretion: elimination of the drug from the body. Drug metabolism: the enzymatic beatifications of a drug into metabolites. Drug microcosms metabolize system (DMS): group of enzymes located primarily in the liver that function to metabolize (beatifications) drugs. Enzyme Induction: increase In the amount of drug-metabolize enzymes after repeated administration of certain drugs. Alfa-life: time required for the body to reduce the amount of drug in the plasma by one-half. Loading dose: initial drug dose administered to rapidly achieve therapeutic drug concentrations. Maintenance dose: dose administered to maintain drug blood levels in the therapeutic range. Pharmaceutics: describes the processes of drug absorption, drug distribution, drug metabolism, and drug excretion. Chapter 3 – Geriatric Pharmacology Each of the pharmaceutics processes??drug absorption, drug distribution, drug metabolism, and drug excretion??is affected to some degree by the aging process.
With age there is a decrease in blood flow to the intestinal tract, reduced intestinal absorptive surface area, a decrease in gastric acid secretion, and a decrease in intestinal motility. The percentage of lean body mass (muscle) and the percentage of total body water decrease The percentage of body fat (adipose tissue) Increases with age the rate of drug metabolism decreases with age, although there Is much microcosms metabolize enzymes (DMS) reduce the rate of drug metabolism The elderly are often more sensitive to drugs that depress the central nervous system.
Sedatives, hypnotics, mentality agents, antispasmodics, and antidepressant drugs fifteen cause excessive pharmacological and adverse effects in the elderly Pharmacology for the Peripheral Nervous System The peripheral nervous system includes the somatic and autonomic nervous systems. The somatic nervous system is concerned with sensation and voluntary movement.
The autonomic nervous system controls blood pressure, heart rate, gastrointestinal activity, and glandular secretions Chapter 5 – intro to Autonomic Nervous System The primary function of the central nervous system is to control and coordinate the activity of all the systems in the body. The overall activity of the nervous system at any moment depends on neural communication (via nerve impulses) among many areas of the body. The autonomic nervous system is a subdivision of the central nervous system that regulates the activities of the internal organs and glands.
The internal organs and glands are under involuntary or unconscious control MANS is composed of the parasympathetic and sympathetic divisions. The nerves of the parasympathetic division (also known as the correctional division) originate from the brain (cranial nerves 3, 7, 9, and 10) and spinal cord (sacral nerves SO to SO). The cranial nerves supply the internal organs and glands of the head, thoracic cavity, and upper portion of the abdominal cavity. The sacral nerves supply the lower portion of the abdominal cavity and the pelvic cavity. The origin and distribution of parasympathetic nerves are shown in Figure 5. 1 .
The nerves of the sympathetic division (known as the thermonuclear division) originate from the thoracic and lumbar spinal nerves (TTL to LA). The thoracic nerves supply the internal organs and glands of the head, thoracic cavity, and upper abdominal cavity. The lumbar nerves supply the lower portion of the abdominal cavity and the pelvic cavity. In the parasympathetic nervous system, the neurotransmitter released at the ganglia and the postcolonial nerve endings is catecholamine (ACH). In sympathetic nerves, the neurotransmitter released at the ganglia is also ACH, but at the postcolonial nerve endings, it is morphogenesis (EN).
Nerves that release catecholamine are referred to as choleric, while nerves that release morphogenesis are referred to as adrenaline. The cardiac and smooth muscle membrane sites where these neurotransmitters act are known as the choleric (also known as musician) receptors (ACH) and the adrenaline receptors (EN) sympathetic division, the postcolonial neurons release EN, which stimulates the adrenaline receptors. The adrenaline receptors are divided into alpha and beta receptors The definition or action of alpha-I receptor stimulation is the contraction of smooth muscle; for example, vasoconstriction of blood vessels.
Beta-I receptors are located mainly on the heart and mediate cardiac stimulation, an increase in heart rate and force of contraction. Beta-2 receptors are located on smooth muscle and produce relaxation of smooth muscle; for example, relaxation of respiratory smooth muscle (procrastination). Chapter 6 – Drugs that affect the sympathetic nervous system adrenaline neuronal blocker: drug that acts at the neuronal nerve endings to reduce adrenaline receptors. Alpha-I adrenaline blocker: drug that blocks the alpha-I effects of EN and PEP. Alpha-I adrenaline receptor: receptor located on smooth muscle that ideates smooth muscle contraction. Alpha-2 adrenaline receptor: receptor located on adrenaline nerve endings that reduces the release of EN. Beta-I adrenaline receptor: receptor located on the heart that increases heart rate and force of contraction. Beta-2 adrenaline receptor: receptor located on smooth muscle that relaxes smooth muscle when stimulated. Catecholamine: refers to morphogenesis, epinephrine, and other psychosomatic compounds that possess the catechist structure. False transmitter: substance formed in nerve endings that mimics and interferes with the action of the normal neurotransmitter. Instinctive beta- adrenaline blocker: drug that blocks both beta-I and beta-2 adrenaline receptors. Nonconsecutive beta-adrenaline drug: drug that stimulates both beta-I and beta-2 receptors. Selective beta-I adrenaline blocker: drug that blocks only beta-I receptors. Selective beta-2 adrenaline drug: drug that stimulates only beta-2 receptors at therapeutic doses. Sympathetic: refers to the action of an adrenaline blocking drug or an action that decreases sympathetic activity. psychosomatic: refers to the action of an adrenaline drug or an action that increases sympathetic activity.
The rugs used to affect sympathetic activity are classified as adrenaline drugs (Zionists) that increase sympathetic activity and adrenaline blockers (antagonists) that decrease sympathetic activity. Adrenaline drugs are used to increase blood pressure, stimulate the heart, and produce procrastination. Adrenaline blockers are primarily used to lower blood pressure and reduce cardiac stimulation in conditions where there is excessive sympathetic activity. Psychosomatics are adrenaline drugs (alpha and beta Zionists) that produce effects that are similar to stimulating or mimicking the sympathetic nervous system. Psychoanalytic refer to adrenaline blocking drugs (alpha, beta, and neuronal blockers) that antagonize or decrease sympathetic activity Psychosomatic drugs, including EN and PEP, that produce contraction of smooth muscle by stimulating the alpha-I adrenaline receptors are referred to as alpha-adrenaline drugs. Drugs, including PEP, that both stimulate the heart (stimulate beta-I receptors) and cause relaxation of smooth muscle (stimulate beta-2 receptors) are referred to as Nonconsecutive beta-adrenaline drugs.
PEP is one of the few substances that stimulates all alpha and beta receptors. There are also beta- derringer drugs that selectively stimulate only the beta-2 receptors at therapeutic doses. These drugs are referred to as the selective beta-2 adrenaline drugs and are used primarily as prognosticators Sympathetic drugs that block the alpha effects of EN and PEP are known as the alpha-adrenaline blockers. Most alpha blockers available today only block the alpha-I receptor (relaxation of smooth muscle).
Drugs that block both the beta-I and beta-2 effects of PEP are known as the Nonconsecutive beta-adrenaline blockers. Drugs that block only beta-I receptors are known as selective beta-I adrenaline blockers. The effect of these alpha- and beta-blockers is to decrease sympathetic activity, especially in the cardiovascular system. The blocking drug competes with EN or PEP for the receptor sites Drugs that act at the adrenaline nerve endings to reduce the formation or release of EN are known as the adrenaline neuronal blockers The most important clinical effect produced by the of smooth muscle.
This includes vasoconstriction of most blood vessels, contraction of sphincter muscles in the gastrointestinal (inhibits movement of intestinal contents) and urinary (restricts passage of urine) tracts, and contraction of ocular muscles that causes dilation of the pupil of the eye (madrigals). Alpha drugs are administered intravenously in hypertensive states; for example, after surgery, to increase blooded pressure and maintain circulation. Vasoconstriction of blood vessels in mucous membranes of the nasal sinuses produces a decongestant effect The beta- adrenaline drugs have a selective action to stimulate beta receptors.
With the exception of EN and PEP, most beta drugs produce very few alpha effects. The most important actions of the beta drugs are stimulation of the heart (beta-I) and procrastination (beta-2). Epinephrine is the drug of choice for the immediate reattempt of acute allergic reactions, such as nonphysical The alpha-blockers compete with EN and PEP for binding to the alpha-adrenaline receptors. When the alpha-blocker binds to the receptors, it prevents EN and PEP from producing the alpha sympathetic responses.
The alpha-blockers are used in the treatment of hypertension, especially when excessive vasoconstriction is present. The alpha- blockers are also used in peripheral vascular conditions (poor blood flow to skin and extremities) such as Urinary’s disease, where the vacillation increases blood flow to the skin and extremities. Alpha-blockers are used in the treatment of phosphorescently, a tumor of the adrenal medulla where excessive catecholamine levels cause severe hypertension Beta-blocking drugs bind to beta-adrenaline receptors and antagonize the beta effects of PEP and EN.
Patients with hypertension, angina vectors, and cardiac arrhythmias often have increased sympathetic activity, with excessive amounts of PEP and EN being released. By occupying beta receptors, the beta-blockers antagonize and reduce the effects of PEP and EN on beta receptors. The heart (beta-I) is one of the most important beta organs and the main clinical use f beta-blockers is to decrease the activity of the heart. Blockade of the beta-I receptors produces a decrease in heart rate, force of contraction, and impulse conduction through the conduction system of the heart.
These effects are useful in patients with fast heart rates (tachycardia), cardiac arrhythmias, and other cardiac conditions where excessive sympathetic activity is present. Decreasing cardiac function also decreases blood pressure and beta-blockers are used in the treatment of hypertension The main activity that occurs inside the adrenaline nerve endings is the formation and storage of EN. Morphogenesis is synthesized from amino acids, either phenylalanine or tyrosine. Several drugs interfere with the formation or the storage of EN.
Such drugs are called adrenaline neuronal blockers. Chapter 7 – Drugs affecting Parasympathetic Nervous system The autonomic nervous system regulates the functions of the internal organs and glands. As previously discussed, the sympathetic division controls activity during physical exertion and stress (fight or flight). The parasympathetic division regulates body functions mainly during rest, digestion, and waste elimination. Parasympathetic stimulation increases the activity of the gastrointestinal and genitourinary systems and decreases the activity of the cardiovascular system.
Drugs that increase parasympathetic activity (choleric) are used in the treatment of Listener’s disease, glaucoma, anesthesia graves, and (anticlericalism) are indicated for the treatment of overactive urinary and intestinal conditions, asthma and COOP, motion sickness, and during various ophthalmic procedures. The choleric receptors at the parasympathetic postcolonial nerve endings (as shown in Figure 7. 2(a)) are known as musician receptors.
The term musician is derived from the drug mescaline, which is an alkaloid obtained from a particular type of mushroom. One of the first drugs used to establish the function of the autonomic nervous system (MANS), mescaline produces effects that are similar to those of ACH, but only at these particular receptor sites. Consequently, early pharmacologists referred to these receptors as musician, and the terminology is still in use. Drugs that act like ACH 9293 error mescaline at these receptors are referred to as either choleric or musician.
Drugs that block ACH at the scarring receptors are referred to as interscholastic or antisubmarine The choleric receptors at the neuromuscular Junction (NM]) of skeletal muscle (seen in Figure 7. 2(c)) are known as nicotine-muscle (Nm) receptors. Nicotine also stimulates or acts like ACH at the skeletal neuromuscular Junction. Drugs that block the effects of ACH at the NM] are referred to as neuromuscular blockers or skeletal muscle relaxants The direct-acting choleric drugs primarily increase GIG secretions and motility, increase urinary tract function (urination), and cause papillary constriction (meiosis).
Choleric drugs are used locally during ophthalmic examinations as mitotic to constrict the pupils and in the treatment of glaucoma reversible interrelatedness drugs are more widely used than the direct-acting choleric drugs. They are used in the treatment of glaucoma, anesthesia graves, urinary retention, intestinal paralysis, Listener’s disease and as antidotes to the curare-type skeletal muscle blockers and the interscholastic drugs.
Anesthesia graves is a disease of the skeletal muscle undulate where ACH functions to stimulate muscle tone and contraction Chapter 8 – Drugs affecting Autonomic Ganglia anionic blocker: drug that blocks the nicotine-neural (An) receptors and reduces the activity of the autonomic nervous system. Ganglion stimulant: drug that stimulates the nicotine-neural (An) receptors to increase autonomic nervous system activity. Nicotine: alkaloid drug in tobacco that stimulates Ganglion receptors. Isotonic-neural (An) receptor: choleric receptor at the autonomic ganglia. Ganglion stimulants – use to stop smoking Ganglion blockers bind to and block An receptors. Since the sympathetic division has greater control over regulation of blood pressure, the Ganglion blockers cause a deduction in blood pressure and are primarily used in the treatment of severe hypertension Chapter 9 – Skeletal muscle relaxants Many drugs inhibit skeletal muscle contraction by interfering with neuromuscular function.
Drugs that inhibit skeletal muscle contraction by blocking conduction within the spinal cord are known as centrally acting skeletal muscle relaxants. In contrast, peripheral skeletal muscle relaxants inhibit muscle contraction at the NJ Skeletal muscle relaxation is desirable in spastic diseases (multiple sclerosis and cerebral palsy), conditions in which the spinal cord has been damaged (trauma, paraplegia), ND injuries in which pain accompanies overexertion of the muscles.
In addition, surgical and orthopedic procedures and intubations (for example, bronchus’s) are neuromuscular blockers are used primarily before (premeditation) and during surgical procedures (surgical relaxation) to relax abdominal or antidemocratic skeletal muscles Neuromuscular blockers are used in an ICC setting with critically ill patients who are compromised by their existing conditions of bronchiole’s or chronic obstructive pulmonary disease (COOP), making it difficult for them to be properly externally ventilated.