basic definitions of medical terms

8/14/2019 Basic Definitions of Medical Terms

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Basic Definitions ofBasic Definitions ofMedical TermsMedical Terms

Presented byPresented byMuhammad Ali HaiderMuhammad Ali Haider

B,Pharmacy and MBA (Marketing)B,Pharmacy and MBA (Marketing)


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Infection The growth of a parasitic organism withinthe body. (A parasitic organism is one thatlives on or in another organism and drawsits nourishment therefrom.) A person withan infection has another organism (a"germ") growing within him, drawing its

nourishment from the person.


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Infection (Exception) The term "infection" has some

exceptions. For example, the normal

growth of the usual bacterial flora inthe intestinal tract is not usuallyconsidered an infection. The same

consideration applies to the bacteriathat normally inhabit the mouth.


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Dose and dosage Definition of Dose (dos) the quantity to be administered

at one time, as a specified amount ofmedication or a given quantity ofradiation.


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Types of doses effective dose (ED) that quantity of adrug that will produce the effects forwhich it is given.

lethal dose that quantity of an agent thatwill or may be sufficient to cause death.

maximum dose the largest dose

consistent with safety.


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Types of doses median effective dose (ED50) a dose that produces thedesired effect in 50 per cent of a population.

threshold dose the minimum dose of ionizing radiation, achemical, or a drug that will produce a detectable degree ofany given effect.

tolerance dose the largest quantity of an agent that maybe administered without harm.

loading dose the initial large dose of a drug given to bring tissue and

fluid levels to an effective concentration quickly.


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Adverse Effects In medicine, an adverse effect is a

harmful and undesired effect resulting

from a medication or other interventionsuch as chemotherapy or surgery.

Using a drug or other medical interventionwhich is contraindicated may increase the

risk of adverse effects
http://en.wikipedia.org/wiki/Medicinehttp://en.wikipedia.org/wiki/Chemotherapyhttp://en.wikipedia.org/wiki/Surgeryhttp://en.wikipedia.org/wiki/Contraindicationhttp://en.wikipedia.org/wiki/Riskhttp://en.wikipedia.org/wiki/Riskhttp://en.wikipedia.org/wiki/Contraindicationhttp://en.wikipedia.org/wiki/Surgeryhttp://en.wikipedia.org/wiki/Chemotherapyhttp://en.wikipedia.org/wiki/Medicine


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Out Come of Adverse

Effects The harmful outcome is usually indicated by someresult such as morbidity, mortality, alteration inbody weight, levels of enzymes, loss of function,or as a pathological change detected at themicroscopic, macroscopic or physiological level. Itmay also be indicated by symptoms reported by apatient. Adverse effects may cause a reversibleor irreversible change, including an increase ordecrease in the susceptibility of the individual to

other chemicals, foods, or procedures (e.g.drug interaction).

i
http://en.wikipedia.org/wiki/Morbidityhttp://en.wikipedia.org/wiki/Deathhttp://en.wikipedia.org/wiki/Body_weighthttp://en.wikipedia.org/wiki/Enzymehttp://en.wikipedia.org/wiki/Pathologyhttp://en.wikipedia.org/wiki/Foodhttp://en.wikipedia.org/wiki/Drug_interactionhttp://en.wikipedia.org/wiki/Drug_interactionhttp://en.wikipedia.org/wiki/Foodhttp://en.wikipedia.org/wiki/Pathologyhttp://en.wikipedia.org/wiki/Enzymehttp://en.wikipedia.org/wiki/Body_weighthttp://en.wikipedia.org/wiki/Deathhttp://en.wikipedia.org/wiki/Morbidity


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i erence etweenAdverse effects and

serious adverse effects In clinical trials, a distinction is madebetween Adverse Events (AEs) and SeriousAdverse Events (SAEs). Generally, any

event which causes death, permanentdamage, birth defects, or requireshospitalization is considered an SAE. [1]The results of these trials are oftenincluded in the labeling of the medication

to provide information both for patientsand the prescribing physicians.
http://en.wikipedia.org/wiki/Adverse_effect_(medicine)http://en.wikipedia.org/wiki/Adverse_effect_(medicine)


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How can we avoid

Adverse effects Adverse effects, like intendedeffects of drugs, are a function ofdosage or drug levels at the targetorgans, so they may be avoided ordecreased by means of careful andprecise pharmacokinetics (the change

of drug levels in the organism infunction of time after administration
http://en.wikipedia.org/wiki/Effective_dosehttp://en.wikipedia.org/wiki/Pharmacokineticshttp://en.wikipedia.org/wiki/Pharmacokineticshttp://en.wikipedia.org/wiki/Effective_dose


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Another cause of

adverse effects Adverse effects may also be caused bydrug interaction, i.e., when physicians fail tocheck for all medicaments a patient is taking andprescribe new ones which interact agonistically or

antagonistically (potentiate or decrease theintended therapeutic effect). Significantmorbidity and mortality is caused around theworld because of this. Drug-drug and food-druginteractions may occur, and even so-called

"natural drugs" used in alternative medicine mayhave dangerous adverse effects.
http://en.wikipedia.org/wiki/Drug_interactionhttp://en.wikipedia.org/wiki/Morbidityhttp://en.wikipedia.org/wiki/Alternative_medicinehttp://en.wikipedia.org/wiki/Alternative_medicinehttp://en.wikipedia.org/wiki/Morbidityhttp://en.wikipedia.org/wiki/Drug_interaction


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Side effects Most drugs have a large list of non-severeor mild adverse effects which do not ruleout the interruption of usage. Theseeffects have widely variable incidence,according to individual sensitivity. Theycomprise nausea, dizziness, diarrhea,

malaise, vomit, headache, dermatitis, drymouth, etc.
http://en.wikipedia.org/wiki/Nauseahttp://en.wikipedia.org/wiki/Dizzinesshttp://en.wikipedia.org/wiki/Diarrheahttp://en.wikipedia.org/wiki/Malaisehttp://en.wikipedia.org/wiki/Vomithttp://en.wikipedia.org/wiki/Headachehttp://en.wikipedia.org/wiki/Dermatitishttp://en.wikipedia.org/wiki/Dermatitishttp://en.wikipedia.org/wiki/Headachehttp://en.wikipedia.org/wiki/Vomithttp://en.wikipedia.org/wiki/Malaisehttp://en.wikipedia.org/wiki/Diarrheahttp://en.wikipedia.org/wiki/Dizzinesshttp://en.wikipedia.org/wiki/Nausea


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Examples of Adverse

effects Examples of adverse effects associated with specific medications Abortion, miscarriage or uterinehemorrhage associated with misoprostol (

Cytotec), a labor-inducing drug (this is a case where the adverse effecthas been used legally and illegally for performing abortions)

Addiction to many sedatives and analgesics such as diazepam, morphine,

etc. Birth defects associated with Thalidomide and Accutane.

Bleeding of the intestine associated with aspirin therapy

Cardiovascular disease associated with COX-2 inhibitors (i.e. Vioxx)

Deafness and kidney failure associated with gentamicin (an antibiotic)

Death, following sedation in children using propofol (Diprivan)

Dementia associated with heart bypass surgery
http://en.wikipedia.org/wiki/Abortionhttp://en.wikipedia.org/wiki/Miscarriagehttp://en.wikipedia.org/wiki/Uterinehttp://en.wikipedia.org/wiki/Hemorrhagehttp://en.wikipedia.org/wiki/Misoprostolhttp://en.wikipedia.org/wiki/Cytotechttp://en.wikipedia.org/wiki/Addictionhttp://en.wikipedia.org/wiki/Sedativeshttp://en.wikipedia.org/wiki/Analgesicshttp://en.wikipedia.org/wiki/Diazepamhttp://en.wikipedia.org/wiki/Morphinehttp://en.wikipedia.org/wiki/Birth_defectshttp://en.wikipedia.org/wiki/Thalidomidehttp://en.wikipedia.org/wiki/Accutanehttp://en.wikipedia.org/wiki/Bleedinghttp://en.wikipedia.org/wiki/Intestinehttp://en.wikipedia.org/wiki/Aspirinhttp://en.wikipedia.org/wiki/Cardiovascularhttp://en.wikipedia.org/wiki/Deafnesshttp://en.wikipedia.org/wiki/Kidney_failurehttp://en.wikipedia.org/wiki/Gentamicinhttp://en.wikipedia.org/wiki/Antibiotichttp://en.wikipedia.org/wiki/Deathhttp://en.wikipedia.org/wiki/Sedationhttp://en.wikipedia.org/wiki/Propofolhttp://en.wikipedia.org/wiki/Diprivanhttp://en.wikipedia.org/wiki/Dementiahttp://en.wikipedia.org/wiki/Heart_bypass_surgeryhttp://en.wikipedia.org/wiki/Heart_bypass_surgeryhttp://en.wikipedia.org/wiki/Dementiahttp://en.wikipedia.org/wiki/Diprivanhttp://en.wikipedia.org/wiki/Propofolhttp://en.wikipedia.org/wiki/Sedationhttp://en.wikipedia.org/wiki/Deathhttp://en.wikipedia.org/wiki/Antibiotichttp://en.wikipedia.org/wiki/Gentamicinhttp://en.wikipedia.org/wiki/Kidney_failurehttp://en.wikipedia.org/wiki/Deafnesshttp://en.wikipedia.org/wiki/Cardiovascularhttp://en.wikipedia.org/wiki/Aspirinhttp://en.wikipedia.org/wiki/Intestinehttp://en.wikipedia.org/wiki/Bleedinghttp://en.wikipedia.org/wiki/Accutanehttp://en.wikipedia.org/wiki/Thalidomidehttp://en.wikipedia.org/wiki/Birth_defectshttp://en.wikipedia.org/wiki/Morphinehttp://en.wikipedia.org/wiki/Diazepamhttp://en.wikipedia.org/wiki/Analgesicshttp://en.wikipedia.org/wiki/Sedativeshttp://en.wikipedia.org/wiki/Addictionhttp://en.wikipedia.org/wiki/Cytotechttp://en.wikipedia.org/wiki/Misoprostolhttp://en.wikipedia.org/wiki/Hemorrhagehttp://en.wikipedia.org/wiki/Uterinehttp://en.wikipedia.org/wiki/Miscarriagehttp://en.wikipedia.org/wiki/Abortion


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Examples of Adverse

effects Depression or hepatic injury caused by interferon Diabetes caused by atypical antipsychotic medications (neuroleptic

psychiatric drugs)

Diarrhea caused by the use of orlistat (Xenical)

Erectile dysfunction associated with many drugs, such asantidepressants

Fever associated with vaccination (in the past, imperfectlymanufactured vaccines, such as BCG and poliomyelitis, have causedthe very disease they intended to fight).

Glaucoma associated with corticosteroid-based eye drops

Hair loss and anemia may be caused by chemotherapy againstcancer, leukemia, etc.

Headache following spinal anesthesia
http://en.wikipedia.org/wiki/Depression_(mood)http://en.wikipedia.org/wiki/Cirrhosishttp://en.wikipedia.org/wiki/Interferonhttp://en.wikipedia.org/wiki/Diabeteshttp://en.wikipedia.org/wiki/Atypical_antipsychotichttp://en.wikipedia.org/wiki/Psychiatrichttp://en.wikipedia.org/wiki/Diarrheahttp://en.wikipedia.org/wiki/Orlistathttp://en.wikipedia.org/wiki/Xenicalhttp://en.wikipedia.org/wiki/Erectile_dysfunctionhttp://en.wikipedia.org/wiki/Antidepressanthttp://en.wikipedia.org/wiki/Feverhttp://en.wikipedia.org/wiki/Vaccinationhttp://en.wikipedia.org/wiki/Bacillus_Calmette-Gu%C3%A9rinhttp://en.wikipedia.org/wiki/Poliomyelitishttp://en.wikipedia.org/wiki/Glaucomahttp://en.wikipedia.org/wiki/Corticosteroidhttp://en.wikipedia.org/wiki/Eye_dropshttp://en.wikipedia.org/wiki/Hair_losshttp://en.wikipedia.org/wiki/Anemiahttp://en.wikipedia.org/wiki/Chemotherapyhttp://en.wikipedia.org/wiki/Cancerhttp://en.wikipedia.org/wiki/Leukemiahttp://en.wikipedia.org/wiki/Headachehttp://en.wikipedia.org/wiki/Spinal_anesthesiahttp://en.wikipedia.org/wiki/Spinal_anesthesiahttp://en.wikipedia.org/wiki/Headachehttp://en.wikipedia.org/wiki/Leukemiahttp://en.wikipedia.org/wiki/Cancerhttp://en.wikipedia.org/wiki/Chemotherapyhttp://en.wikipedia.org/wiki/Anemiahttp://en.wikipedia.org/wiki/Hair_losshttp://en.wikipedia.org/wiki/Eye_dropshttp://en.wikipedia.org/wiki/Corticosteroidhttp://en.wikipedia.org/wiki/Glaucomahttp://en.wikipedia.org/wiki/Poliomyelitishttp://en.wikipedia.org/wiki/Bacillus_Calmette-Gu%C3%A9rinhttp://en.wikipedia.org/wiki/Vaccinationhttp://en.wikipedia.org/wiki/Feverhttp://en.wikipedia.org/wiki/Antidepressanthttp://en.wikipedia.org/wiki/Erectile_dysfunctionhttp://en.wikipedia.org/wiki/Xenicalhttp://en.wikipedia.org/wiki/Orlistathttp://en.wikipedia.org/wiki/Diarrheahttp://en.wikipedia.org/wiki/Psychiatrichttp://en.wikipedia.org/wiki/Atypical_antipsychotichttp://en.wikipedia.org/wiki/Diabeteshttp://en.wikipedia.org/wiki/Interferonhttp://en.wikipedia.org/wiki/Cirrhosishttp://en.wikipedia.org/wiki/Depression_(mood)


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Examples of adverse

effects Liver damage from paracetamol Seizures caused by withdrawal from

benzodiazepine

Drowsiness or increase in appetite due toantihistamine use. Some antihistamines are usedin sleep aids explicitly because they causedrowsiness.

Stroke or heart attack associated with sildenafil

(Viagra) when used with nitroglycerine Suicide, increased tendency associated to the use

of fluoxetine and other SSRI antidepressants
http://en.wikipedia.org/wiki/Liverhttp://en.wikipedia.org/wiki/Paracetamolhttp://en.wikipedia.org/wiki/Seizurehttp://en.wikipedia.org/wiki/Benzodiazepinehttp://en.wikipedia.org/wiki/Drowsinesshttp://en.wikipedia.org/wiki/Appetitehttp://en.wikipedia.org/wiki/Antihistaminehttp://en.wikipedia.org/wiki/Strokehttp://en.wikipedia.org/wiki/Myocardial_infarctionhttp://en.wikipedia.org/wiki/Sildenafilhttp://en.wikipedia.org/wiki/Viagrahttp://en.wikipedia.org/wiki/Nitroglycerinehttp://en.wikipedia.org/wiki/Suicidehttp://en.wikipedia.org/wiki/Fluoxetinehttp://en.wikipedia.org/wiki/SSRIhttp://en.wikipedia.org/wiki/SSRIhttp://en.wikipedia.org/wiki/Fluoxetinehttp://en.wikipedia.org/wiki/Suicidehttp://en.wikipedia.org/wiki/Nitroglycerinehttp://en.wikipedia.org/wiki/Viagrahttp://en.wikipedia.org/wiki/Sildenafilhttp://en.wikipedia.org/wiki/Myocardial_infarctionhttp://en.wikipedia.org/wiki/Strokehttp://en.wikipedia.org/wiki/Antihistaminehttp://en.wikipedia.org/wiki/Appetitehttp://en.wikipedia.org/wiki/Drowsinesshttp://en.wikipedia.org/wiki/Benzodiazepinehttp://en.wikipedia.org/wiki/Seizurehttp://en.wikipedia.org/wiki/Paracetamolhttp://en.wikipedia.org/wiki/Liver


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Indication A valid reason to use a certain test,

medication, procedure, or surgery.


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Contraindication In medicine, a contraindication

(pronounced as contra-indication) is a

condition or factor that increasesthe risks involved in using a

particular drug, carrying out a

medical procedure, or engaging in aparticular activity.
http://en.wikipedia.org/wiki/Medicinehttp://en.wikipedia.org/wiki/Riskshttp://en.wikipedia.org/wiki/Medicationhttp://en.wikipedia.org/wiki/Medicationhttp://en.wikipedia.org/wiki/Riskshttp://en.wikipedia.org/wiki/Medicine


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Example of

contraindication Some contraindications are absolute,meaning that there are no reasonablecircumstances for undertaking a course of

action. For example, a baby with a fevershould never be given aspirin because ofthe risk of Reye's syndrome, and a personwith an anaphylacticfood allergy shouldnever eat that food. Similarly, a personwith Hemochromatosis should not beadministered iron preparations.
http://en.wikipedia.org/wiki/Aspirinhttp://en.wikipedia.org/wiki/Reye%27s_syndromehttp://en.wikipedia.org/wiki/Anaphylaxishttp://en.wikipedia.org/wiki/Food_allergyhttp://en.wikipedia.org/wiki/Hemochromatosishttp://en.wikipedia.org/wiki/Hemochromatosishttp://en.wikipedia.org/wiki/Food_allergyhttp://en.wikipedia.org/wiki/Anaphylaxishttp://en.wikipedia.org/wiki/Reye%27s_syndromehttp://en.wikipedia.org/wiki/Aspirin


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Relative Contraindication Other contraindications are relative,meaning that the patient is at higher riskof complications, but that these risks may

be outweighed by other considerations ormitigated by other measures. For example,a pregnant woman should normally avoidgetting X-rays, but the risk may be farless than the risk of not diagnosing or

being able to treat a serious condition suchas tuberculosis or a broken bone.
http://en.wikipedia.org/wiki/X-rayhttp://en.wikipedia.org/wiki/X-ray


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Half Life Biological half-life, pertaining to

organisms (also refers to "elimination

half-life", a pharmacokineticparameter in medicine)
http://en.wikipedia.org/wiki/Biological_half-lifehttp://en.wikipedia.org/wiki/Biological_half-life


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Bioavailability In pharmacology, bioavailability is used to describe thefraction of an administered dose of unchanged drug thatreaches the systemic circulation, one of the principalpharmacokinetic properties of drugs. By definition, when a

medication is administered intravenously, its bioavailabilityis 100%. However, when a medication is administered viaother routes (such as orally), its bioavailability decreases(due to incomplete absorption and first-pass metabolism).Bioavailability is one of the essential tools inpharmacokinetics, as bioavailability must be considered

when calculating dosages for non-intravenous routes ofadministration.
http://en.wikipedia.org/wiki/Pharmacologyhttp://en.wikipedia.org/wiki/Dosehttp://en.wikipedia.org/wiki/Systemic_circulationhttp://en.wikipedia.org/wiki/Pharmacokineticshttp://en.wikipedia.org/wiki/Medicationhttp://en.wikipedia.org/wiki/Intravenoushttp://en.wikipedia.org/wiki/Route_of_administrationhttp://en.wikipedia.org/wiki/First-pass_metabolismhttp://en.wikipedia.org/wiki/First-pass_metabolismhttp://en.wikipedia.org/wiki/Route_of_administrationhttp://en.wikipedia.org/wiki/Intravenoushttp://en.wikipedia.org/wiki/Medicationhttp://en.wikipedia.org/wiki/Pharmacokineticshttp://en.wikipedia.org/wiki/Systemic_circulationhttp://en.wikipedia.org/wiki/Dosehttp://en.wikipedia.org/wiki/Pharmacology


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Definition of

Bioavailability Definition Bioavailability is a measurement of

the extent of a therapeuticallyactive drug that reaches thesystemic circulation and is available

at the site of action.[1]
http://en.wikipedia.org/wiki/Bioavailabilityhttp://en.wikipedia.org/wiki/Bioavailability


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Absolute Bioavailability Absolute bioavailability compares the bioavailability(estimated as area under the curve, or AUC) of the activedrug in systemic circulation following non-intravenousadministration (i.e., after oral, rectal, transdermal,subcutaneous administration), with the bioavailability of thesame drug following intravenous administration. It is thefraction of the drug absorbed through non-intravenousadministration compared with the corresponding intravenousadministration of the same drug. The comparison must bedose normalized if different doses are used; consequently,each AUC is corrected by dividing the corresponding dose

administered.
http://en.wikipedia.org/wiki/Intravenoushttp://en.wikipedia.org/wiki/Route_of_administrationhttp://en.wikipedia.org/wiki/Route_of_administrationhttp://en.wikipedia.org/wiki/Intravenous


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Absolute Bioavailability In order to determine absolute bioavailability of a drug, apharmacokinetic study must be done to obtain a plasma drugconcentration vs timeplot for the drug after bothintravenous (IV) and non-intravenous administration. Theabsolute bioavailability is the dose-corrected

area under curve (AUC) non-intravenous divided by AUCintravenous.

Therefore, a drug given by the intravenous route will havean absolute bioavailability of 1 (F=1) while drugs given byother routes usually have an absolute bioavailability of lessthan one.
http://en.wikipedia.org/wiki/Pharmacokinetichttp://en.wikipedia.org/wiki/Area_under_curvehttp://en.wikipedia.org/wiki/Area_under_curvehttp://en.wikipedia.org/wiki/Pharmacokinetic


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Relative bioavailability This measures the bioavailability

(estimated as area under the curve, or

AUC) of a certain drug when comparedwith another formulation of the samedrug, usually an established standard, orthrough administration via a differentroute. When the standard consists of

intravenously administered drug, this isknown as absolute bioavailability.


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Factors affecting

bioavailability Physical properties of the drug (hydrophobicity, pKa,solubility)

The drug formulation (immediate release, excipients used,manufacturing methods, modified release - delayed release,extended release, sustained release, etc.)

If the drug is administered in a fed or fasted state Gastric emptying rate Circadian differences Enzyme induction/inhibition by other drugs/foods:

Interactions with other drugs (e.g. antacids, alcohol, nicotine)

Interactions with other foods (e.g. grapefruit juice, pomello,cranberry juice)


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Factors affecting

bioavailability Transporters: Substrate of an efflux transporter? (e.g. P-glycoprotein)

Health of the GI tract Enzyme induction/inhibition by other drugs/foods:

Enzyme induction (increase rate of metabolism). e.g. Phenytoin

(antiepileptic) induces CYP1A2, CYP2C9, CYP2C19 and CYP3A4 Enzyme inhibition (decrease rate of metabolism). e.g. grapefruit juiceinhibits CYP3A --> higher nifedipine concentrations

Individual Variation in Metabolic Differences Age: In general, drugs metabolized more slowly in fetal, neonatal, and

geriatric populations Phenotypic differences, enterohepatic circulation, diet, gender.

Disease state e.g. hepatic insufficiency, poor renal function


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Factors affecting

bioavailability Each of these factors may vary from patient topatient (inter-individual variation), and indeed inthe same patient over time (intra-individualvariation). Whether a drug is taken with or

without food will affect absorption, other drugstaken concurrently may alter absorption andfirst-pass metabolism, intestinal motility altersthe dissolution of the drug and may affect thedegree of chemical degradation of the drug byintestinal microflora. Disease states affectingliver metabolism or gastrointestinal function willalso have an effect.


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Relative Bioavailability Relative bioavailability is extremelysensitive to drug formulation. Relativebioavailability is one of the measures usedto assess bioequivalence between two drugproducts, as it is the Test/Reference ratioof AUC. The maximum concentration of

drug in plasma or serum (Cmax) is alsousually used to assess bioequivalence.
http://en.wikipedia.org/wiki/Bioequivalencehttp://en.wikipedia.org/wiki/Bioequivalence

basic definitions of medical terms

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