Reasons For Medication Reasons For Medication UseUse
• Diagnose• Treatment• Curative• Lesson pain• Prevent a disease or condition
Where Do Drugs Come Where Do Drugs Come From?From?
• Plants• Animals• Minerals• Laboratory Chemical combinations• Biotechnology Genetics
PharmacokineticsPharmacokinetics
Definition: • The process a drug goes through upon
entering the body• It involves the processes of absorption,
distribution, biotransformation (metabolism - liver), and excretion
PharmacokineticsPharmacokinetics
Absorption: For a drug to work , it must be absorbed. It is absorbed at the site where it is given. Once a drug reaches the capillaries, it is taken into the bloodstream. The rate of absorption varies depending on the type of drug, amount of the drug, route, and the patient.
Pharmacokinetics Pharmacokinetics ContinuedContinued
Distribution: How the drug gets to its target once it is in the bloodstream. Involves circulation of the blood. Targets are cells in tissue or organs.
PharmacokineticsPharmacokinetics
Metabolism: How a drug is broken down for excretion. Products of breakdown are called metabolites. Metabolites are rendered small, inactive or less active before excretion occurs. Metabolism usually occurs in the liver, however can occur in the kidneys, lungs, blood plasma, or intestinal mucosa.
Pharmacokinetics Pharmacokinetics
Excretion: A drug continues to have an action until it is excreted by the body. Kidneys generally are the excretory route. Drugs can be excreted by saliva, sweat, exhalation, breast milk, or feces (poop).
PharmacodynamicsPharmacodynamics
Types of Drug Actions: • Inhibitive or destructive• Protection• Supplementation• Replacement• Physiologic function (increase or
decrease)
PharmacodynamicsPharmacodynamics
Drug Effect or Action Theories:• Agonists- Drug binds to a special receptor
on a target cell and produce the desired effect.
• Antagonists- Drug binds with a special receptor on a target cell and prevent or inhibit a response.
• Non-specific- Neither agonists or antagonists. These drugs gather on a cell’s membrane or go through it and interfere with actual cell function
PharmacodynamicsPharmacodynamics
Timing of Drug Effects: • Onset- time from when a drug is
given to when its effects first occur• Peak Effect- when a drug is at its
maximum effect • Duration- time from when drug
effects begin to when they stop
Routes of Routes of Drug AdministrationDrug Administration
• Buccal(topical)• IM• Inhalation• Intra-articular• Intradermal/dermal• Intrathecal
Topical =‘s any epithelial lined surface. Tongue, rectally, cheek, vagina etc
IV Intracardiac po/PO SC/subq sublingual (topical) topical
Abbreviations for PO or Abbreviations for PO or Topical AdministrationTopical Administration
• Topical• cream• gtts (ear)• ung (ointment)
• PO• cap• gtts (oral/infants) • soln/sol• susp• tab
Frequency of DrugsFrequency of Drugs
• Abbreviations:• bid• h/hr• prn/PRN• q• qd
• qh• q2h• qid• tid• stat
Administration Administration AbbreviationsAbbreviations
• AD (right ear)• AS• AU• OD• OS• OU• os• aa (of each)
• ad (towards)• RX• c (line over it)• dc/DC• KVO/TKO• npo/NPO• per
Nomenclature (Naming) of Nomenclature (Naming) of DrugsDrugs
• Chemical name: chemical make-up of a drug
• Generic name: nonproprietary name given to a drug by the developer of a drug (acetaminophen, ibuprofen, diphenhydramine)
• Trade or Brand name: Proprietary or patented name of the manufacturer of the drug (Tylenol, Motrin & Advil, Benedryl). Manufacturing processes may differ slightly.
Legal ImplicationsLegal Implications(Federal)(Federal)
• Pure Food and Drug Act -Standards for US marketing• Federal Food, Drug, and Cosmetic Act -Regulations -FDA approval• Controlled Substances Act -Established DEA -Schedule of Controlled Substances: C-I - Marijuana C-IV – Phenobarbital (treat
seizures) C-II - Cocaine C-V – antidiarrheal (low abuse
rate) C-III – anabolic steroids The lower the # the higher the addiction/abuse potential
Legal ImplicationsLegal Implications(State)(State)
• Regulate practice acts for ordering, prescribing, and administration of medications
• As a surgical technologist, we act as an extension of the physician handling drugs under their supervision
Legal ImplicationsLegal Implications(Local)(Local)
• May have specific guidelines for medication administration in the institution you are employed in
Metric PrefixesMetric Prefixes
• Micro-one-millionth; 0.000001• Milli-one-thousandth; 0.001• Centi-one-hundredth; 0.01• Deci-one-tenth; 0.1• Unit-one;1.0• Deka-ten;10.0• Hecto-one-hundred;100.0• Kilo-one thousand;1000.0
Metric EquivalentsMetric Equivalents
• Weight (gram)• 1 gram=1000
milligrams• 1 kilogram=1000
grams• 1 ounce=30 grams• Capacity (liter)• 1 liter=1000
milliliters• 1000 liters=1
kiloliter• 1 liter=1.06 quarts
• 1 quart=0.946 liters• 1 milliliter weighs 1
gram• 1 cubic centimeter
(cc) and 1 milliliter (ml) are equal/same
• 1 liter=1000ml or cc• 1 fl. oz.=30ml or cc• 1 fl. dram=0.125fl.
oz. or 4ml or cc• 1 gallon=3.8 liters
Metric EquivalentsMetric Equivalents
• Length (meter)• 1 meter=1000mm=100cm=1.094
yd• 1 yard=3 ft.=36 in.=0.9144 meters• 1 in.=2.54 cm=25.4mm• 1 micron
(micrometer)=0.001mm=0.000001 meter
Metric AbbreviationsMetric Abbreviations
• Gram-gm• Milligram-mg• Kilogram-kg• Liter-L• Milliliter-ml
• Cubic centimeter-cc
• Meter-M• Millimeter-mm• Centimeter-cm
Temperature MeasuringTemperature Measuring
• Fahrenheit (F)Water freezes at 32°Water boils at 212°• Celsius (C) (centigrade)Water freezes at 0°Water boils at 100°
Converting C° to F° or Converting C° to F° or F° to C°F° to C°
• Fahrenheit to Celsius• 5/9 (F°-32) = C° ( or F -32 x 5 divided by 9
= C)
• Celsius to Fahrenheit• 9/5 (C°)+32 = F° (or C x 9 divided by 5 + 32
=‘s F)
Dosage CalculationsDosage Calculations
• Formula:• D (desired dose) x Q (quantity of dose on
hand)
H (dose on hand) =‘s X X = Amount to give/needed• Example: Give 80mg of a drug from
a 30ml stock bottle labeled “100mg per 1ml
• I know: 1ml=100mg Need to give 80mg• I do not know: Fraction of ml
that=80mg• Common sense: If 1 ml of the
solution = 100mg of the drug, then the amount given must be less than 1ml.
• Formula: D x Q = amt to give H• Solution: 80mg x 1ml=0.8 ml of
sol. 100mg• Proof: 80÷100=0.8 0.8x1=0.8
Standard Dilution Standard Dilution EquationsEquations
• C1 x V1 = C2 x V2• C = concentration in %• V = volume• Problem: Dr. needs 60 ml of ½%
contrast media. How much NACL and how much media do you need to make the required amount when you have 60 ml’s of 1% media?
• First we must convert the % to decimals
• 1/2% = 0.5• 1 divided by 2 = 0.5• You always do this when
converting percentages to decimals
• C1=1/2%=0.5 Concentration 1 (asked for)
• C2=1% = Concentration 2 (given)• V1=60ml Volume 1 (asked for)• V2=x (? volume of saline)
• Formula: C1 x V1 = C2 x V2• 0.5 x 60 =1 x x• 30 = x• So, You add x=30 ml’s of pure saline• Need 60mlof 1% – 30ml’s = 30ml’s of
1% dye solution and add 30ml’s saline to get 60ml of 0.5% dye solution
Standard Dilution Standard Dilution EquationEquation
• Doctor wants ½% lidocaine. You have 25ml of 1% Lidocaine. How do you dilute it to the proper strength?
• C1 (asked) x V1 (given) = C2 (given) x V2 (?)
• ½% x 25 = 1% x x• 12.5= x• 25ml lidocaine – 12.5mlof 1% lidocaine =
12.5ml lidocaine = 12.5ml saline = ½% or 0.5% lidocaine
Calculating mg Dose Calculating mg Dose per kg Body Weightper kg Body Weight
• Normal dose of propofol (an induction drug used by anesthesia) is 2 mg per kg for an adult
• Find initial dose for an adult weighing 150lbs
• Convert lbs. to kg (2.2 lbs. = 1kg)• 150lbs. ÷ 2.2lbs. = 68kg• 68kg x 2mg = 136mg
Calculating Child Calculating Child DosagesDosages
• Clark’s Rule: Standard adult weight=150lbs• Problem: If an adult receives 75mg of
Demerol, what would be an appropriate dose for a child weighing 30lbs?
• Adult dose=75mg• Child weighs 30lbs.• Clark’s rule Standard adult weight =
150lbs.• Common sense: child is smaller, dose will
be less than 75mg
• Formula: Child’s weight x Adult dose = Child’s
dose
Adult weight• Solution:• 30lbs. x 75mg = 15mg of Demerol 150lbs
Mixing MedicationsMixing Medications
• Do not mix drugs unless you know for certain that they are compatible together
• If a compatibility is questioned direct the question to the pharmacist to be certain before mixing
• Mixing drugs that are incompatible can result in decreased or increased efficacy, precipitates/crystallization of the drugs which could cause embolization of the drug in the patient, or death
• Institutional pharmacies keep a compatibility chart in the pharmacy/Some ORs may have them in the room
Top Related