PHARMACOLOGY 

The study of the manner in which the function of living systems is affected by chemical substances 

BIOLOGICS 

Agents naturally produced in animal cells, microorganisms, or the body itself 

 SCHEDULES OF CONTROLLED DRUGS

SCHEDULE I 

• All nonresearch use is foribidden
• Hallucinogens
  • LSD, MDA, STP, DMT, mescaline, peyote, bufoteneine, ibojaine, psilocybin,
• Marijuana, tetrahydrocannabinols 

• Prescriptions must be filled at pharmacy within 24 hours
• Can only be written for up to one month - NO REFILLS
• Narcotics
  • Opium, Opium alkaloids and derivatives
    
• Stimulants
  
  • Cocaine, Amphetamine (and derivatives), Methylphenidate (Ritalin)
• Depressants
  • barbitals,PCP

• Prescriptions must be rewritten after 6 months
• Narcotics (maximum amounts exist)
  • Codeine, dihydrocodeine, opium
• Depressants
  • barbiturates mixed with uncontrolled drugs
• Stimulants
  • Benzphetamine
  • Chlorphentermine
  • Diethylpropion
  • Maxindol

• Prescriptions must be rewritten after 6 months - differs from sched. III in penalties for illegal possession.
• Narcotics
  • Pentazocine
  • Propoxyphene
• Stimulants
  • Phentermine
  • Fenfluramine
• Depressants
  • benzodiazepines

NURSING IMPLICATIONS

Drug Regulation 

• The pt has final control over drug use - gives or withholds consent and determines compliance.
• It is our responsibility as nurses to inform pt of options so they can make an educated decision.
• Nurses must be familiar with regulations affecting drug use

• May be dispensed without prescription unless additional state regulations apply.
• Narcotics - no more than 2.5 mg and no less than 0.025 mg of atropine per dosage unit.
• Codeines and ethylmorphine

FDA PREGNANCY CATEGORIES 

• 5 categories exist which indicate potential of a drug for causing birth defects
• Categories are labeled A, B, C, D, X (in order of increasing risk)

• Adequate studies in pregnant women have not demonstrated risk to the fetus
• Vitamins, Minerals

• Animal studies have not demonstrated a risk to the fetus.
• No adequate studies in pregnant women
• Tylenol, insulin, amoxicillin..

• Animal studies have shown an adverse effect on the fetus
• No adequate studies in humans
• Benefits from use of the drug may outweigh potential risks
• Ofloxacin, Bactrim DC, Diflucan

• Evidence of human fetal risk
• In life threatening cases may be used
• doxycycline

• Studies in animals or humans demonstrated fetal abnormalities or adverse reaction.  
• The risk of use in pregnant women clearly outweighs any possible benefit
• Accutane

LABELING REGULATIONS 

• No false or misleading statements
• Dosage and frequency must be clearly stated
• Name, address, and lot # of manufacturer
• Accurate statement of contents
• Warning if habit forming
• Quantity, kind, and preparation of specific ingredients
• Directions for use and contraindications

NEW DRUG DEVELOPMENT 

• May take 6-12 years for development and testing
• Only 1/5000 compounds emerge as a new product

• Preclinical testing
  • investigation, extensive lab testing
  • may take 1-5 years
• Clinical testing
  • Occurs in 4 phases
  • May take 2-10 years to complete
  • first 3 phases are done before drug is marketed
    

DRUG DEVELOPMENT

PHASE I of CLINICAL TESTING 

• Normal, healthy volunteers
• Takes about 1 year
• Goals: evaluations of drug metabolism & determination of effects on humans

• Volunteers with the disease
• Lasts about 2 years
• Goals:  Therapeutic effects & Dose range

• Random, Single, and Double Blind testing
• Takes about 3 years
• Goals: Safety & Effectiveness

• Postmarketing Surveillance
• Drug released for general use - permitting observation of its effects in a large population
• If FDA discovers serious problems it mandates drug be withdrawn from the market

SIX PRINCIPLES OF DRUG ADMINISTRATION 

• RIGHT DRUG - preparer is one held liable
  
• RIGHT DOSE - nurses are last line in defense against errors
• RIGHT ROUTE
• RIGHT TIME - is pt taking multiple medication? Does pt have full/empty stomach? Can meds be taken concurrently?
• RIGHT PATIENT
• RIGHT DOCUMENTATION

MEDICATION ORDERS 

• Know generic names instead of Trade names
  • generic name will always be uncapitalized, Trade names will be capitalized. 
    
  • Trade names are different in different countries
• Pharmacist may substitute for generic unless DAW (dispense as written) is noted.

WRITING A PRESCRIPTION 

• Should always include the following:
  • PT's name
  • Date
  • Name of drug
  • Dose of drug
  • Route of administration
  • Frequency of administration
  • Duration of the therapy
  • Quantity to be dispensed

Ex. PCN 500mg PO TID x10

'500 milligrams of penicillin by mouth 3 times/day for 10 days'

TYPES OF DRUG ORDERS 

• Standing order with termination
  • PCN 500mg PO QID x 10 days
• Standing order without termination
  • Naprosyn 375mg PO BID
• PRN (as needed)
  • Acetaminophn 500mg PO q 4-6 hrs PRN
• Single-dose orders
  • Diflucan 150 mg PO x1
• Stat order
  • Morphine 10mg SC stat
• Protocol orders
  • Sliding scale insulin

• Provided by the USAN Council (United States Adopted Names)
• Used in all countries by any manufacturers
• NOT capitalized

• Patent name given by manufacturer
• The name under which the drug is marketed
• Trade names are approved by the FDA
• Copyrighted symbol is displayed in upper righthand of the name

• NO differences exist between the two - all equivalent products contain the same dose of the same drug.
• The only difference is in the inert ingredients

DRUG CONSTITUENTS 

MAJOR CATEGORIES OF ACTIVE INGREDIENTS

• Alkaloids
• Glycosides
• Oils
• Gums
• Resins

•  Small, cylindrical gelatin containers, holding a dry powder or liquid medicinal agent.
• Convenient way of administering drugs with unpleasant odor or taste
• Can be used as a delayed-action dosage form

• Dried, powdered drugs compressed into small disks
• May have special coating aloweing the tablet to dissolve slowl; releasing the medicinal agent over a prolonged time.  

• Solid emulsions containing agents for external application

• Concentrate, solid preparations of drugs obtained by dissolving the crude drug in alcohol or water; the solution is then allowed to evaporate
• Sedimen - extract

Flat discs containing a medical agent in a flavored base 

Semisolid preparations of medicinal substances in an oily base; such as lanolin or petroleum 

Ground drugs into a fine powder & used in this form 

Mixture of drugs with a firm base, such as cocoa butter, melting at body temperature 

• Glass containers with powdered or liquid drugs
• Used for drugs given by injection
• Ampules: sealed glass containers with one dose of the drug
• Vials: glass container w/ rubber stopper containing a number of doses of the drug

Palatable preparations of drugs made up with alcohol, sugar, and some aromatic substance 

Mixtures of drugs with soap, oil, water, or alcohol to be used for external application only 

Aqueous preparations that contain suspended matter 

Bulky suspensions, in water, of drugs that are insoluble; they look like milk or cream 

Contain a prepared doseage ready for immediate use 

Preparations of volatile (evaporating into vapor) substances dissolved in alcohol

eg, spirit of peppermint 

Solid, insoluble particles dispensed in a liquid

*all must be shaken before use* 

Contain medicinal agents dissolved in sugar and water solution

*particularly effective for masking taste of drug* 

Diluted alcoholic extracts of drugs

Vary in strength from 10% - 20% 

PROPERTIES OF AN IDEAL DRUG

(ALTHOUGH THERE'S NO SUCH THING...)

• EFFECTIVENESS
  • Must elicit response for which it is given
• SAFETY
  • Cannot produce harmful effects
• SELECTIVITY
  • Elicits only the response for which it is given (no side effects)

FACTORS DETERMINING INTENSITY OF DRUG RESPONSE 

PHARMACODYNAMICS 

FOUR PRIMARY RECEPTOR FAMILIES 

SPECIFICITY 

Property of the receptor that lets it discriminate among similar compounds 

SELECTIVITY 

Effects of the drug; may be nonselective or relatively selective

*Selectivity does not guarantee safety 

AFFINITY 

INTRINSIC ACTIVITY 

The ability of a drug to transduce a drug-receptor binding event into a biologic response

Reflected in the drug's maximal efficacy - largest effect that it can produce

Drugs with high intrinsic activity have maximal efficacy 

AGONIST 

*Mimics to create an action - WILL have intrinsic activity and affinity* 

ANTAGONIST 

*Mimics to block the action - will NOT have intrinsic activity

Can be competitive or noncompetitive 

COMPETITIVE ANTAGONIST 

Binds reversibly to receptors 

NONCOMPETITIVE ANTAGONIST 

Bind irreversibly to receptors so total number of receptors available to agonists is reduced 

REGULATION OF RECEPTOR SENSITIVITY 

POTENCY 

An increased potency allows a therapeutic effect at a lower dose 

Drugs with high affinity are generally considered potent

*unrelated to drug dose* 

EFFICACY 

Magnitude of maximal response that can be produced from a particular drug 

THERAPEUTIC INDEX (TI) 

Used as a measure of a drug's safety

TI = LD₅₀ / TD₅₀

The TI indicates the ratio between the lethal dose and the therapeutic dose

(taken as averages in 50% of the pop.)

Large TI - drug is relatively safe

Small TI - relatively unsafe 

Any unintended and undesired effect occurring at normal dose 

Adverse reactions caused by excessive dosing

An unexpected or exaggerated effect to a typical dose

*resulting from genetic predisposition*