INTRODUCTION TO INTRODUCTION TO PHARMACOLOGYPHARMACOLOGY

Pharmacology IntroductionPharmacology IntroductionOutcomesOutcomes

Briefly discuss professional principles relevant to drug Briefly discuss professional principles relevant to drug administrationadministration

Briefly discuss ethical principles applied to drug Briefly discuss ethical principles applied to drug administrationadministration

Explain the nurses roles in ‘health education’ related Explain the nurses roles in ‘health education’ related to medicationto medication

Define Pharmacology Define Pharmacology Define PharmacotherapueticsDefine Pharmacotherapuetics Define PharmacokineticsDefine Pharmacokinetics Define PharmacodynamicsDefine Pharmacodynamics Define the words drug and medicineDefine the words drug and medicine Outline the history of drug developmentOutline the history of drug development State four sources of drugs, giving one example from State four sources of drugs, giving one example from

each sourceeach source Explain drug names- giving one example from the Explain drug names- giving one example from the

BNFBNF

Pharmacology IntroductionPharmacology IntroductionOutcomesOutcomes

State three different ways in which drugs work State three different ways in which drugs work (pharmacodynamics) giving examples of drugs (pharmacodynamics) giving examples of drugs from each group.from each group.

Briefly explain what is meant by therapeutic rangeBriefly explain what is meant by therapeutic range Briefly explain why side effects may occur in Briefly explain why side effects may occur in

addition to ‘desired’ effectsaddition to ‘desired’ effects Define and outline types of adverse drug reactionsDefine and outline types of adverse drug reactions State the role of the State the role of the MHRA List three types of drug interaction Outline the stages of clinical trials

Case Example 1Case Example 1Lauren (age 21years) was prescribed Clozapine whilst in Lauren (age 21years) was prescribed Clozapine whilst in hospital to treat her schizophrenia. hospital to treat her schizophrenia.

She has been taking this medication for one year now and She has been taking this medication for one year now and her mental health has improved considerably. She has been her mental health has improved considerably. She has been discharged from hospital (under Section 25) and is living in discharged from hospital (under Section 25) and is living in supported accommodation near her mother. supported accommodation near her mother.

Since staring on the medication she has experienced a Since staring on the medication she has experienced a number of side effects. She feels tired much of the time, has number of side effects. She feels tired much of the time, has gained 4 stone in weight, is always constipated and has gained 4 stone in weight, is always constipated and has excessive saliva production (hyper salivation) (she is too excessive saliva production (hyper salivation) (she is too embarrassed to stay overnight at a friend’s home). embarrassed to stay overnight at a friend’s home).

Since she is feeling a lot better mentally, and is getting Since she is feeling a lot better mentally, and is getting really fed up with the side effects of her medication, she really fed up with the side effects of her medication, she decides to stop taking the Clozapine. She intends to discuss decides to stop taking the Clozapine. She intends to discuss this with her CPN when he next visits her (he is off sick at this with her CPN when he next visits her (he is off sick at present and they have been too short staffed to send present and they have been too short staffed to send anyone else!).anyone else!).

Discuss!! Discuss!!

Case example 2Case example 2

Student nurse Helen was on her first clinical placement and Student nurse Helen was on her first clinical placement and had been on the ward for a few days. She was asked by the had been on the ward for a few days. She was asked by the nurse in charge to give a patient (Mr Y) a suppository, as he nurse in charge to give a patient (Mr Y) a suppository, as he was complaining of constipation. She was instructed to use was complaining of constipation. She was instructed to use the ‘PR’ tray from the clinical room. She followed the correct the ‘PR’ tray from the clinical room. She followed the correct procedure (as taught by the clinical teacher) with respect to procedure (as taught by the clinical teacher) with respect to inserting the suppository (e.g. maintaining patient dignity, inserting the suppository (e.g. maintaining patient dignity, ensuring correct patient position and effective ensuring correct patient position and effective communication). The suppository was inserted and the communication). The suppository was inserted and the patient advised to ring for the nurse as soon as he needed patient advised to ring for the nurse as soon as he needed the toilet. the toilet. Half an hour passed and the patient expressed concern that Half an hour passed and the patient expressed concern that the suppository had not worked (at all) and this had never the suppository had not worked (at all) and this had never been the case previously.been the case previously.It transpired that the usual suppository (‘glycerin’) was not It transpired that the usual suppository (‘glycerin’) was not on the PR tray and the student had used one called on the PR tray and the student had used one called ‘aminophylline’. ‘aminophylline’.

Discuss!!Discuss!!

Case example 3Case example 3Mr Edwards (age 67) has had NIDDM for more than Mr Edwards (age 67) has had NIDDM for more than 15 years. Initially, his condition was controlled with 15 years. Initially, his condition was controlled with diet alone but for the last 5 years he has needed diet alone but for the last 5 years he has needed oral hypoglycaemic agents. He attends all his GP oral hypoglycaemic agents. He attends all his GP and diabetic clinic appointments and seems to be and diabetic clinic appointments and seems to be complying with both diet and medication regimes.complying with both diet and medication regimes.He is a keen gardener lost confidence in going to He is a keen gardener lost confidence in going to his garden alone as he has had a number of his garden alone as he has had a number of episodes of nausea, sweating, tremors, dizziness episodes of nausea, sweating, tremors, dizziness and palpitations that occur mostly in the late and palpitations that occur mostly in the late morning. His prescription drugs have not been morning. His prescription drugs have not been changed for a number of years and he is not changed for a number of years and he is not feverish, has no pain, nor is he exhibiting any signs feverish, has no pain, nor is he exhibiting any signs of illness other than these worrying episodes. His of illness other than these worrying episodes. His main concern is that these symptoms will occur main concern is that these symptoms will occur when he is driving.when he is driving.

Discuss!Discuss!

Case Example 4Case Example 4

Mr Edwards (Age 67–man diagnosed with NIDDM) Mr Edwards (Age 67–man diagnosed with NIDDM) also has been medically managed for his also has been medically managed for his hypertension for the last 15 years has hypertension for the last 15 years has hypertension. He was taking an ACE inhibitor to hypertension. He was taking an ACE inhibitor to control his Hypertension was had now been control his Hypertension was had now been prescribed a Diuretic as well. He returned to talk prescribed a Diuretic as well. He returned to talk to the practice nurse to complain that his to the practice nurse to complain that his dizziness had returned, particularly when he dizziness had returned, particularly when he stood up and he had actually stumbled with this a stood up and he had actually stumbled with this a couple of times.couple of times.

The Practice nurse reviewed his Blood pressure The Practice nurse reviewed his Blood pressure (lying and standing) and noticed that at there was (lying and standing) and noticed that at there was a difference.a difference.

Discuss the advice you would offer Mt EdwardsDiscuss the advice you would offer Mt Edwards

Case Example 5Case Example 5

A doctor was deputising for a colleague absent on leave. A doctor was deputising for a colleague absent on leave. After a particularly demanding night, he was asked, in After a particularly demanding night, he was asked, in the early hours of the morning, to see a premature infant the early hours of the morning, to see a premature infant with congestive heart failure. He was not normally with congestive heart failure. He was not normally responsible for the care of premature infants but he responsible for the care of premature infants but he requested Digoxin to be given intramuscularly and requested Digoxin to be given intramuscularly and calculated (by mental arithmetic) that the dose should calculated (by mental arithmetic) that the dose should be 0.6 mg.be 0.6 mg.

Just as he settled down for a restorative nap, the nurse Just as he settled down for a restorative nap, the nurse phoned to ask whether the dose shouldn’t be 0.06 mg as phoned to ask whether the dose shouldn’t be 0.06 mg as she had had to open two ampoules. she had had to open two ampoules.

Without thinking he told her to “give it as I ordered”. An Without thinking he told her to “give it as I ordered”. An hour later, he was called to the ward because the baby hour later, he was called to the ward because the baby had suffered a cardiac arrest.had suffered a cardiac arrest.

Discuss!!Discuss!! http://www.medicalprotection.org/uk/booklets/common-problems-hospital/prescribing-for-children accessed 20/08/2012 accessed 20/08/2012

‘‘Justification for study’Justification for study’The nurse with knowledge and understanding of pharmacology will be more confident in drug administration

Who is responsible for ‘health education’ with respect to medication?

What professional principles are relevant?

What ethical principles can be applied to the issue of patients being educated about their medication?

Some Clinical Practice Some Clinical Practice ConsiderationsConsiderations

The patient may ask:The patient may ask:

How quickly will the drug work? (e.g. analgesic)How quickly will the drug work? (e.g. analgesic)

Do I take the tablets with food or on an empty Do I take the tablets with food or on an empty stomach? (e.g. antibiotics)stomach? (e.g. antibiotics)

Can I take my other tablets (OTC medication) Can I take my other tablets (OTC medication) with the medicine I have been prescribed? (e.g. with the medicine I have been prescribed? (e.g. aspirin)aspirin)

Does it matter if I take the tablets at different Does it matter if I take the tablets at different times? (e.g. antibiotics)times? (e.g. antibiotics)

The nurse needs to be able to give the patient The nurse needs to be able to give the patient accurate information and ‘empower’ the patient accurate information and ‘empower’ the patient to be able to self medicateto be able to self medicate

‘‘Justification’Justification’King RL (2004) Nurses’ perceptions of their pharmacology educational needs Journal of Advanced Nursing45(4), 392–400

Background:Lack of science teaching in nurse educationTheory–practice gap in this area of the curriculum

Findings:Limited understanding of the subjectDissatisfaction with the teaching of pharmacology, Resulting anxiety on qualifying

Conclusion:Nurses have a limited understanding of pharmacology They recognize the need for pharmacology knowledge in practice.

Improved pharmacology teaching might increase nurses’ confidence in: drug administration + patient education, and decrease anxieties related to these roles

‘‘Justification’Justification’

Latter S Rycroft-Malone J Yerrell P Shaw D (2000) Latter S Rycroft-Malone J Yerrell P Shaw D (2000) Evaluating educational preparation for a health Evaluating educational preparation for a health education role in practice: the case of medication education role in practice: the case of medication educationeducation

Current health care policy highlights the importance of Current health care policy highlights the importance of nurses contributing to educating patients about nurses contributing to educating patients about medication.medication.

Findings (of the study) highlighted the importance of:Findings (of the study) highlighted the importance of:* sufficient taught pharmacology* sufficient taught pharmacology* an evidence-based curriculum* an evidence-based curriculum* practice-based learning* practice-based learning

J Adv Nurs. 2000 Nov;32(5):1282-90. 2000 Nov;32(5):1282-90.

The NMC (2008) Medicine Management guidelines The NMC (2008) Medicine Management guidelines directs us all to address our Knowledge and directs us all to address our Knowledge and competence for safe medicines storage and competence for safe medicines storage and administration. administration.

‘‘Justification’Justification’The Impact of Drug Errors The Impact of Drug Errors

Patients, their relatives and Patients, their relatives and professionals can experience professionals can experience considerable trauma and there can considerable trauma and there can be a substantial additional cost to be a substantial additional cost to the NHSthe NHS

(Armitage 2004)(Armitage 2004)

Appropriate (and Inappropriate) use Appropriate (and Inappropriate) use of drugsof drugs

Drugs are used to:Drugs are used to:* Cure or Arrest DISEASE* Cure or Arrest DISEASE

* Relieve SYMPTOMS* Relieve SYMPTOMS

* Obtain a DIAGNOSIS* Obtain a DIAGNOSIS

* PREVENT disease occurring* PREVENT disease occurring

(Some situations when they should NOT (Some situations when they should NOT be used: To make the patient ‘easier to be used: To make the patient ‘easier to manage’!manage’!When they will do more harm than good)When they will do more harm than good)

Nurses need knowledge of Nurses need knowledge of pharmacologypharmacology

Nurses need to:Nurses need to:Obtain drug HISTORIESObtain drug HISTORIES

ASSESS patients taking drugsASSESS patients taking drugs

ADMINISTER drugsADMINISTER drugs

EDUCATE patientsEDUCATE patients

MONITOR, record, evaluate and MONITOR, record, evaluate and

REPORT patient responses to REPORT patient responses to drugsdrugs

AND … counsel patients having drug AND … counsel patients having drug rehabilitationrehabilitation

Science of PharmacologyScience of Pharmacology

PharmacologyScience (logos) of drugs (pharmakon)

PharmacoTHERAPEUTICS = use of drugs to treat disease

Assessment Assessment

ImplementationImplementation

Monitoring and Monitoring and

Reassessment/evaluationReassessment/evaluation

Science of PharmacologyScience of Pharmacology PharmacoKINETICS = Absorption,

distribution, metabolism & excretion of drugs (what the body does to the drug)

PharmacoDYNAMICS = Biochemical & physical effects of drugs; Mechanisms of drug action (what the drug does to the body)

TOXICOLOGY = toxicity & adverse effects of drugs

Drugs and MedicinesDrugs and Medicines

A DRUG is any chemical (except food) that A DRUG is any chemical (except food) that will bring about a response in the bodywill bring about a response in the body

* All drugs are TOXIC (potentially)* All drugs are TOXIC (potentially)

* All drugs produce SIDE EFFECTS* All drugs produce SIDE EFFECTS

* Interactions can occur between drugs (or * Interactions can occur between drugs (or between drugs and food)between drugs and food)

A MEDICINE is a drug that has A MEDICINE is a drug that has

been ‘modified’ so that it is been ‘modified’ so that it is

suitable for administrationsuitable for administration

The (very brief!) History of The (very brief!) History of PharmacologyPharmacology

Oldest Science (originally a brand of magic!) Oldest Science (originally a brand of magic!)

Opium used for thousands of yearsOpium used for thousands of years

Samuel Dale (London) catalogued existing knowledge Samuel Dale (London) catalogued existing knowledge of drugs of drugs Descriptive PharmacopoeiaDescriptive Pharmacopoeia

Early in 19Early in 19thth Century began experiments to establish Century began experiments to establish WHY drugs worked (beginning of real pharmacology)WHY drugs worked (beginning of real pharmacology)

Discoveries of the 19Discoveries of the 19thth Century include: Century include:

1842 ether 1847 chloroform 1842 ether 1847 chloroform

History of PharmacologyHistory of Pharmacology

Some key discoveries of the 20th Some key discoveries of the 20th Century: Century:

1922 Insulin1922 Insulin

1941 Penicillin (first treatment)1941 Penicillin (first treatment)

1952 Chlorpromazine1952 Chlorpromazine

1957 Benzodiazepine 1957 Benzodiazepine derivativesderivatives

1958 Haloperidol1958 Haloperidol

1961-1967 Levodopa1961-1967 Levodopa

Sources of drugs / medicinesSources of drugs / medicines

Plant products or Plants:Plant products or Plants:

Fox GloveFox GloveDIGOXINDIGOXIN

PoppyPoppy OPIUMOPIUM

BelladonnaBelladonna ATROPINEATROPINE

CoffeeCoffee CAFFEINECAFFEINE

TobaccoTobacco NICOTINENICOTINE

Animal productsAnimal products

Premarin (conjugated Premarin (conjugated Oestrogen) from Pregnant Oestrogen) from Pregnant Mares Mares

Insulin from pigs & cowsInsulin from pigs & cows

HeparinHeparin from pigs & cowsfrom pigs & cows

Inorganic compoundsInorganic compounds

(compounds with no Carbon)(compounds with no Carbon)

* Zinc + Sulphate ions* Zinc + Sulphate ions

Zinc Sulphate (Calamine Zinc Sulphate (Calamine lotion)lotion)

* Aluminium +Hydroxyl * Aluminium +Hydroxyl

Aluminium hydroxideAluminium hydroxide

* KCl* KCl

Synthetic sourcesSynthetic sources Drugs made in LABORATORY Drugs made in LABORATORY

Most drugs today made in labs = Most drugs today made in labs = safersafer

Many drugs are synthetic copies of Many drugs are synthetic copies of naturally occurring substances e.g. naturally occurring substances e.g. steroidssteroids

Insulin (biosynthetic human Insulin (biosynthetic human insulin / recombinant or insulin / recombinant or DNA-derived insulin)DNA-derived insulin)

Plasmid from E coli cell Plasmid opened by an enzyme

Human insulin gene inserted

Recombination (new insulin gene + plasmid)

Recombined plasmid put into host E Coli cell

Cell division

cells produce human insulin

Drug NamesDrug NamesChemicalChemical GenericGeneric Brand NameBrand Name

Describes actual Describes actual Official MedicalOfficial Medical Name chosen Name chosen byby

CompoundCompound name for active name for active manufacturermanufacturer

substancesubstance

?? DIAZEPAMDIAZEPAM VALIUMVALIUM

?? SODIUM SODIUM EPILIMEPILIM

VALPROATEVALPROATE

Involves study of the effects of the drug in Involves study of the effects of the drug in the the

body & its mechanisms of actionbody & its mechanisms of action

PharmacodynamicsPharmacodynamics

What Drugs DoWhat Drugs Do

REPLACE natural body substances REPLACE natural body substances E.g. thyroxine, insulinE.g. thyroxine, insulin

Act against ABNORMAL cells or Act against ABNORMAL cells or invading ORGANISMS invading ORGANISMS E.g. chemotherapeutic agents, E.g. chemotherapeutic agents,

antibioticsantibiotics

What Drugs DoWhat Drugs Do

Interfere with cell FUNCTION Interfere with cell FUNCTION Act at RECEPTOR SITES Act at RECEPTOR SITES

intensifying cell activity intensifying cell activity (agonists) or (agonists) or

reducing activity (antagonists)reducing activity (antagonists)Clozapine administration was found to produce Clozapine administration was found to produce

dopamine2 (D-2) and serotonin2 (dopamine2 (D-2) and serotonin2 (5-HT25-HT2) ) receptor blockade’receptor blockade’ Inhibit ENZYMESInhibit ENZYMES

neostigmine inhibits neostigmine inhibits cholinesterasecholinesterase

Therapeutic EffectTherapeutic Effect

DoseDoseTHERAPEUTIC THERAPEUTIC

RANGERANGE

TimeTime

Side EffectsSide Effects A drug, once absorbed to the circulation, A drug, once absorbed to the circulation,

will be distributed throughout the body will be distributed throughout the body affecting other parts affecting other parts SIDE EFFECTS SIDE EFFECTS

ExamplesExamples

DrugDrug Side effectSide effect

Clozapine Clozapine Constipation, Hyper Constipation, Hyper salivation, salivation,

IronIron Constipation, NauseaConstipation, Nausea

CodeineCodeine ConstipationConstipation

MorphineMorphine ConstipationConstipation

Adverse ReactionsAdverse Reactions ‘‘Any response to a drug which is noxious, Any response to a drug which is noxious,

unintended and occurs at doses used in unintended and occurs at doses used in man for prophylaxis, diagnosis or therapy’man for prophylaxis, diagnosis or therapy’

ADVERSEADVERSE REACTION (WHO) REACTION (WHO)Adverse reactions: Adverse reactions:

* may be due to * may be due to ALLERGYALLERGY or or GENETICGENETIC absence absence of specific enzymesof specific enzymes* may be predictable or unpredictable * may be predictable or unpredictable * may be TERATOGENIC (causing * may be TERATOGENIC (causing embryonic embryonic deformities)deformities) * are * are IATROGENICIATROGENIC (caused by practitioners) (caused by practitioners)

The Medicines and Healthcare products Regulatory Agency

(MHRA) The Medicines and Healthcare products Regulatory

Agency (MHRA) is the government agency which is responsible for ensuring that medicines and medical devices work, and are acceptably safe.

• The MHRA website http://mhra.gov.uk

SUSPECTED ADVERSE DRUG REACTIONSIf you are suspicious that an adverse reaction may be related to a drug or combination of drugs please complete this Yellow Card.

PATIENT DETAILS SUSPECTED DRUG(S) SUSPECTED REACTION(S) OUTCOME OTHER DRUGS (including self-medication &

herbal remedies) Additional relevant information

The MHRA REGULATES: REGULATES: EXAMPLES:EXAMPLES:Controlled substancesControlled substances OpiatesOpiates

Generic / Generic / proprietaryproprietary drugs drugs ParacetamolParacetamol

Orphan drugsOrphan drugs Rare diseases/small Rare diseases/small populationspopulations

Over-the-counter (OTC) drugsOver-the-counter (OTC) drugs ParacetamolParacetamol

Prescription Only Medicines (POM)Prescription Only Medicines (POM) WarfarinWarfarin

Nurse Prescriber’s Extended Nurse Prescriber’s Extended Minor ailments, Minor ailments, minorminor FormularyFormulary injuries, health injuries, health promotion promotion

& palliative care& palliative care

Drug InteractionsDrug Interactions

These interactions may be beneficial or These interactions may be beneficial or harmful and include:harmful and include:

Alterations in Alterations in ABSORPTIONABSORPTION

Altered Altered METABOLISMMETABOLISM of other drugs of other drugs

Competition for Competition for RECEPTORSRECEPTORS

Some important interactions:Some important interactions: Oral anticoagulants and aspirinOral anticoagulants and aspirin

Development of new drugsDevelopment of new drugs

Preclinical trialsPreclinical trials

New drugs or treatment approaches : New drugs or treatment approaches : often tested first on animals (or live often tested first on animals (or live human cells in test tubes). human cells in test tubes).

Scientists identify an approach that is Scientists identify an approach that is most likely to succeed, and then most likely to succeed, and then carry out preliminary research into carry out preliminary research into safety and effectiveness.safety and effectiveness.

Phase 1 studies: Early Clinical Phase 1 studies: Early Clinical TrialsTrials

These first trials usually involve a These first trials usually involve a small number of individuals (less small number of individuals (less than 100) who are healthy.than 100) who are healthy.However …However …there are times when the new there are times when the new compound is tested first in people compound is tested first in people who have the condition that the who have the condition that the drug is meant to treatdrug is meant to treat(especially when the drug is meant (especially when the drug is meant to treat a very serious disease and to treat a very serious disease and is likely to have serious side is likely to have serious side effects).effects).

The objective= The objective= to find out if the to find out if the new drug is new drug is safesafe..

Phase 2 Continuing Clinical TrialsPhase 2 Continuing Clinical Trials

If the new compound is considered safe on If the new compound is considered safe on animals, testing is expanded to see if it is animals, testing is expanded to see if it is effective, effective,

Trials include people who Trials include people who

have the disease or have the disease or

Condition against which Condition against which

the researchers think a the researchers think a

new compound will be new compound will be

effective.effective.

Phase 3 studiesPhase 3 studies

A drug is tested in several A drug is tested in several

hundred to several hundred to several

thousand subjects. thousand subjects.

This large-scale testing provides more This large-scale testing provides more information about:information about:

*the drug's effectiveness,*the drug's effectiveness,

*possible side effects, and *possible side effects, and

*safety in a broader range of *safety in a broader range of people. people.

Drug Trials Recall that Six men were treated in intensive

care after experiencing a serious reaction to a drug taken during a clinical drugs trial in north-west London in 2006

The six healthy men, all under 40, had volunteered to take part in a trial of an anti-inflammatory drug, to treat conditions such as rheumatoid arthritis and leukaemia, being tested at an independent research unit based at Northwick Park Hospital.

The six suffered multiple organ failure, and two were said to be critically ill. Another two men, who had been given a dummy version of the drug in the trial, did not fall ill.

The trial was stopped as soon as the men fell ill. http://news.bbc.co.uk/1/hi/england/london/4807042.stm Accessed 20/08/2012

Drug trials also don’t always bring about what they are expected to do – The sceince does not work out: http://www.wired.co.uk/magazine/archive/2012/02/features/trials-and-errors accessed 07/11/2013

‘‘Homework’! – Homework’! –

Check the ingredients of four or five different Check the ingredients of four or five different OTC drugs for comparison and to familiarize OTC drugs for comparison and to familiarize yourself with the difficulty a layperson may yourself with the difficulty a layperson may encounter while trying to find this information. encounter while trying to find this information.

Give rationale for why some drugs need to be Give rationale for why some drugs need to be kept under lock and key on the hospital unit. kept under lock and key on the hospital unit. Discuss this with your mentor.Discuss this with your mentor.

Familiarize yourself with 4 or 5 drugs that are Familiarize yourself with 4 or 5 drugs that are often prescribed & administered in your often prescribed & administered in your placement setting.placement setting.

Outline the role of the nurse in the safe Outline the role of the nurse in the safe administration of these drugs. Discuss this with administration of these drugs. Discuss this with your mentor & your clinical teacher.your mentor & your clinical teacher.