Prescribing in General Practice

Prescribing in 

General Practice 

Department of Public Health and Primary Care 

Outline 

• Prescribing in Ireland 

• How to Write a Prescription – regular and 

controlled drugs 

• Rational Prescribing, Social Prescribing, 

Placebos 

• Patient Adherence 

• The Pharmaceutical Industry 

• Case Studies 

Introduction 

• Aims of Session 

– Learn how to write a prescription 

– Discuss the principles of rational prescribing 

– Learn where to get unbiased information 

– Discuss the concept of patient adherence 

– Discuss the factors that influence prescribing 

– Discuss the relationship between the pharmaceutical 

industry and doctors 

– Review case studies of common prescribing problems 

Introduction 

• Prescribing in Irish Primary Care 

– In what % of consultations is a script issued 

– How many items are there in the average 

prescription 

– For the average elderly patient 

– How many prescriptions per GMS pt / year 

Introduction 

• Prescribing in Irish Primary Care 

– In what % of consultations is a Rx issued 63% 

– How many items are there in the average 

prescription 2 

– For the average elderly patient rept Rx 8.8 

– How many Rx per GMS pt / year 6.7 

Prescribing in Ireland 

• The GMS System 

– Doctor Visit card, GMS card 

– Capitation fee per patient on list 

– Approx 1/3 of population covered 

• Family Drug Refund Scheme (100 euro/ month) 

• Long Term Illness Scheme (eg. Diabetes, 

Epilepsy) 

• Generic / Trade Name 

1

Generic v. Brand Names 

• Generic Prescribing 

– Usually cheaper 

– Less confusion (most of the time) 

– Generic names are international – clear exchange of 

information 

In Ireland, at present: 

– Private patients: pharmacist not obliged to give 

cheapest formulation if GP prescribes generically 

– GMS patients: government and pharmacists have 

agreed prices for various drugs 

– Future changes 

Generic v. Brand Names 

• Brand Name Prescribing 

– Supports research and development by 

pharmaceutical companies 

– Familiarity for patients May prejudice 

adherence 

– Brand names usually shorter, and easier to 

remember 

– Usually more expensive than generic 

– Protected period following drug launch: Patent 

lasts for 10 years (usually) then comes “offlicence” 

Rational Prescribing 

• Aims of Good Prescribing 

– Maximise effectiveness 

– Minimise risk 

– Minimise cost 

– Patient centred 


• What is it 

– Prescribing conforms to consensus opinion of the 

current best practice 

• How to Prescribe Rationally 

– Choice of drug is influenced by several considerations: 

• 1. Is the diagnosis known (HTN v. muscular aching) 

• 2. Is a drug required 

• 3. Will it work 

• 4. Will it harm the patient 

• 5. How much will it cost (see next slide) 

• 6. Have all the alternatives been considered 

• 7. Is the likely benefit : risk ratio acceptable 


• Cost of Medication 

– Antihypertensives: 

• Bendroflumethiazide 2.5mg (100 tabs) - €5 

• Atenolol 50mg (30 tabs) - €4.93 

• Lisinopril 5mg (30 tabs) - €10.31 

• Perindopril 5mg (30 tabs) - €18.46 

• Candesartan 8mg (28 tabs) - €21.56 

– Statin – e.g. pravastatin 

• Lipostat 20mg (28 tabs) - €43.44 

• Pravamel 20mg (30 tabs) - €37.58 

– Nu-Seals Aspirin 75mg (28 tabs) - €2.24 


• The Responsible Prescriber 

– Several duties: 

• To ensure that the diagnosis is correct 

• To make a positive and correct decision that a drug is 

needed, and to know enough about the chosen drug 

• To choose a drug appropriate to the patient’s needs 

• To consult the patient, and to ensure there is 

informed consent 

• To explain the patient’s role and to secure his / her 

cooperation 

• To oversee the course of treatment 

• To terminate it when it is no longer needed 

2


• What do you need before writing a 

prescription 

– Clinical skills 

– Knowledge of therapeutics (sources of 

information) 

– Communication skills (education, adherence) 

Keeping Up To Date 

• Sources of Objective Information on Medications 

– Practice formulary 

– Other formularies – MIMS, BNF 

– Summary of Product Characteristics (www.medicines.ie) 

– Peer-reviewed journals 

– Drugs and Therapeutics Bulletin (NHS) 

– National Medicines Information Centre (NMIC: SJH website) 

– Irish Medicines Board (IMB) (www.imb.ie) 

– Guidelines – e.g. NICE 

How to Write a Prescription 

• Write a prescription for a simple analgesic. 


• Must Contain: 

– Date 

– Doctor’s details (or the institution where s/he works) 

– Patient 

• Name 

• Address 

• Age if


• Abbreviations 

– O.D. Omni die 

– B.D. Bis die 

– T.D.S. Ter die sumendus 

– Q.D.S. Quarter die sumendus 

– P.R.N. Pro re nata 

– Nocte / Mane / Tarde 

– P.O. Per orum 

– P.R. Per rectum 

– I.M. Intramuscular 

– STAT 


• Category II Drugs – Schedule of Controlled Drugs 

– Schedule 1 

• Common illicit substances with no medicinal effects – LSD, cannabis, 

coca leaf. They cannot be generally prescribed. 


• Most opiate analgesics – their use is characterised by the care required to 

achieve a balance between their definite clinical benefits, and their 

potential for abuse. E.g. morphine sulphate, physeptone, heroin, cocaine. 


• Some sedatives e.g. midazolam and temazepam, strong analgesics, 

barbiturates 


• Most other sedatives belonging to the BZ group. Other drugs with a 

reduced content of barbiturates 

– Schedule 5 (minimal potential for abuse) 


• Controlled Drug Prescription 

– Must be handwritten, not typed / computer printed 

– The drug formulation must be specified – tablets, syrup etc 

– Strength and quantity of the medication must be prescribed in 

words and figures 

• E.g: morphine slow release tablets 10 mg (ten milligrams); mitte 60 

(sixty) tablets 

– Cannot be repeated, and must be dispensed within 14 days 

Influences on Prescribing 

• Despite the known tenets of rational prescribing, 

doctors often prescribe without proof of efficacy – 

Why 

– Doctor Reasons 

• True variations in medical opinion (Germany 154,000 Rx for HTN 

per 1M pop; UK much less) 

• The pressure of pharmaceutical advertising 

• Habit, peer group recommendation and ignorance 

• Financial considerations 

– Patient Reasons 

• Patient demands / expectations (usually overestimated – a larger % 

leave with a Rx than expected one. Up to 20% of pts don’t fill Rx) 

• Financial considerations 

• Patient knowledge (armed with reams of info off the Internet) 

• GMS v. private (Ireland) 

Influences on Prescribing 

• Social Reasons 

– To play for time (until true picture becomes clearer or natural 

recovery occurs) 

– To cover uncertainty, rather than admit it 

– Medico-legal worries 

– To keep faith with patients, to justify their efforts, and to 

demonstrate concern 

– To avoid confrontation 

– To end a consultation 

– To keep faith with partners (“Friday afternoon ABx”) 

– Attempt at “placebo prescribing” 

– Many patients are adept at securing social prescriptions – 

bargaining, insistence, flattery, comparison with other doctors 

Placebo Prescribing 

• Placebo Response 

– 30-40% response rate 

– In some studies, certain personality traits (e.g. sociability, 

neuroticism) identify those that respond better 

– In other studies there is no link to personality, and they feel that 

most people can respond given the correct situation 

– Males tend to respond more frequently than females and higher 

SEG’s are especially prone 

– Not entirely a psychological response: physiological changes 

have been observed – lowered blood sugars, lowered BP, 

reduced cholesterol (and CVD mortality in one study!) 

– Their time-response mimics pharmacokinetics of active drugs 

– Up to 40% of patients experience side fx 

4


• Factors Affecting Placebo Response 

– Pain levels – more severe means response more likely 

– Anxiety levels 

– Tablet size, appearance and formulation. Effective placebos are: 

• Either very large or very small 

• Unlike an everyday medication in appearance 

• Capsules / injections rather than tablets 

• Bitter to taste 

• Colour is also important 

– Patient expectation 

– High technology: attendance at OPD, X-rays and especially 

invasive invxns have a therapeutic effect 

– Conviction and charisma of prescriber 


• Effect of Drug Colour on Placebo Response 

– Colour Best Response In 

– Blue / green Creams / ointments 

– Green Anxiety 

– Red Analgesia 

– Red / brown Elixirs 

– Yellow Depression 


• Ethical Problems 

– For: 

• It is effective (does the mechanism matter if the result is satisfactory) 

• It is reassuring and helps morale in chronic / incurable disease 

• It fulfils patient expectations 

• There is no significant toxicity 

• There is evidence of an underlying physical basis (e.g. naloxone has been 

shown to reverse placebo-induced pain relief - endorphin-based mech) 

– Against 

• It is deception and an abuse of a relationship of mutual trust 

• It may generate hurt and ill-feeling if the deception is uncovered 

• It delays true diagnosis 

• It reinforces the sick role 

Self-Medication 

– Conscious effort in last decade to increase range of drugs 

available OTC. Drugs can be reclassified as OTC provided they 

are safe, of low toxicity in OD and used only for “minor” selflimiting 

conditions 

• Advantages 

– Opportunity for pts to take more responsibility for their health 

– Can save cost, inconvenience and time in getting a Rx 

– Can ease pressures on surgery appts 

Self- Medication 

• Disadvantages 

– Increased risk of drug interaction with prescription meds 

– Increased risk of self-medication of side fx 

– Risk of inappropriate self medication 

• Serious illness – may mask / delay presentation 

• Taking the wrong preparation / formulation 

• Taking the wrong dose (or the right dose for too short / long) 

– Risk of generating a “pills for all ills” culture in consumers 

– Less feedback on adverse drug rxns 

– Less chance to offer opportunistic health promotion activities 

Doctors need to always ask patients about their use of OTC and 

alternative medications, and educate patients on their safe use 

Adherence (Compliance) 

• The Problem of Non-Adherence (Concordance) 

– 1/3 of patients take their drugs exactly as prescribed 

– 1/3 take their drugs, but not exactly as prescribed 

– 1/3 do not take their drugs 

– 50% of the time patient adherence is sufficient to gain 

therapeutic benefit…….50% of the time it is not 

• Conscious / unconscious 

• Reflects communication 

• Doctor controls prescribing, but patient controls use 

5

Adherence 

• Factors Affecting Adherence (Patient / Doctor Factors) 

– Understanding of the instructions 

• Age of patient 

• Educational level of patient 

• Complexity of regimen etc. (e.g. COCP, bisphosphonates) 

– Quality of doctor-patient interaction 

– Family and social isolation 

– Beliefs, attitude and personality 

• Health belief model 

• Locus of control 

• Ego strength 

• Drug aversion 

Adherence 

• Factors Affecting Adherence (Illness / Medication 

Factors) 

– Number of medications prescribed concurrently 

– Nature of illness 

• Asymptomatic 

• Psychiatric 

• Chronic 

– Use of medicine for prevention rather than treatment 

– Number of troublesome side fx with the medicine 

– Duration of therapy 

Adherence 

• Ways to Improve Adherence 

– Involve the patients and carers in the management 

– Choose the simplest regime possible 

• E.g. once weekly dosing for bisphosphonates 

– Discuss the rationale fully 

– Simple written instructions 

– Review risk : benefit balance 

– Consider alternatives 

– Use expertise of local pharmacist 

– Monitor treatment 

• Review regularly re side fx etc. and adjust regime accordingly 

Adherence 

• What should patients be told about their medication 

– The name of the medicine 

– What it is for 

– How it works (or is thought to work) 

– Whether it is essential, important, or optional 

– How much to take, how to take, how often to take it and how 

long to take it for 

– What benefits to expect 

– What adverse effects might occur 

• Legal obligation to tell patients about common side fx and those that are 

potentially serious (even if rare) – informed consent 

– What to do if no benefit, or less than expected benefit 

– What to do if adverse effects occur 

Special Circumstances 

• Special considerations are needed when prescribing for 

the following patient groups: 

– The elderly 

– Children 

– Pregnant (or potentially pregnant) women 

– Breast-feeding women 

– Terminal care 

– Co-existing medical conditions e.g. renal / liver failure 

– Particular drug categories e.g. warfarin 

The Pharmaceutical Industry 

• Relationship between the Pharmaceutical Industry 

and doctors has come under increasing scrutiny 

– Irish Medical Council issued guidelines in 2004 

• “Non-promotional educational grants represent the only 

acceptable mechanism of financial support by the 

pharmaceutical and medical manufacturing industries to 

individual doctors” 

– Pros: 

• The industry conducts almost all the research and 

development into new drugs, that goes on in the world 

• Provide information and education to healthcare workers 

• Support the economy 

6

The Pharmaceutical Industry 

• Cons: 

– Doctors prescribing is influenced by their interactions with the industry – 

even down to accepting simple gifts like pens etc (sense of obligation, 

familiarity with drug) 

– Doctors consistently underestimate how much this influence affects them 

personally 

– Patients generally are not aware of the links between doctors and the 

industry. Studies have shown that when they find out, they do not approve 

– Studies conducted by pharmaceutical companies are often only published if 

the results are positive for them 

– Information from reps can be inaccurate – one study found that 11% of 

statements made by reps directly contradicted the known facts about a drug 

(including their own promotional material) 

– The pharmaceutical industry spends billions of euro a year on marketing to 

doctors – because it works 

– Ref: www.nofreelunch.org BMJ 2003;326 31 st May (feature edition) 

Case Studies 

• 2 y.o. girl 

– Fever and refusing all food and drink x 24 hours 

– Severe tonsillitis 

Case Studies 

• 17 y.o. boy 

– Fever and unable to take food and drink x 24 hours 

– Severe tonsillitis 

Case Studies 

• 47 y.o. man 

– BP 168/96 

– What do you want to know 

– Would you treat him 

– What would you use 

Case Studies 

• 79 y.o. lady in nursing home, asked to come and r/v re 

dizziness and recurrent falls 

– Medications 

• Madopar 250 QID (levodopa 200mg + benserazide 50mg) 

• Digoxin 0.125mg BD 

• Allopurinol 200mg BD 

• Frusemide 20mg BD 

• Thioridazine 50mg TID 

• Amitryptilline 75mg nocte 

• Nitrazepam 5mg nocte 

– What might be the indications for these medications 

– What are their common adverse effects 

– Are any of them likely to be contributing to her symptoms 

– How would you alter her medication. 

7

Case Studies 

• 50 y.o. male 

– Presents with acute muscle spasm of back 

– PMHx – mild hypertension, angina, gout 

– Medications 

• Aspirin 75mg OD 

• Centyl K (bendroflumethiazide + K+) 2.5mg OD 

• Allopurinol 300mg OD 

– What would you consider prescribing 

– Would you have any concerns about his current Rx 

Case Studies 

• 15 y.o. girl, unaccompanied 

– Wants to go on the oral contraceptive pill 

– How would you proceed 

– What are the ethical issues raised 

Conclusion 

• Apply clinical and communication skills 

• Apply the principles of rational prescribing 

• Search for objective sources of information on 

medications 

• Take steps to maximise adherence 

• Review and monitor 

8

Prescribing in General Practice

Create successful ePaper yourself

Delete template?

Save as template?