P-drug/ P-medicine/ Rational Therapeutics

1. Selecting medicines:
The “P-medicine” concept
DR SAHIL KUMAR
DEPARTMENT OF PHARMACOLOGY
MAMC

2. Outline
Rational Prescribing
Concept of p-medicines list
Selecting your set of p-medicines
P-medicine : Example
Advantages of p-medicine
Exercises
Summary

3. “Rational use of medicines requires that
patients receive medications appropriate
to their clinical needs, in doses that meet
their own individual requirements, for
an adequate period of time and at the
lowest costs to the community.”
Rational prescribing

4. Prescription of Rational medicines requires:
Accurate diagnosis.
Selection of best drug from the available.
Prescribing adequate drug for a sufficient length
of time.
Choosing the most suitable drug, weighing of
effectiveness, safety, and availability and cost.
RATIONALIZATION OF PRESCRIPTION
PRACTICES

5. The Concept of p-medicine list
There is a need for evidence based, rational prescription.
Each GP has his/her own context with different needs and
priorities.
Scientists at the University of Groningen suggested a
method where each doctor prepares a list of essential
medicines for different conditions.
P-drug concept has been propagated by the WHO Action
Program on Essential medicines world wide.
Kawakami J, Mimura Y, Adachi I, Takeguchi N. [Application of personal drug (P-drug) seminar to clinical pharmacy
education in the graduate school of pharmaceutical sciences]. Yakugaku Zasshi. 2002 Oct;122(10):819-29/ 20 5

6. PERSONAL
PRACTICAL
PRIORITY
PREFERRED

7. Selecting your set of p-medicines
…

8. -- ah – the first one!

9. PROBLEM
1. Determine the first choice
Give information/advice
Treat without drugs
Treat with a drug – P drug
Refer for Rx
Combinations
2. Check suitability for patient
Define the patient’s problem
Write a prescription
Give info, instructions & warning
MONITOR THE TREATMENT
START THE TREATMENT
CHOOSE THE TREATMENT
DEFINE THERAPEUTIC
OBJECTIVE
Monitor ( & stop ? )
treatment

10. Step 1: Define the patient’s problem
Step 2: Specify the therapeutic objective
Step 3: Verify the suitability of your P-treatment
Step 4: Start the treatment
Step 5: Give information, instructions and warnings
Step 6: Monitor (and stop?) treatment
Selecting a p-treatment:
Overview

12. Step i : Define the diagnosis
Step ii : Specify the therapeutic objective
Step iii : Make an inventory of effective groups of
medicines
Step iv : Choose an effective group (p-group)
Step v : Choose a P-medicine
Selecting a P-medicine: Overview

13. What would be your criteria to select a medicine
Efficacy
Safety
Suitability
Cost
Step iv: Choose an effective group according
to criteria

14. EFFICACY:
Choose the appropriate class of drugs.
Choose the appropriate drug from the above class.
SAFETY
Lower the adverse effects, safer is the drug.
Drugs with higher Therapeutic index are easier and
safer to use.

15. SUITABILITY
Varies from individual to individual.
Depends on:
• Age(pediatric, geriatric)
• Sex, pregnancy
• Co-morbid conditions,hepatic and renal disorders
• Consciousness, bed ridden, vomiting,
• Drug formulation and route of drug administration
(oral drugs being better accepted than injectable)

16. COST COMPARISON
Per tablet , per Unit dose
Cost of one day of treatment
Cost of total cost of treatment
Cost of hospitalization, investigations, injections,
treatment of potential side effects

18. Weight of criteria will differ according
to condition
Efficacy Safety Suitability Cost
B. Meningitis
B. Cystitis
% % % %
% 25 % 25 % 25 % 25General dis.
% 80 % 0% 0% 20
% 30 % 20 % 30 % 20
100
100
100

20. RIGHT THINGS TO DO:
RIGHT PATIENT
RIGHT DRUG
RIGHT DOSE
RIGHT ROUTE
RIGHT FREQUENCY

21. SOURCES OF INFORMATION
PRIMARY LITERATURE
Published articles in journals
SECONDARY LITERATURE
Review articles
Newsletter
Online services eg : Cochrane collaboration
TERTIARY LITERATURE
Published books

22. Example
A 52 year old Taxi driver complains of a sore throat &
cough which started 2 weeks earlier with a cold. He has
stopped sneezing but still has a cough, specially at night.
The patient is a heavy smoker who has often been advised
to stop. Further history and examination reveal nothing
special apart from a throat inflammation. The doctor
again advises the patient to stop smoking and writes a
prescription.
What is your P treatment for the patient?

23. 1. Specify the diagnosis:
Bacterial infection
Irritation of mucus membrane
Tumour in the lung
_________________________________________________
2. Specify your therapeutic objective : suppression of dry
cough

24. Make an inventory of possible treatments :
1. ADVICE
2. NON – MEDICINAL INTERVENTION
3. DRUG – cough suppressants (opioid, anti histaminics )
4. COMBINATIONS
5. REFERRAL

25. TREATMENT EFFICACY SAFETY SUITABILITY COST
Advice
Stop smoking
++++ ++++ - - -
( Unsuitable pt wont )
++++
( cheap )
Non Medicine
Meditation
+ / - +++ + ++++
Medicine group
OPIOID
ANTI HISTAMINE
+++
++
+
+
-
- -
+
+
Medicine
CODEINE
DEXTROMETHORPHAN
CHLORPHENIRAMINE
+++
+++
++
++
+++
-
+
+
+
+ ( 2.3 )
++ ( 1.8 )
+++ (0.7 )

26. Choose a P-medicine
Active substance , dosage form , standard dosage schedule, standard duration
Efficacy Safety Suitability Cost
Medicine 1
Medicine 2
Medicine 3

27. TREATMENT
( 100 )
EFFICACY
( 60 )
SAFETY
( 20 )
SUITABILITY
( 10 )
COST
(10 ) 100
CODEINE 55 12 5 5 77
DEXTROMETHORPHAN 55 15 5 6 81
CHLORPHENIRAMINE 50 14 5 7 75

28. EFFICACY , SAFETY , COST
SUITABILITY FOR THE PATIENT
Rx For A Dry & Tickling Cough After A Cold
A) AVOID SMOKING
B) PRESCRIBE : DEXTROMETHORPHAN SYRUP 5ml ,
4 Times daily for 1 week

30. Advantages of p-medicine
More confidence
More convenient
Less chances of unexpected A/E & interactions
Less complications
Increase adoption of rationale drug use
Health care delivery is easy
Health care management is simple & cheaper

31.  1 )Learn how to handle pharmacological data and concepts
 2 ) New drugs
New diseases
New information
Prescribing medicines dictated to you by others
 3 ) Know alternatives when your “ p medicine” cant be used
P-medicine concept also helps to …

32. Q1. Write a prescription for the
a) acute (mild) treatment and
b) chronic prophylaxis
of Angina Pectoris for a 62 year old man.
P – MEDICINE EXERCISE

33. Acute (mild) Angina : P - Group
DRUGS Efficacy (60) Safety (20) Suitability (20) Total (100)
NITRATES ++ (55) +(12) ++(15) 82
BETA-BLOCKERS +(45) +(12) +(13) 70
CALCIUM
CHANNEL
BLOCKERS
+(35) +(12) +(13) 60
POTASSIUM
CHANNEL
OPENERS
+(30) +(12) +(13) 55
METABOLIC
MODULATORS
+(5) +(12) +(13) 30

34. Acute (mild) Angina : P - Medicine
Drugs Efficacy (55) Safety (20) Suitability
(20)
Cost (5) Total (100)
Glyceryl trinitrate
*Sublingual tab 0.5mg 0.5-30 min (50)
No difference
b/w individual
nitrates (15)
(15) Rs 2.0/ tablet
(5)
85
Isosorbide dinitrate
*Sublingual tab 5mg 2-30 min (45) (15) (15) Rs 2.7/ tablet
(3)
78
Isosorbide mononitrate
*Oral tab 10mg 0.5-4 hours
(40)
(15) (14) Rs 2.4/tablets
(4)
73

35. Prophylaxis of Angina : P -
Group
DRUGS Efficacy (40) Safety (30) Suitability (30) Total
(100)
NITRATES +++(38) +(25) +(15) 78
BETA-BLOCKERS ++(35) ++(28) ++(25) 83
CALCIUM
CHANNEL
BLOCKERS
++(30) +(25) +(20) 75
POTASSIUM
CHANNEL
OPENERS
+(20) +(25) +(15) 60
METABOLIC
MODULATORS
+(20) +(25) +(15) 60

36. Prophylaxis of Angina : P -
Medicine
Drugs Efficacy (30) Safety (25) Suitability (25) Cost (20) Total
(100)
Atenolol
All equally effective
(25)
(20) (20) (5) 70
Metoprolol
(25)
(20) (20) (3) 68
Propranolol
(25)
Contraindicated
in variant
angina (10)
(20)
(4)
59

37. Dr. Shashank Pandey
(MBBS, MD Medicine)
Regn. No. DMC/R/2204
Medicine O.P.D. No. 12,
Vardhaman Hospital, Delhi – 92
Phone : 011-22775035, Email : Shashank.p@gmail.com
Date: 20/02/2018
Name of the patient Satya Sharma
Address 17-D, Pocket – C, Mayur Vihar Phase – 2, Delhi – 110091
Age and Sex 62 years/ Male
Rx
• Tab. GLYCERYL TRINITRATE 5mg SUBLINGUAL STAT
One tablet should be taken.
If symptoms do not resolve, may be repeated at 5 minute intervals for 3 doses.
• Tab. ATENOLOL 25 mg OD
• Follow up in 2 weeks
Signature
(Dr. Shashank Pandey)
Stamp
DISPENSED
Date : 23/03/2016 Pharmacist : Mr. Rajesh
Name of the Pharmacy City : Delhi

38. 2. Write a prescription for chronic prophylaxis
of Angina Pectoris for an asthmatic 62 year old
man.
P – MEDICINE EXERCISE

39. Asthmatic with Chronic Angina
: P - Group
DRUGS Efficacy (40) Safety (30) Suitability (30) Total
(100)
NITRATES +++(38) +(25) +(15) 78
BETA-BLOCKERS ++(35) +(25) (0) 60
CALCIUM
CHANNEL
BLOCKERS
++(33) +(25) +(22) 80
POTASSIUM
CHANNEL
OPENERS
+(20) +(25) +(15) 60
METABOLIC
MODULATORS
+(20) +(25) +(15) 60

40. Asthmatic with Chronic Angina
: P - Medicine
Drugs Efficacy (30) Safety (25) Suitability (25) Cost (20) Total
(100)
Amlodipine (25) (23) (20) (10) 78
Nifedipine (25) (20) (15) (10) 70
Diltiazem (15) (15) (15) (15) 60
Verapamil (20) (10) (15) (15) 60

41. Dr. Shashank Pandey
(MBBS, MD Medicine)
Regn. No. DMC/R/2204
Medicine O.P.D. No. 12,
Vardhaman Hospital, Delhi – 92
Phone : 011-22775035, Email : Shashank.p@gmail.com
Date: 20/02/2018
Name of the patient Satya Sharma
Address 17-D, Pocket – C, Mayur Vihar Phase – 2, Delhi – 110091
Age and Sex 62 years/ Male
Rx
• Tab AMLODIPINE 2.5 mg OD
• Follow up in 2 weeks
Signature
(Dr. Shashank Pandey)
Stamp
DISPENSED
Date : 23/03/2016 Pharmacist : Mr. Rajesh
Name of the Pharmacy City : Delhi

42. I. Rational
therapeutics
II. Selecting your
set of ‘P’ medicine
III. Treating your
patients
SUMMARY

43. SUMMARY
How to select a P- medicine ?
Define the diagnosis
Specify the therapeutic objective
Make an inventory of effective groups
Choose a group according to criteria
Choose a medicine from the chosen groups according to
criteria

44. “There are no prescriptions for life.”
― Marty Rubin