2. PharmacotherapyPharmacotherapy
Principally concerned with the safesafe
and effectiveeffective management of drug
administration.
Implies an understanding of
pharmacokinetics (PK) and
pharmacodynamics (PD) so that individual
dosing guidance, can be provided to
optimize patient response .
3. Pharmacokinetics
What the body does to the drug
– Absorption
– Distribution
– Metabolism
– Elimination
Pharmacodynamics
What the drug does to the body
– Response
– Toxicity
4. PharmacotherapyPharmacotherapy
METABOLISM
ABSORPTION
ELIMINATION
- Site (i.e., GIT, skin, tissue
depot)
- First-pass effect (oral)
- Drug properties (i.e., solubility) -Pathway(s)
-Sites (GIT, liver,
lung)
DISTRIBUTION
SITE(S) FOR
THERAPEUTIC
EFFECT(S)
SITE(S) FOR
TOXIC
EFFECT(S)
Pharmacologic
Activity
Toxic
Activity
Free Drug in Plasma
or Extracellular Fluid
Distribution in
Blood Cells
Bound to
plasma proteins
- Unchanged
drug
- Metabolites
- Sites (Tissues, fat, etc)
- Binding
Excretory
Sites
Urine, Feces, Expired AirActive/inactive metabolites
6. Definition
The rational use of drugs 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 cost to them and their
community.
WHO conference of experts, Nairobi 1985
8. Importance of RDU
An irrational drug use results in the
following:
– Treatment failure
– Rapid development of drug resistance
– Increase of toxicity risk
– Wastage of money
11. Diagnosis: Aspects that lead to
Irrational Drug Use
Inadequate examination of patient
Incomplete communication between patient
and doctor
Lack of documented medical history
Inadequate laboratory resources
12. Prescription: Types of Irrational
Drug Use (1)
Irrational
Drug Use Occurs If a Drug Is Prescribed When:
Underprescribing • Needed medications are not prescribed
• Dosage is inadequate
• Length of treatment is too brief
13. Prescription: Types of Irrational
Drug Use (2)
Irrational
Drug Use
Occurs If a Drug Is
Prescribed When:
Incorrect
prescribing
• Drug given for incorrect diagnosis
• Wrong drug selected for diagnosis
• Prescription prepared improperly
• Adjustments not made for co-existing
medical, genetic, environmental, or other
factors
14. Prescription: Types of Irrational
Drug Use (3)
Irrational
Drug Use Occurs If a Drug Is Prescribed When:
Extravagant
prescribing
• A less expensive drug provides
comparable efficacy and safety
• Symptomatic treatment of mild
conditions diverts funds from treating
serious illness
• Brand-name drug used when less
expensive equivalents are available
15. Prescription: Types of Irrational
Drug Use (4)
Irrational
Drug Use Occurs If a Drug Is Prescribed When:
Overprescribing • Drug is not needed
• Dose is too large
• Treatment period is too long
• Quantity dispensed is too great for
current course of treatment
16. Prescription: Types of Irrational
Drug Use (5)
Irrational
Drug Use Occurs If a Drug Is Prescribed When:
Multiple
prescribing
Two or more medications are used
when fewer would achieve same effect
Several related conditions are treated
when treatment of primary condition
would improve or cure the other
conditions
17. Dispensing: Types of Irrational
Drug Use
Incorrect interpretation of the prescription
Retrieval of wrong ingredients
Inaccurate counting, compounding, or pouring
Inadequate labeling
Unsanitary procedures
Packaging:
– Poor-quality packaging materials
– Odd package size, which may require
repackaging
– Unappealing package
18. Adherence vs Compliance
Adherence: The act or quality of sticking
to something; steady devotion; the act of
adhering
The acceptance of an active role in
ones health care
Compliance: the act of yielding,
conforming,
19. Consequences of Poor Adherence
For the individual:
– Treatment failure: incomplete viral suppression,
continued destruction of the immune system, disease
progression
– Drug resistance: emergency of resistant viral strains
– Limited future treatment options: more complex
treatment, more toxicity, uncertain prognosis
20. SLEPT
IN
AWAY
FROM
HOME
RAN
OUT
OF
PILLS
FELT
ILL
FELT
BETTERPILLS
DO NOT
HELP
FEAR
SIDE
EFFECTS
DID NOT
WANT
OTHERS
TO SEE
FAMILY SAID
NO TO
MEDICATION
FORGOT
/ BUSY
DID NOT
UNDERSTAND
INSTRUCTION
S
MISSED DOSES
TAKING
PILL
HOLIDAYS
UNABLE
to CARE
FOR
SELF
Adherence: Why do Patients Miss Doses?
(Barriers to adherence)
Let’s find together a solution for
your problem
•I am listening
•You can trust me
•I understand
•I suggest…
•What do you think?
•I’ll explain to you how to take these
medicines
21. Other Barriers to adherence
Communication
difficulties
Literacy levels
Inadequate knowledge
of disease
Inadequate understanding
of effectiveness of
medications
Lack of social support
Discomfort with
disclosure status
Difficult life conditions
Alcohol and drug use
Depression and other
psychiatric problems
23. Methods and Challenges of
Measuring Adherence
Self reports
Pill counts
Pharmacy records
Provider estimate
Pill identification test
Biological markers
Electronic devices
Measuring drug levels
24. A multi-disciplinary team work is
required to achieve Rational Drug
Use !!!
Doctor
Pharmacist
Counselor /
Treatment
supporter
Nurse
Community
25. CLASSES of DRUGS
Drugs affecting the Autonomic Nervous System
Drugs affecting the CNS
– Antiparkinson drug
– Anti-anxiety
– Hypnotic drugs
– CNS Stimulants
– Anesthetics
– Antidepressant drugs
– Anti-epilepsy
27. Drugs affecting respiratory system
Diuretic drugs
Gastro-intestinal drugs
Antiemetics
Oral Hypoglycemic drugs and Insulin
Hormones of the Pituitary and thyroid
Steroid hormones
Anti-inflammatory drugs
MMS: Importance of RDU in the context of ART programs NSS: This statement was agreed by the WHO conference of experts in Nairobi in 1985 and is still the accepted definition of Rational Drug Use. It highlights the fact that rational use of medicines has many components, all of which must be in place before we can say that a drug has been rationally used. Rational use of drugs should ensure: correct drug appropriate indication appropriate drug considering efficacy, safety, suitability for the patient, and cost appropriate dosage, administration, duration no contraindications correct dispensing, including appropriate information for patients patient adherence to treatment
Message principal à communiquer dans cette diapositive : importance de l’u tilisation rationnelle des médicaments dans le contexte du TAR Question à discuter : quelle est l'importance d'une utilisation rationnelle des médicaments dans le contexte du TAR ? Instructions à l’attention de l’animateur : Donnez aux participants l'occasion de s'exprimer avant de montrer les réponses, mais limitez la discussion à 5 minutes maximum. L'utilisation inappropriée d’antirétroviraux (ARV) peut rapidement déclencher une certaine résistance virale et provoquer l'échec du traitement, la toxicité des médicaments et le gaspillage des ressources financières. Par conséquent, il est important de respecter des normes acceptables avant d'utiliser un traitement antirétroviral (TAR) pour que les patients puissent en retirer tous les avantages. Développement rapide de la résistance aux médicaments si l'observance thérapeutique est inférieure à 90 % Échec du traitement probable si l'observance thérapeutique est inférieure à 95 % Risque élevé de toxicité Gaspillage de ressources financières
Patient& Community Beliefs and (mis)information available in the Community including cultural values on therapy, patient demands& expectations, Prescriber, Dispenser Lack of drug information, limited experience and skills, fear induced prescribing (uncertain diagnosis) Incorrect generalization from experience, inability to read or interpret prescriptions, inadequately trained dispensers, poor attitude about dispensing and packaging Workplace Lack of equipment, facilities, packaging materials, lab capacity, continuing education, pressure to prescribe and dispense, insufficient staffing, inadequate supervision of practitioners. Drug Supply System: Drug Quality Problems unreliable suppliers Bad forecasting/bad quantifications Bad Inventory Management (expired drugs, Shortages, etc.) Pressure and lobbying from Industry (promotional activities and misleading claims) Drug Regulation non-essential drugs available: non-formal prescribers lack of regulation enforcement
MMS: familiarize participants with the components of appropriate drug use IT The purpose of this session is to familiarize participants with the components of appropriate drug use, help them identify common problems in each of these components, and enable them to come up with solutions for such problems. NSS: The drug use process can be qualified as a system that involves steps; from identifying the problem [diagnosis] through prescribing the right medicines suitable for the patient conditions, dispensing and counseling to ensure understanding of how medicines or treatment plan should be followed and adherence on the part of the patient to the treatment plan. Patients may revisit the healthcare facility for follow-up, (especially in chronic disease management, such as treatment of HIV/AIDS) and thus the cycle starts again. **Question to ask to the audience: What problems can occur in prescribing, dispensing, and packaging drugs or in patients’ use of drugs Instructions: Participants should suggest problems that could occur in each step of the process, looking first at Diagnosis – once participants have given their ideas on problems that can occur during diagnosis step then show the suggested answers on the next slide. It is not necessary to go in detail through the points listed on slides 7 – 9 – these are intended as a recap after the participants have discussed to make sure that no important areas are omitted. Once the answers shown for Diagnosis then ask for possible problems with Prescribing, before briefly showing the suggested answers. Repeat the same process for Dispensing and Adherence. Do not forget that dispensing and Adherence will be covered in separate modules so do not spend too much time on these areas, but they need to be included so that the whole drug use process is conveyed and considered. References: Managing Drug Supply: Training Series; Trainer’s Guide; M13- Appropriate Drug Use; Management Science for Health, second edition. Further reading: Guide to Good Prescribing: A practical manual; WHO Chapter 1: The process of rational treatment, page 7
MMS: recap the discussion on aspects of irrational drug use briefly with this slide and the following 2. NSS: Diagnosis: Inadequate examination of patient Incomplete communication between patient and doctor Lack of full medical and medication history e.g. Rifampicin in Tb treatment and Stavudine (d4t), EFV potential for teratogenicity Prescribing: Extravagant prescribing: Expensive drugs are used when less expensive equivalents are available. Over-prescribing: Prescribed drugs are not needed, or the dosage is too high. Patient has gained weight after ART and dosage is not changed. Incorrect prescribing: The wrong drugs are selected for the patient’s condition. Under-prescribing: Needed medications are not prescribed, or the dosage is inadequate. Multiple prescribing; Many drugs are used when fewer would have the same effect.
MMS: recap the discussion on aspects of irrational drug use. MSS: Dispensing: Incorrect interpretation of the prescription Retrieval of wrong ingredients Inaccurate counting, compounding, or pouring: lack of Pediatric ARV formulations Inadequate labeling Unsanitary procedures Packaging: Poor-quality packaging materials Odd package size, which may require repackaging Unappealing package
