Rational Use Anti-infectives CPC rational [Autosaved]_123252.pptx

Rational Use Anti-infectives CPC rational [Autosaved]_123252.pptx

1. RATIONAL USE OF DRUGS Acknowledgemants : V.Rajini M.Pharm World Health Organisation K.Likhita and C.P. Chijioke Y13PHD1111 1 Compilation Prof. C.P. Chijioke

2. The rational use of drugs requires that: patients receive medications appropriate to their clinical needs in doses that meet their own individual requirements ( cf : personalized medicine) for an appropriate period of time, and at the lowest cost to them and their community. WHO conference of experts, Nairobi 1985 DEFINITION OF RDU 2 M.A.M.College of Pharmacy

3. Bridging the gap between pharmacology and therapeutics 1. Learn about drugs (pharmacology) and diseases. 2. Identify the patient’s problems and diagnose diseases. “diagnosis before treatment ” drug-induced/ iatrogenic diseases 3. (a) stop harmful or unnecessary drugs/therapy (b) Decide whether therapy is indicated. (c) Decide which therapy, if any is indicated. This may be drug and / or non-drug therapy. 4. Rational choice of drug, dosage regimen and route of administration. This depends on characteristics of: M.A.M.College of Pharmacy 3

4. M.A.M.College of Pharmacy 4 (a) the disease - the correct diagnosis determine the range of drugs from which to choose the drug sensitivity pattern of the disease modifies this range (b) the drug the toxicity of the available drugs the pharmacokinetic properties of the available drugs. drug interactions. (c) The patient Age (pregnancy, infancy, childhood, old age) Weight Gender Racial / genetic factors (PHARMACOGENETICS) Other diseases in the patient. Other drugs the patient is taking (drug interactions) The patient’s ability to comply with the therapy under consideration.

5. M.A.M.College of Pharmacy 5 5. Drug prescription (scope for malpractice) 6. Drug administration (ensure compliance) 7. Follow up the patient: monitor drug effects and interactions. Adjust pharmacotherapy if need be. “ primum non nocere ”

6. TYPES OF IRRATIONAL USE 6 M.A.M.College of Pharmacy

7. DIAGNOSIS- IRRATIONAL USE Inadequate examination of patient Incomplete communication between patient and doctor Lack of documented medical history Inadequate laboratory Resources 7 M.A.M.College of Pharmacy

8. PRESCRIPTION- IRRATIONAL USE Under-prescribing Incorrect / inappropriate prescribing Brand-name prescribing Extravagant prescribing Over-prescribing ( polypharmacy ) Multiple prescribing E.g. routine prescription of regular paracetamol : suppresses pyrexia (IDUx2), nephro -/ hepato -toxic Use and abuse of analgesics: address RSI chronic pain 8 M.A.M.College of Pharmacy

9. DISPENSING- IRRATIONAL 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 9 M.A.M.College of Pharmacy

10. DISPENSING- IRRATIONAL USE Dispensing fake or substandard medications: Role of NAFDAC (scratch numbers etc.) Responsibility of pharmacist ( sourcing , preparation, manufacture, compounding, mixing, formulation, preservation, storage, transportation and dispensing of medications) Reliable source is paramount: should not rely on brand-name prescribing Traditional medicines, herbal preparations, quack medicines: efficacy and safety issues, research needed to isolate active ingredients and characterize acute/ chronic toxicity profile M.A.M.College of Pharmacy 10

11. HAZARDS OF IRRATIONAL USE OF DRUGS Ineffective & unsafe treatment Antimicrobial resistance Exacerbation or prolongation of illness. Distress & harm to patient Increase the cost of treatment 11 M.A.M.College of Pharmacy

12. STANDARD TREATMENT GUIDELINES, EDL, NF etc. STGs may be defined as ‘systematically developed statements to help practitioners or prescribers make decisions about appropriate treatments for specific clinical conditions. (Evidence-based medicine: grade A=RCT etc.) NB also: Essential Drug Lists (national, hospital, WHO) Formularies (national, hospital) are approved drug listings with some treatment guidelines e.g. BNF 12 M.A.M.College of Pharmacy

13. USES OF STGs • providing guidance to health professionals on the diagnosis and treatment of specific clinical conditions • orienting new staff about accepted norms in treatment • providing prescribers with justification for prescribing decisions made in accordance with STGs • providing a reference point by which to judge the quality of prescribing • aiding efficient estimation of drug needs and setting priorities for procuring and stocking drugs. 13 M.A.M.College of Pharmacy

14. PHARMACOVIGILANCE  Relating to the collection, detection, assessment, monitoring, and pr evention of adverse effects with pharmaceutical products. Formal PV would be Pharmacoepidemiology = ‘phase 5’ clinical trial The 4 elements of an AE case are (1) an identifiable patient, (2) an identifiable reporter, (3) a suspect drug, and (4) an adverse event. Its study is necessary to prevent ADR to promote RDU. 14 M.A.M.College of Pharmacy

15. Rational use of anti-infective agents Achieve an accurate diagnosis of infection by history, examination and appropriate investigations eg blood cultures before antimicrobial Rx 2. Decide whether an antimicrobial is indicated. Decide on other treatment e.g. incision and drainage 3. If antimicrobial is indicated, then make a rational choice based on characteristics of: a) the infection identity and antimicrobial sensitivity combination chemotherapy prn to forestall resistance site, severity of infection b) the antimicrobial drug antimicrobial spectrum of the drug (narrow vs broad) mechanism of action ( bacteriostatic , bactericidal …) pharmacokinetic properties of the drug (e.g. lipophilicity , half-life) known toxicities and drug interactions cost (cost-effectiveness)

16. c) The host age (foetus, infancy, childhood, elderly) weight e.g. chloramphenicol , ivermectin sex e.g. w.r.to pregancy , breast feeding racial/ genetic factors e.g. G6PD deficiency intercurrent disease e.g.renal or hepatic impairment drug allergy or intolerance other drugs being taken drug adherence (compliance)

17. Antimicrobial prophylaxis Prone to abuse Useful for short term prevention of infection in relatively few patients, or long term prevention of narrow range of infection (NB risks of failure of prophylaxis and/or chronic toxicities with long term approach) e.g. prevention of post-op and postpartum infection such as endocarditis prevention of malaria prevention of recurrence of rheumatic fever prevention of recurrent UTI prevention of specific infections in contacts

18. Management of infection Diagnosis before treatment Prevention better than cure personal measures (education, immunization, bed nets, repellants …) environmental measures (stagnant water …) Underlying causes/ aggravating factors: avoid over-reliance on antimicrobials alone immunodeficiency: HIV, leukaemia, cytotoxic Rx immunosuppressants , immunomodulators ( anticytokines ...) (NB need for bactericidal agents rather than bacteriostatic, if immunodeficient ) immune dysfunction (diet-related?) inappropriate/ deficient nutrition (QV Ecogenetics / epigenetics ) nutritional deficiency e.g. zinc, vit A, ‘fast food’, worm infestation

19. Management of infection Tailored therapy antimicrobial agents, dietary intervention, deworming etc. other drugs/ treatments e.g. drain abscess NB inappropriate routine prescribing of paracetamol Attend to complications, associated infections Contact tracing as appropriate to find other cases in need of treatment and follow-up M.A.M.College of Pharmacy 19

20. Nutritoxi -epigenetics of chronic disease: dietary prevention and control PROF. C.P. CHIJIOKE INSTITUTION Dept of Pharmacology & Therapeutics, College of Medicine, University of Nigeria, Enugu

21. What are antimicrobials? Antibiotics?, antiviral, antiretroviral, antibacterial, antimycobacterial, antifungal, antiprotozoal, antimalarials, Anthelmintics ? i.e. need a broad-minded approach to the diagnosis of infection/ sepsis Clinical failure of antimicrobial treatment Incorrect diagnosis/ interpretation of results e.g. Staph. aureus and STD problems with adherence (compliance) dosing errors substandard/ fake drugs immunodeficiency: HIV infection, nutritional deficiencies (e.g. Zinc, vitamin A, worm infestation) abscess foreign body antimicrobial resistance (develops more readily, the simpler the organism)

22. The success of antimicrobial chemotherapy depends on achieving a drug concentration at the site of infection which is sufficient to tip the balance (‘battle’) in favour of the host. A microorganism is susceptible to an anti-infective agent if the therapeutic concentration is less than the toxic concentration. The organism is said to be resistant if the therapeutic concentration is greater than or equal to the toxic concentration.

23. Antimicrobial drug resistance: a major consequence of irrational drug use ... ... Acquired antibiotic resistance genes: ... it was assumed that the evolution of antibiotic resistance (AR) was unlikely... Nobody initially anticipated that microbes would react to this assault of various chemical poisons by adapting themselves to the changed environment by developing resistance to antibiotics using such a wide variety of mechanisms. Moreover, their ability of interchanging genes, which is now well known as horizontal gene transfer (HGT) was especially unexpected.

24. Antimicrobial abuse and misuse (irrational drug use) Widely prescribed without a proper diagnosis (M,C,S etc.), available over the counter, “self treatment” Regulation/ enforcement preferable, even at risk of some patients not receiving timely anti-infective chemotherapy: alternative is the burgeoning havoc of AMR Swann report (1969) on animal husbandry: “It is clear that there has been a dramatic increase over the years in the numbers of strains of enteric bacteria of animal origin which show resistance to one or more antibiotics. Further, these resistant strains are able to transmit this resistance to other bacteria. This resistance has resulted from the use of antibiotics for growth promotion and other purposes in farm livestock”

25. In many developing countries, antimicrobial agents are freely available ‘over the counter’, as opposed to being strictly regulated ‘prescription-only medicines’, as obtains in more developed countries. The only factor limiting overuse and abuse tends to be price. Hence the cheaper antimicrobials tend to be ineffective on account of antimicrobial resistance e.g. ampicillin , cloxacillin resistance Resistance parallels usage: implementations of policies and strategies to limit usage may eventuate in reversion to sensitivity e.g. Staph. and penicillin

26. M.A.M.College of Pharmacy 42 THANK YOU FOR YOUR ATTENTION QUESTIONS?