Therapeutic drug monitoring. .pptx

Pharmacy practice

1. Therapeutic drug monitoring Dr. Arpitha Anil George Assistant Professor Pharm . D, PGDM

2. Syllabus Relevant CO no Relevant LO no Learner Outcome(LO) learners will be able to…. Specific learner outcomes ( SlOs ) Learners will be able to ….. Bloom’s Level PO Therapeutic drug monitoring CO703.4 CO703.4.1 Students will be able to explain the importance and process of TDM and discuss its application in clinical practice. 1. Define therapeutic drug monitoring. 2. Explain the need for TDM in patient care. 4. Discuss the current scenario and challenges of TDM in India. Understand (BT-2), Analyze (BT-4 PO1, PO2 CO703.4 Understand the need, factors, and practice of therapeutic drug monitoring, especially in the Indian context

3. Introduction Therapeutic Drug Monitoring (TDM) involves the analysis, assessment and evaluation of circulating concentrations of drugs in serum, plasma, or whole blood. Purpose of therapeutic drug monitoring is to: ensure the medication dose is at therapeutic range and not in toxic range Drugs with Low therapeutic index Lithium Neuroleptics Phenytoin Phenobarbital Some antibiotics • Gentamycin vancomycin Amikacin Digoxin

4. SIGNIFICANCE OF THERAPEUTIC DRUG MONITORING Therapeutic drug monitoring is for the drugs that have narrow therapeutic range . (Drugs which are below range are not effective and the drugs which have above range are toxic). small changes in concentration of such drugs, lead to no effects or toxic effect. for the prevention of ineffectiveness and toxic effects, it is important to monitor the drug that has narrow therapeutic range. Therapeutic drug monitoring is important for optimization of dosage according to therapeutic response seen in particular patients.

5. Therapeutic drug monitoring is to detect the changes in pharmacokinetic parameters of drugs in certain patients due to disease or any influence condition. TDM is very helpful for drugs which shows saturable metabolism like with Phenytoin. TDM used for those drugs who has poorly defined the end point or difficult to predict the clinical effect. example: immunosuppressant drugs Therapeutic drug monitoring indicating to established relationship between concentration of drugs in plasma and its therapeutic or toxic effects. Therapeutic drug monitoring is important for those drugs which follow non-linear kinetics. Therapeutic drug monitoring is important to investigate unexpected lack of efficacy.

6. NEED OF THERAPEUTIC DRUG MONITORING There is indication of TDM if the consequences of overdosing and underdosing are serious. TDM is indicated if there is a small difference between a therapeutic and toxic dose range. TDM is indicated if there is a certain change in the physiologic state of patient that may unpredictably influence the circulating drug concentrations. TDM is indicated because of drug interaction in such cases where the patient is on more than two drugs. There is need of TDM to establish therapeutic regimen in several physiological conditions like; pregnancy, neonate, children, elderly; and pathological conditions such as renal disease, hepatic disease, etc. There is need of TDM when there is unexpected lack of efficacy or toxicity. TDM helps in monitoring patient compliance.

7. Limitations of Therapeutic Drug Monitoring: TDM is unnecessary performed for wide therapeutic range drug. TDM is also unnecessarily or no need to perform for those drugs whose pharmacological effects can be clinically quantified. It is not applicable for those drugs who follows linear kinetic. Clinical outcome cannot be correlated to either dose or plasma concentration for certain drugs.

8. FACTORS AFFECTING THE THERAPEUTIC DRUG MONITORING There is lack of patient compliance leads to insufficient plasma drug concentration to achieve optimum therapeutic effect. There is influence of different ages such as; neonates, children and elderly on various pharmacokinetic parameters which results into alteration in the therapeutic response as well as plasma drug concentration. According to gender and the condition of pregnancy, alteration in the physiological parameters occurs which leads to variability in pharmacokinetics of the drug. There is also influence of various pathological/disease conditions such as; hepatic, renal, and respiratory on the pharmacokinetic properties of drug. Thus, it may cause difficulty in the estimation of TDM.

9. Drug Interactions: one drug affects the pharmacokinetic as well as pharmacodynamic profile of other drugs which results into alteration in the response of drug which cause discrepancy in the TDM estimation. Many practitioners prescribed alternative system of medicine such as; ginseng, liquorice , tannic acids, plantain, hawthorn and kyushin , which has documented drug interaction with many of modern system of medicine i.e. allopathy medicine which resulted into alteration in the plasma concentration and therapeutic response. Other factors such as, environmental influences also affects the therapeutic response of drug through altering in the pharmacokinetic profile

10. INDIAN SCENARIO OF TDM In India, therapeutic drug monitoring was introduced in 1980s In the India, there is involvement of two main departments in TDM services,by large teaching hospital where the services are provided by the clinical pharmacology department and the other is private sectors who are dealing with estimation of drug by clinical biochemist department. In 1980 to 1990, TDM service was began in small way with use of simple highperformance liquid chromatography technique by one or two research assistants in teaching hospital for drug analysis. After decades of 1990 there are increased in the TDM services and growth of laboratory with increased in the staff and instrumentation facility in the TDM.

11. In every year there is improvement in the TDM services indicated by increased in a greater number of drugs and the number of requests for TDM. Computerization and the availability of simple technique/method with use of highly sophisticated instrumentation have made this service available even in rural areas. Despite this, there are also increased in the service centre , while the TDM remains within the boundaries of department of clinical biochemistry which are only associated with 'drug estimation but not participate in the monitoring and interpretation service. Only in few places there is existence of ideal team of TDM which comprises of a clinical pharmacist, clinical pharmacologist, and analytical scientist. there are limited data are obtained and physician are not fully trained for the interpretation of TDM results

12. Today TDM service is also available for the outpatient clinic which is sometime run twice a week with huge handling of new cases as well as old cases. There are also sufficient staffs of pharmacists, technicians, and medical officers are involved in the collection of history, sample collection and drug analysis. there are separate senior clinical pharmacologist teams involved in the monitoring services as well as they are associated with providing the advice on dosage adjustment, managing of patient compliance and identification of adverse reactions. In most of TDM centre , there are use of automated equipment and ready to use kits for estimation of drug and metabolites by using the fluorescence polarization (FPIA) and enzyme mediated immunoassay (EMIT) techniques. Advantages here is short turnaround times and ease of use.

13. Thank you