Welcome to IS PHARMACOLOGY DIFFICULT Podcast ! I am Dr Radhika Vijay, in today's episode, I will change the Queen's name of the fairytale of Pharmacology episode of today and it is Drug Dosage types. Today I will discuss this topic as it will form the building blocks to furnish the tail episodes of pharmacokinetics. Well, discussion starts from Fixed Dose in which I will state the fact that desired of drug can be attained well enough below the toxic dose. Second is variable dose with crude adjustments, in which I want to state that fine adjustments make insignificant differences and therapeutic endpoints are hard to monitor, and there may be variable situations, all explained well with apt examples. Third one is variable dose with fine adjustments, in this a vital function is closely monitored repeatedly and it provides endpoint, that is difference from last dose type. Fourth is maximum tolerated dose abbreviated as MTD, its used when ideal therapeutic effect is not achieved due to unwanted side effects, way of finding it is to monitor plasma concentration or to increase dose and follow another procedure, details discussed in podcast episode, last one is minimum tolerated dose, in this doses providing relief are too toxic to tolerate, compromise is to be done on safety grounds, it becomes a difficult unachievable task.That's all folks for today! Hope you all liked it, till next episode, do follow me here, do rate and review on ITunes, Apple podcasts, stay tuned, thank you!

Welcome all to IS PHARMACOLOGY DIFFICULT Podcast! I am Dr Radhika Vijay, in today's episode, I will be dedication my talks to exclusively plasma half life, abbreviated as t1/2, its defined as time taken by drug to reach half of its initial concentration. First case to talk about today is a drug with one compartment distribution and first order elimination, in this case the semilog plasma concentration time plot has two slopes, the initial sharply declining alpha phase which refers to distribution, and later less declining beta phase which refers to elimination. It is the beta slope which we refer to half life of a drug. In reality most drugs have multi compartment distribution and multi exponential decay, so its the beta slope which we call half life, generally ignoring alpha phase, "k" is elimination rate constant of a drug which is derived from CL(clearance) divided by V (volume of distribution), in another equation, t1/2 equals to 0.693 multiplied by volume of distribution divided by clearance. Now important point to be noted is that in first order kinetics, volume of distribution and clearance do not change with dose, so t1/2 remains constant, while its not so in zero order kinetics. So all these important implications make lot of sense while evaluating pharmacokinetic parameters, Then I will wind up today's episode with examples of few significant half lives of some important clinically relevant drugs, till next episode, do follow me here, do rate and review on ITunes, Apple podcast, thank you!!

Welcome all to IS PHARMACOLOGY DIFFICULT Podcast ! I am Dr Radhika Vijay, In today's episode, I will continue more details of Michaelis Menten kinetics or mixed order kinetics or saturation kinetics, It is for high dose aspirin, dicoumarol, warfarin, digoxin, tolbutamide, phenytoin, etc.It is a dose dependent process, at small doses it follows first order kinetics and as the dose increases, plasma concentration increases, then metabolising enzymes or elimination processes become saturated, and the kinetics order changes from first order to zero order kinetics. The graph also changes respectively on arithmetic and logarithmic scale. Its shape is unique , its changes from linear too curvilinear and opposite in log scale. Its totally opposite in case of absorption, which is explained in the audio file so do refer to the episode. This change of order of kinetics is quite risky as slight change in dose may shoot up plasma concentration and result in toxicity so such drugs need close monitoring and need to be handled carefully. Then. a little word will be given about blood flow dependent kinetics in which for some drugs elimination would exceed far beyond the dose of drug entering the organ of elimination like liver, kidney, hence their elimination is dependent on blood flow, so with this wonderful and novel concept, do follow me here, stay tuned, do rate and review on ITunes, Apple podcasts, thank you!

Welcome to IS PHARMACOLOGY DIFFICULT Podcast ! In today's episode, the centred topic is all in all plasma concentration curve plotted against time and also logarithmic part of it, the former is steeply linear, latter is curvilinear. The fall in plasma concentration is not dependent on plasma levels of drug in body, rather they fall at constant rate. This zero order kinetics is also called as Capacity limited elimination, secondly its also called as Michaelis menten kinetics, also called as mixed order kinetics or saturation kinetics. The reason for so many synonyms will be clear with the description . The drug elimination reaches a saturation over higher therapeutic range hence called as saturation kinetics or capacity limited elimination, the order too may change from first order to zero order for few drugs, plasma concentration increases disproportionately with increase in dose. Examples of drug will compliment this whole descriptive part, then I will tell you one more term for zero order kinetics i.e. non linear elimination. All the synonyms of zero order kinetics , their specific descriptions, examples all storming your brains with loads of knowledge and information, require a special halt for the episode, leaving the untold part to be discussed in future, so do follow me here, rate and review on ITunes, Apple podcasts, stay tuned, stay safe, stay enlightened, Thank you!!

Welcome all to IS PHARMACOLOGY DIFFICULT Podcast ! I am Dr Radhika Vijay, in today's episode I will be talking about pharmacotherapy of the weekend with a new great topic namely Zero Order Kinetics. I will talk about three initial characteristics of Zero Oder Kinetics, firstly to comment is that constant or fixed quantity of drug is eliminated per unit time. Secondly , the rate of elimination is totally independent of plasma concentration of drug and it follows a fixed rate, hence increasing the dose does not affect rate of elimination of drug.Thirdly to narrate, very importantly, the plasma half life, i.e. t1/2 is not constant, it changes with plasma concentration of drug, it increases with increasing plasma concentration, and few drugs to comment which follow purely zero order kinetics at all plasma concentrations is ethyl alcohol, its a true unique example of this order of kinetics of elimination.The story will continue further for zero order kinetics in upcoming episodes, till next one, wish you all a real safe and happy weekend, do follow me here, rate and review on ITunes, Apple podcasts, stay tuned, thank you!!

Welcome all to IS PHARMACOLOGY DIFFICULT Podcast! I am Dr Radhika Vijay, in today's episode, I will be talking about the left and last two characteristics of First Order Elimination Kinetics , firstly I will discuss the log dose response v/s time graph on which I will be describing two slopes, rather two half lives of drug following first order kinetics, one is alpha slope or phase dependent upon distribution of drug, second being beta phase or slope dependent upon elimination of drug and the importance of both, next characteristic, I will be giving formula of t1/2 involving rate elimination constant and also calculation of K from slope formula and then I will tell about declining phase and negative value and also relation to tan theta, and will be talking my heart out regarding all these mathematical, statistical derivations, as to why you need to cram all these if you are weak at mathematics and trigonometry etc, till next episode and pay your ears to these crispy informative audio files, do let me know, IS PHARMACOLOGY DIFFICULT?, do follow me here, rate and review on ITunes, Apple podcasts, stay tuned, thank you!!

Welcome all to IS PHARMACOLOGY DIFFICULT Podcast ! I am Dr Radhika Vijay, today is 100th episode, in today's episode, first of all I will be narrating few words of inspiration, then I will be directly jumping on to the topic of day, in which I will continue with characteristics of first order elimination kinetics which I left midway yesterday, in this the first point today is that after around five half lives, drug reaches a steady dtate level which is called as plateau level, at this level, if we increase drug dose further, it will not have any effect, and the goal should be to maintain the dose at this level, neither increase it nor decrease it, deceasing dose will have no effect and increasing dose may lead to toxicity, next important characteristic of today is simply a wonderful concept, it says that for a drug following first order kinetics, if dose is doubled, it increases its duration of action by one more half life, I have beautifully explained this whole concept via a mathematical example which you all would cherish to listen to, so these two points mark today's episodes end and before I wave you all a Goodbye, I request you all to check my thank you note alongwith the statistics till date in today's 100th episode special live streaming on Youtube channel of mine, till then, do follow me here, rate and review on ITunes,Apple podcasts, you are all great, simply great and the best of best audience, love to all, stay tuned, thank you!!

Welcome all to IS PHARMACOLOGY DIFFICULT Podcast ! I am Dr Radhika Vijay, in today's episode I will be furthering the topic of Kinetics of Drug Elimination, under which specifically I will be starting off with First order Kinetics, its specifications and characteristics. The first important point is that constant fraction of drug is eliminated in constant time period. It will be clear with an example, Then second important point is that by increasing plasma concentration of drug, rate of drug elimination also increases, it is directly proportional. The plasma half life is constant for first order kinetics of drug elimination.Next important point is about the graphs and their shapes in normal dose response curve against time as compared to same curve plotted as logarithms of plasma concentration against time.It will be crystal clear as I will give exact description and shapes etc. Last important point of the day today is that about 97% of drug is eliminated in about 5 half lives. Well, these were few main characteristics of first order kinetics, and few more important left for tomorrow, Tomorrow is OUR 100th EPISODE!!!! LET US MEET LIVE AT 15:00 HRS IST(Indian Standard Time), Till then, do follow me here, rate and review on ITunes, Apple podcasts, stay tuned, thank you!!!!!

Welcome all to IS PHARMACOLOGY DIFFICULT Podcast ! I am Dr Radhika Vijay, in today's episode, First of all, wish you all a very Happy WORLD HEART DAY!! To mark the essence of today, remember three most important points for the day, which says firstly never lose your heart, because it is the best way to deal with one's problems effectively, secondly, hear your heart and heart your health, thirdly, never break any heart, try to win over as many hearts as possible, because that is the essence of this day, wishing you all a very happy world heart day!! Now, coming over to the topic of the day, I will first tell you all that plasma half life along with the apparent volume of drug distribution forms the base of drug schedule of any drug.Then I will talk about Clearance, telling the essence of it, I will derive a proper definition of this important term, give an explanatory diagram and then derive a formula for Clearance , which along with the diagram, will become crystal clear. Then I will be heading over to the teaser topic of tomorrow, different orders of kinetics, which will be covered in tomorrow's episode, with a great advice to pay heart, and attention to the value of World Heart Day, I will call to halt today's session, till next episode, do follow me here, do rate and review on ITunes Apple podcast, stay tuned, Thank you!!

Welcome all to IS PHARMACOLOGY DIFFICULT Podcast ! I am Dr Radhika Vijay, in today's episode I've got a gift box for all of you namely Kinetics of elimination, a very important part of pharmacokinetics, consisting of lot of formulas, derivations, etc. It forms the basis of deriving dosage regimens, especially according to individual, The main parameters are Bioavailability (F), Volume of distribution (V), Clearance(CL). Drug elimination is sum total of metabolic inactivation and excretion processes.I will tell about two more parameters and give definitions, firstly plasma half life (t1/2), in this plasma concentration of drug falls of 50% of original value, secondly, Biological Effect half life, in this, pharmacological effect declines by half. The difference between the two i.e. plasma half life and biological effect half life is clear, concise and important, hope you all understood well, the parameters like bioavailability and volume of distribution of drug have been discussed in detail , hence as a teaser, in upcoming episode, I will be throwing light on Clearance of drug. This is very important, but till next episode, do follow me here, do rate and review on Itunes, Apple podcasts, stay safe, stay tuned, thank you!!