Diabetes mellitus 1 عبد هللا الزعبي. pharmacology. Shatha Khalil Shahwan. 1 P a g e

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1 Diabetes mellitus 1 pharmacology عبد هللا الزعبي 1 P a g e 4 Shatha Khalil Shahwan

2 Diabetes mellitus The goals of the treatment of diabetes 1. Treating symptoms 2. Treating and Preventing acute complications ( diabetic ketoacidosis, hyperosmolar non-ketotic state) 3. Limiting and slowing down the progression of long-term complications (micro and macro-vascular disease, eg; retinopathy, nephropathy, neuropathy, and atherosclerosis ) 4. Improving the quality of life ( doubtable ) Is it worth it to treat diabetes??? Uk s prospective diabetes study (2003) is one of the most important studies done, showed that the micro and macro-vascular diseases could be decreased, particularly with the introduction of the new generation of drug..> so it is worth it 2 P a g e

3 -In diabetic patients, the relative insulin secretion decreases with time, even with treatment >>>And that is due to the progressive destruction of the beta cells of the pancreas>>> eventually >>> no production of insulin -Type 2 DM >> there is great glucose intolerance and significant reduction in insulin secretion or activity How do we start txt? -Once we find that there s some sort of glucose intolerance or decrease in insulin production, firstly, we advise the patients to modify their diet and life style, and to exercise more, etc, which will help in reducing the symptoms but only for a limited time, then we start a single drug therapy ( which is usually oral medication), later on when this drug becomes not effective enough, we move on to the combination therapy (of several oral medications ) at some point when the beta cells of the pancreas become completely destructed, and there would be no response to the combination therapy >> we have to give insulin here -Sometimes both oral medications and insulin are used at the same time. -Usually the single drug therapy works for no more than 5 yrs, then you have to start a combination therapy( 5-15 yrs), and at the end (not before yrs after starting oral medications) we have to give insulin as a therapy When to use insulin?? -in Type 1: diabetic patients have to take insulin from the start -in Type 2 : we give insulin when the oral medication stops working and the glycemic control becomes poor -in Gestational diabetes or if the pt is already a diabetic (weather ( type 1 or 2) >> cuz pregnancy is diabetogenic,>> the hormonal profile of pregnancy leads to generation of diabetes in someone who is susceptible, or worsening of the case if 3 P a g e

4 the pt is already a diabetic >> so the pregnant woman can t just take oral medication, she has to take insulin bcz diabetes effects the baby severely -in Acute complications: like Diabetic KetoAcidosis (usually in type 1), nonketotic hyperosmolar state (Type 2) >> life-threatening emergency >>intense/immediate course of treatment (can t use oral medication )>> insulin is a must -in a Stressful situations: like surgery, systemic serious infections, injuries >> need intensive insulin therapy, bcz the cortisol and epinephrine (sympathetic) that are released in such conditions are counter-regulators to the insulin which would worsen the condition of diabetic patients) The most effective treatment of diabetes is insulin There are different types of insulin which differ from each other in the Onset time, the peak and Duration of action. Types of insulin 1. Regular insulin ( similar to the human type of insulin) >> like a racing car>> (it s going to get u to your destination ) 2. Rapid acting insulin >> like air craft >> it going to get you to your destination at a much lesser time) 3. Long-acting insulin ( like a running shoes >> very slow ) 4. Intermediate acting insulin ( like a bicycle >> different onset, peak and duration of time ) Let s go into details : 1. The regular insulin : -rapid onset insulin ( min ) - the peak of action will take about 1 hour -the duration is not that long ( 4-8 hours ) -SC or 4 P a g e

5 -IV injection in emergency ( not perfect in emergencies bcz the onset in not immediate 2. Rapid acting insulin -Immediate onset -Higher peak -Reaches its peak quicker -Duration >>> shorter ( which is an advantage in emergencies bcz we want a predictable Toxicity profile ) -SC -IV ( mainly ) The 2 previously mentioned types are not that practical for a patient who takes insulin at home, bcz they have to be taken 5-6 times a day >> and this is bad specially for pts who are afraid of injections 3. Intermediate acting insulin -Intermediate onset ( 30-60min ) -Peak: it takes longer to be reached in h -Longer duration of action ( 12-14h) >> great advantages in the use of home-based therapy -The intermediate insulin was made by coupling the insulin to the protamine>> making complexes that are less soluble which causes the insulin stay in the subcutaneous tissue for a longer time until it gets absorbed from that area of injection (this is what effects the peak and the DOA) -Not used in emergency condition but only as a maintenance of insulin treatment -Only SC 5 P a g e

6 4. Long acting insulin -Very long duration of action that could reach up to 24h -Electricity profile: (Iso-electric point of the drug makes it precipitate at the site of injection) >> the absorption will be even slower than the intermediate insulin -SC only -Not in emergencies -No mixing with other type of insulin in the same syringe because it will change the characteristics (electrical profile) If all of the insulin diagrams were plotted together, we will notice that -the Rapid acting insulin has the highest peak, which makes it the most preferable option in emergencies(blue) -the long acting insulin is peak-less (start at a level and maintain it throughout the DOA), which is good and bad Good : because it mimics the basal level of insulin which is enough to maintain the normal physiological function Bad : the normal secretion pattern of insulin in the body as the figure illustrates down is not in a consistent concentration through the 24 hours (we have what is called meal induced surges of insulin secretion that happen as a response to the 6 P a g e

7 absorption of glucose in blood ) so the long acting insulin isn t sufficient to simulate and compensate for those surges of insulin -Note that, most diabetic patients have some sort of fasting hyperglycaemia (bcz the basal secretion of insulin is not sufficient to deal with glucose level in the blood) so when they wake up in the morning they have a very low basal insulin level. -The pharmacological treatment has to simulate the pattern of insulin secretion ->>> simulate the basal type of secretion :The intermediate and the long acting (long duration of action, not very high peaks, and can be maintained for a while) ->>>If I want to simulate the meal induced secretion of insulin: regular and rapid acting insulin will do the job (Rapid onset, high peak, Not maintained for a long time ) -And that what happens in the therapeutic strategy >>> we give the patient one injection of the long acting insulin at bed time and that will maintain the basal level of secretion for the next night ( 24 h ) and to maintain the meal induced secretion of insulin we give the patient the regular or the rapid acting insulin prior to ( or with ) the meal..but Since the long acting insulin is peakless and unpredictable>> in the modified therapeutic strategy, they changed the long acting insulin to the intermediate insulin given at bed time and compensating for the meal induced surges by the regular or the rapid onset insulin given once or twice 7 P a g e

8 -Something that works even better is the premixed preparation ( usually the regular and the intermediate insulin mixed in one syringe before being injected ) >> usually this is given to the patient twice a day ( may be 3 times a day) taking into account that the intermediate insulin will maintain the basal level secretion of insulin for the whole day and hopefully the regular or rapid insulin will simulate the meal induced insulin (The benefit of using the first regimen is that there is less injections which is better also it is good for pts who don t have a caretaker at all times on the other hand it s not so great bcz the long acting insulin is peakless and unpredictable regarding the effect, benefit, and side effect) -The biggest need of insulin usually happens in the morning bcz the concentration of insulin decreases overnight, >> so the dose is subdivided into 2/3 in the morning and 1/3 in the evening, plus that we are afraid of side effects particularly hypoglycemia happening at night 8 P a g e

9 -The endocrine system treatments follow the rule of trials and error>> try a treatment >> tell the patient to come back >> measure the glycemic control parameter >> not normal >>> increase or decrease the dose ( or change the medication ) The devices used in administering insulin: 1. The insulin syringes 2. The pen : automated: you switch it to the dose you want and inject it, it cause much less pain( preferred )> ( thermo-keeper the person can take it all the time ( 3. The insulin infusion pump: it is implanted subcutaneously and it has sensors that sense the amount of glucose and it s automated to pump insulin according to the need of the body (expensive) Additional info by the dr. -In the U.S, inhalation insulin was introduced to the market, but it doesn t fit the guidelines (still in trials, waiting for the post marketing records ) -A product that fit the guideline is a product with proven efficacy and side effects profile and toxicity profiles Sites of injection: Thighs, arms, abdomen, and buttoks ( they differ in the onset of absorption ) The rotation policy is recommended ( do not inject insulin in the same place every time ) 9 P a g e

10 Side effects: hypoglycemia -There are alarming symptoms for hypoglycemia like headache, paresthesia around the mouth, anxiety, vertigo, confusion, diaphoresis, tachycardia, - they result from the overstimulation of the sympathetic system as a result/response to too much insulin (counter regulatory mechanism) -Usually diabetic patients who take insulin have comorbid diseases like hypertension ( people with HTN take beta blockers for the treatment of HTN ) >>> SO here the patient is a diabetic taking both insulin and beta-blockers >>>which is BAD >> bcz beta-blockers will mask the symptoms of hypoglycemia >> the patient will be at a very dangerous level of hypoglycemia that would affect the brain but he can t sense it >>so>> nonselective B blockers is contraindicated in diabetic patients using insulin -be aware that selective b-blockers may lose its selectivity if used too much or in high doses ( reduce the dose in diabetic patients ) - the patient incompliance of insulin is bcz of the symptoms of hypoglycemia which impedes their lives severely -Hyper and hypoglycemia present with the same symptoms -Imagine that you have a patient in Coma, and you want to give him empiric treatment (you don t know the level of glucose in his blood) >> are you going to give him something sweet or give him an insulin injection?????? We will give him something sweet >>> the worry here (patient in a coma )is the hypoglycemia which is much mooore dangerous than hyperglycemia >> irreversible brain damage and probably death 10 P a g e

11 Side effects of using insulin injection : 1. Lipoatrophy that results from the use of air purified insulin that may cause an allergic reaction in the site of injection 2. Lipogenic effect leads to lipodystrophy These are why we recommend changing the sites of injection (rotation policy) And these side effects are not just bad bcz of the looks of them, but also bcz the absorption becomes faster at some sites than other sites and here is where the fluctuation of glucose level happens because we don t know where the insulin is going to be absorbed quickly or slowly These 2 side effects are reduced due to the advanced way of using recombinant DNA technology in the production of insulin Hyperglycemia is the problem in diabetes >>how does it happen??? The problem is that there is too much sugar absorbed into the blood without being able to induce enough secretion or production of insulin from the pancreas, or there is a problem in insulin secretion due to counter regulatory mechanism (poor uptake of glucose by the peripheral cells) the body cells are unable to take up the glucose out of the blood so hey have change their metabolism > the whole metabolism of the body will be changed > The organs contributing to this problem are: 11 P a g e

12 - Liver : compensating by increasing the hepatic glucose output (gluconeogenesis and releasing the glucose from the liver to the blood ) but that glucose won t get into the cells bcz there is no insulin >>more glucose in the blood>> worsening hyperglycemia - Adipose tissue: with the loss of lipogenic effect tries contribute to the metabolism by producing more fatty acid to be utilized >> that will lead to a higher insulin resistance in the peripheral tissue >> more gluconeogenesis by the liver>> hyperglycemia>> negative effect of insulin secretion from the pancreas - Kidneys: also play a role in the reabsorption and the execration of the glucose so when there is too much glucose in the blood the kidneys throw out/ excrete the excess in the urine >> glucose urea This mechanism will stop at some point, because the glucose damaged the kidney>> nephropathy >> the excretion mech. Is impaired and the hyperglycemia even worse.. - On top of that, the brain >> contributes to all these factors leading to worsening of the condition of the pt How to treat that?? By using oral medication hoping that we can reduce some of these problems 12 P a g e Done by: Shatha Khalil Shahwan