Pharmacology - Block 3 - Part 7

davidwurbel7's version from 2016-07-28 12:55

Thyroid Hormone

Question Answer
Preparation of choice in thyroid replacement therapyLevothyroxine sodium (L-T4 )
Not preferred for routine use; is cardio-toxic, therefore not preferred in CV diseasesLiothyronine sodium (L-T3)
A mixture of T4 and T3, very rarely usedLiotrix
A dried animal thyroid gland extract not recommended because of proteinThyroid Desiccated
This condition is hypothyroidism in infants leads to cretinism. This is characterized by irreversible mental retardation and dwarfism. This is the most common preventable cause of mental retardation in the world. Treatment includes thyroxine supplementationCretinsim
An end state of severe, long-standing and untreated hypothyroidism. It is a medical emergency characterized by deterioration of mental status; progressive weakness; hypothermia, hypoventilation, hypoglycemia, hyponatremia , water intoxication shock, stupor, coma, and deathMyxedema coma
DOC for hypothyroidismT4
T3 can be addition drug to T4 is this emergency conditionMyxedema Coma
Drug that inhibits the synthesis of thyroid hormoneThioamides
Among the thioamides, this drug is more potent and longer actingMethimazole
Propylthiouracil and methimazole are examples of this class of drugsThioamides
DOC for hyperthyroidismMethimazole
DOC for hyperthyroidism during pregnancyPropylthiouracil
The mechanism of action inhibit hormone synthesis by inhiniting thyroid-peroxidase which inhibits the oxidation, iodination and couplingThioamides
Inhibits peripheral conversion of T4 to T3Propylthiouracil
DOC for thyroid stormPropylthiouracil
Adverse effect of this include lupus-like reaction, hypothyroidism, arthralgia and rarely agranulocytosisThioamide
If agranulocytosis occurs, stop thioamides and administerG-CSF
This class of drug can be used in thyroid storm and is most important in preparing the patient for surgeryIodides
The mechanism of action inhibits the hormone release through blockade of thyroglobulin proteolysis. It also decreases the size and vascularity of hyperplasic thyroid gland. The gland becomes more firmIodides
This is a mixture of 5% Iodine and 10% Potassium iodide. It is given together with thioamides before surgical resection of the glandLugol’s Solution
Isotope of used in treatment of thyrotoxicosis. Oral administration that is taken up and concentrated in thyroid follicles. It emits gamma rays which destroys the gland. Contraindicated in pregnancyIodine 131
In the treatment of Grave's Disease, this class of drugs can be added to prevent cardiac effectsBeta-Blockers
An acute form of hyperthyroidism. Results form inadequate treatment of hyperthyroidism conditions like Graves disease or toxic goiter and precipitated by infection for stress.Thyroid Storm
Clinical features include fever, tachycardia, nausea, vomiting, diarrhea, agitation and confusion, coma and deathThyroid Storm
Treatment include IV fluids, antipyretics, propylthiouracil, iodidesThyroid Storm

Antidiabetic Drugs

Question Answer
Lispro insulin, Aspart insulin and Glulisine insulin are examples of this type of insulin preparationsUltra-Rapid Acting
Regular insulin is an example of this type of insulin preparationsRapid Acting
NPH insulin is an example of this type of insulin preparationsIntermediate Acting
Insulin detemir and Glargine insulin are examples of this type of insulin preparationsLong Acting
The onset of action S.C injection is 15 minutes. The duration of action is 3-4 hoursUltra-Rapid Acting
The onset of action S.C injection is 45 minutes. The duration of action is 5-8 hoursRapid Acting
The onset of action S.C injection is 1-2 hours. The duration of action is 16-24 hoursIntermediate Acting
The onset of action S.C injection is 1-2 hours. The duration of action is 13- >24 hoursLong Acting


Question Answer
They can be taken 5 minutes before meal and their short duration of action decreases the risk of late postmeal hypoglycemia. Used to control postprandial hyperglycemia. Usually administered with intermediate acting preparation to control baseline glucoseUltra-Rapid Insulin
Suspension of insulin in a complex with zinc and protamine. Given subcutaneously ,maintains the basal insulin level to control blood glucose between the meals. When mixing with regular / ultra-short insulins good care should be taken. they should not be combined until it is time to inject, otherwise they bind to each otherIsophane (NPH) Insulin
Insulin analogue with interchange of lysine and proline at 28 & 29 positions of beta chain. Dissociates more rapidly into monomers and the advantages are - faster absorption (ultra rapid onset of action ), suitable to inject just before the meal and less hypoglycaemiaLispro Insulin
Glycine is substituted for asparagine at the A21 position and two arginine molecules are attached to the B chain. Designed to provide a constant (peak less) basal insulin supply throughout the day. Slow onset of action, maintains flat level (no PEAK) of insulin for prolong period (>24 hrs) then fall in the actionGlargine Insulin
This class of drugs bind to an ATP-sensitive K+(KATP) channel on the cell membrane of pancreatic beta cells. This inhibits a tonic, hyperpolarizing efflux of potassium, thus causing the electric potential over the membrane to become more positive. This depolarization opens voltage-gated Ca2+ channels. The rise in intracellular calcium leads to increased fusion of insulin granulae with the cell membrane, and therefore increased secretion of insulinSulfonylureas
Adverse effects include Hypoglycemia, allergic reactions ,weight gain. Contraindications - Sulfa drug hypersensitivitySulfonylureas
Tolbutamide and Chlorpropamide are examples of this type of oral hypoglycemic agents1st Generation Sulfonylureas
Glipizide and Glyburide are examples of this type of oral hypoglycemic agents2nd Generation Sulfonylureas
Adverse effects include hypoglycemia, allergic reactions ,weight gain. Type-II DM patients ,especially who are not obese2nd Generation Sulfonylureas
Contraindications include hepatic or renal insufficiency: delayed excretion of the drug result in its accumulation and may cause hypoglycemia. Cautious use in CV diseases & elderly pateints (hypoglycemia). Pregnancy (risk of hypoglycemia in the newborn). Porphyrias. Sulfa drug hypersensitivitySulfonylureas
Short acting, Less hypoglycemic episodes, so is used to treat Type-2 Diabetes in elderlyTolbutamide
Prolong hypoglycemia ,so not good for Elderly patients. Ant-abuse (disulfiram) like reaction. Used to treat Diabetes InsipidusChlorpropamide
Shortest acting, less potent than glyburide. Relatively less incidences of hypoglycemia – safe in elderly patientsGlipizide
Repaglinide and Nateglinide are examples of this class of drugsMeglitinides
Acts similar to sulfonylureas, stimulates insulin secretion by blocking ATP dependent potassium channels of B-cells. Best used to control post-prandial hyperglycemia in type 2 DM. Safe in sulfa allergic patients. Hypoglycemia is main side effect. Also causes renal and liver failureMeglitinides
An euglycemic drug – Do not produce hypoglycemia. No Weight gain, so preferred in obese patientsBiguanides
Metformin is an example of this class of oral hypoglycemic agentBiguanides
The mechanism of action is ↓Hepatic gluconeogenesis. Slows down the glucose absorption from GIT. Stimulates glucose uptake & utilization by tissues (skeletal muscle). ↓ Plasma glucagon levelMetformin
Besides Type 2 DM, metformin can be used to treat this conditionPolycystic Ovary Syndrome (PCOS)
Adverse effects include Nausea and vomiting, Metallic taste, Lactic acidosis, Vitamin B12 deficiency and Weight lossMetformin
Contraindications include all conditions that predispose to acidosis, renal diseases and CHFMetformin
Thiazolidinedione adverse effects include hepatotoxicity. This drug has been withdrawn from the marketTroglitazone
Thiazolidinedione adverse effects includes an increased risk of myocardial infarction & heart failure. Hepatotoxicity not seenRosiglitazone and Pioglitazone
The mechanism of action of this class of oral hypoglycemic agents is binding to a nuclear receptor (peroxisome proliferator activated receptor, PPAR), which regulates the transcription of several insulin responsive genesThiazolidinediones (Glitazones)
Effects of this oral hypoglycemic agents is increase the target tissue sensitivity to insulin & reduce Insulin resistance, no hypoglycemia and delayed effectThiazolidinediones (Glitazones)
Adverse effects include hepatotoxicity and cardiovascular diseasesThiazolidinediones (Glitazones)
MOA: The drugs are competitive inhibitors of the intestinal brush border enzyme alpha-glucosidase involved in the breakdown of starches into simple sugars. This leads to a decreased monosaccharide formation from carbohydrates in the upper small intestine and therefore the absorption of monosaccharides from duodenum and upper jejunum is reducedAlpha-Glucosidase Inhibitors
Used in type 2 DM ,administered just before ingestion of first portion of each meal . Most suitable in patients with predominantly postprandial hyperglycemia.Alpha-Glucosidase Inhibitors
Adverse effects include Flatulence (up to 40%), Diarrhea (up to 20%), abdominal pain (7%). Hypoglycemia is not significant. Contraindicated in Inflammatory bowel diseaseAlpha-Glucosidase Inhibitors
A small peptide hormone that is released into the bloodstream by the β-cells of the pancreas along with insulin after a meal. This is completely absent in individuals with Type I diabetesAmylin
An injectable amylin analogue that allows patients to use less insulin. Can be used as adjunct therapy to control postprandial glucose excursionsPramlintide
Gut hormones that are secreted from enteroendocrine cells into the blood within minutes after eating and stimulate a decrease in blood glucose levelsIncretins (GLP-1 Agonists)
GLP-1 agonistsExenatide
Mechanism of action is to increase incretin which inhibit glucagon release, which in turn increases insulin secretion, decreases gastric emptying and blood glucose levelsSitagliptin
Mechanism is to block Sodium/glucose cotransporter 2 causing blood glucose to be eliminated through the urineGliflozin
Clinical features include sweating, anxiety, palpitation, tremor dizziness, headache, behavioral changes, visual disturbances, fatigue and weakness. Mental confusion, seizures and comaHypoglycemia
A patient that is also on this drug along with insulin may block the awareness of hypoglycemia in that patientBeta-Blockers
Only insulin that can be administered IVRegular Insulin
The most common route of administration of insulin is thisSubcutaneous
Adverse effects include Hypoglycemia, Allergic reactions, Lypodystrophy and Local reactions at the site of injections, Weight gain and Insulin resistanceInsulin
This is generally caused due to delay in intake of meal after insulin injection; Inadequate carbohydrate in take; physical exertion and high dose of insulinHypoglycemia
Clinical features include sweating, anxiety, palpitation, tremor dizziness, headache, behavioral changes, visual disturbances, fatigue and weakness. Mental confusion, seizures and coma occur in severe hypoglycemiaHypoglycemia
Hypoglycemia is treated with this if the patient is able to protect their airwayOral Glucose
Hypoglycemia that is severe or if the patient is able to protect their airwayIV Glucose and Glucogon injection