Pituitary Quiz PDF

 Quiz…… 1. 27 years old female 0n contraceptive pill to prevent pregnancy, unfortunately she got TB infection, her doctor was gave her 1st line antiTB drug (RIF. , INH, ETH., PYRAZ.), after 2 moths she became pregnant, Whats wrong with her ??? 2. 39 years old male got TB inf...

 Quiz…… 1. 27 years old female 0n contraceptive pill to prevent pregnancy, unfortunately she got TB infection, her doctor was gave her 1st line antiTB drug (RIF. , INH, ETH., PYRAZ.), after 2 moths she became pregnant, Whats wrong with her ??? 2. 39 years old male got TB infection and start 1st line antiTB drug (RIF. , INH, ETH., PYRAZ.), after one month he was develop yellowish discoloration of skin and sclera, Whats wrong with him?, which drugs cause that condition?, how can treat him?. 3. 45 old male patient on 1st line antiTB drug (RIF. , INH, ETH., PYRAZ.) but his condition deterorated, for that reason his physician start with him on 2nd line antiTB, Can help him by naming 4 drugs? 4. Mention groups of antiHIV drugs and name 2 drug for each group. 5. Mention the route of Acyclovir adminstration and name 2 adverse effect of each. The neuroendocrine system, which is controlled by the pituitary and hypothalamus, coordinates body functions by transmitting messages between individual cells and tissues. The endocrine system releases hormones into the bloodstream, which carries chemical messengers to target cells throughout the body. Hormones have a much broader range of response time than do nerve impulses, requiring from seconds to days, or longer, to cause a response that may last for weeks or months.  The two regulatory systems are closely interrelated. For example, in several instances, the release of hormones is stimulated or inhibited by the nervous system, and some hormones can stimulate or inhibit nerve impulses.  HYPOTHALAMIC AND ANTERIOR PITUITARY HORMONES The hormones secreted by the hypothalamus and the pituitary all are peptides or low molecular weight proteins. act by binding to specific receptor sites on their target tissues.  The hormones of the anterior pituitary are regulated by neuropeptides that are called either “releasing” or “inhibiting” factors or hormones. These are produced in the hypothalamus, and they reach the pituitary by the hypophyseal portal system.  The interaction of the releasing hormones with their receptors results in the activation of genes that promote the synthesis of protein precursors. oThe protein precursors then undergo posttranslational modification to produce hormones, which are released into the circulation. Each hypothalamic regulatory hormone controls the release of a specific hormone from the anterior pituitary.  Although a number of pituitary hormone preparations are currently used therapeutically for specific hormonal deficiencies, most of these agents have limited therapeutic applications.  Hormones of the anterior and posterior pituitary are administered (IM), SQ(Subcutaneous), or intranasally because their peptidyl nature makes them susceptible to destruction by the proteolytic enzymes of the digestive tract. Corticotrophin (CRH)  Corticotropin-releasing hormone (CRH) is responsible for the synthesis and release of the peptide pro-opiomelanocortin by the pituitary. ACTH  ACTH is released from the anterior pituitary  is a product of the posttranslational processing of this precursor polypeptide.  Normally, ACTH is released from the pituitary in pulses with an overriding diurnal rhythm,  with the highest concentration occurring in the early morning and the lowest in the late evening.  Stress stimulates its secretion,  whereas cortisol acting via negative feedback suppresses its release.  1. Mechanism of action: ACTH binds to receptors on the surface of the adrenal cortex, thereby activating G protein–coupled processes that ultimately stimulate the rate-limiting step in the adrenocorticosteroid synthetic pathway (cholesterol to pregnenolone;  This pathway ends with the synthesis and release of the adrenocorticosteroids and the adrenal androgens. 2. Therapeutic uses:  1- corticotrophin mainly serve as a diagnostic tool for differentiating between primary adrenal insufficiency (Addison disease, associated with adrenal atrophy) and secondary adrenal insufficiency (caused by the inadequate secretion of ACTH by the pituitary).  Therapeutic corticotrophin preparations are extracts from the anterior pituitary of domestic animals or synthetic human ACTH.  ACTH is also used in the treatment of infantile spasm (West syndrome). 3. Adverse effects:  Short-term use of ACTH for diagnostic purposes is usually well tolerated.  With longer use, toxicities are similar to those of glucocorticoids and include hypertension, peripheral edema, hypokalemia, emotional disturbances, and increased risk of infection. Growth hormone (somatotropin)  Somatotropin is a large polypeptide that is released by the anterior pituitary in response to growth hormone (GH)-releasing hormone produced by the hypothalamus.  Secretion of GH is inhibited by another hypothalamic hormone, somatostatin.  GH is released in a pulsatile manner, with the highest levels occurring during sleep.  With increasing age, GH secretion decreases, accompanied by a decrease in lean muscle mass.  Somatotropin influences a wide variety of biochemical processes (for example, cell proliferation and bone growth are promoted).  Synthetic human GH (somatropin is produced using recombinant DNA technology.  1. Mechanism of action: Although many physiologic effects of GH are exerted directly at its targets, others are mediated through the somatomedins—insulin-like growth factors 1 and 2 (IGF-1 and IGF-2).  [Note: In acromegaly (a syndrome of excess GH due to hormone-secreting tumors), IGF-1 levels are consistently high, reflecting elevated GH.] 2. Therapeutic uses:  1- treatment of GH deficiency  2-growth failure in children  3-growth failure due to Prader-Willi syndrome  4- management of AIDS wasting syndrome  5- GH replacement in adults with confirmed GH deficiency.  [Note: GH administered to adults increases lean body mass, bone density, and skin thickness Somatropin is administered by subcutaneous or IM injection.  Although the half-life of GH is short (approximately 25 minutes), it induces the release of IGF-1 from the liver, which is responsible for subsequent GH-like action 3. Adverse effects:  1- pain at the injection site  2- edema  3- arthralgias  4- myalgias  5- flu-like symptoms,  6- increased risk of diabetes.  Somatropin should not be used in pediatric patients with closed epiphyses,  patients with diabetic retinopathy,  Prader-Willi syndrome with severe obese patient. C Somatostatin (Growth hormone-inhibiting hormone) Originally isolated from the hypothalamus, somatostatin is a small polypeptide that is also found in neurons throughout the body as well as in the intestine, stomach, and pancreas. In the pituitary, somatostatin binds to receptors that suppress GH and thyroid-stimulating hormone release.  Somatostatin not only inhibits the release of GH but also that of insulin, glucagon, and gastrin. Octreotide and lanreotide are synthetic analogs of somatostatin. There half-lifes are longer than that of the natural compound, and depot formulations are available, allowing for administration once every 4 weeks.  They have found use in the treatment of acromegaly and in diarrhea and flushing associated with carcinoid tumors.  An intravenous infusion of octreotide is also used for the treatment of bleeding esophageal varices. Adverse effects of octreotide  include diarrhea, abdominal pain, flatulence, nausea, and steatorrhea.  Gallbladder emptying is delayed, and asymptomatic cholesterol gallstones can occur with long-term treatment. Gonadotropin-releasing hormone  Pulsatile secretion of gonadotropin- releasing hormone (GnRH) from the hypothalamus is essential for the release of the gonadotropins follicles stimulating hormone (FSH) and luteinizing hormone (LH) from the anterior pituitary.  However, continuous administration of GnRH inhibits gonadotropin release through down-regulation of the GnRH receptors on the pituitary.  Leuprolide, Goserelin , Nafarelin, and Histrelin, synthetic GnRH analogs  Continuous administration of synthetic GnRH analogs, is effective in suppressing production of the gonadotropins  Suppression of gonadotropins, in turn, leads to reduced production of gonadal steroid hormones (androgens and estrogens).  Thus, these agents are effective in the treatment of prostate cancer, endometriosis, and precocious puberty.  In women, the GnRH analogs may cause hot flushes and sweating, as well as diminished libido, depression, and ovarian cysts.  Contraindicated in pregnancy and breast-feeding.  In men, they initially cause a rise in testosterone that can result in bone pain. Hot flushes, edema, gynecomastia, and diminished libido may also occur. Gonadotropins is a hormonally active medication for the treatment of fertility disturbances  1- Menotropins (also known as human menopausal gonadotropins or hMG) are obtained from the urine of postmenopausal women and contain both FSH and LH.  2- Urofollitropin is FSH obtained from postmenopausal women and is devoid of LH.  Follitropin alfa and Follitropin beta are human FSH products manufactured using recombinant DNA technology.  3- Human chorionic gonadotropin (hCG) is a placental hormone that is excreted in the urine of pregnant women.  The effects of hCG and choriogonadotropin alfa (made using recombinant DNA technology) are essentially identical to those of LH.  All of these hormones are injected via the IM or subcutaneous route..  Injection of hMG or FSH products over a period of 5 to 12 days causes ovarian follicular growth and maturation, and with subsequent injection of hCG, ovulation occurs.  Adverse effects include ovarian enlargement and possible ovarian hyperstimulation syndrome, which may be life threatening.  Multiple births are not uncommon Prolactin  Prolactin is a peptide hormone that is also secreted by the anterior pituitary.  Its primary function is to stimulate and maintain lactation.  In addition, it decreases sexual drive and reproductive function. Its secretion is inhibited by dopamine acting at D2 receptors agonist such as Bromocriptine and Cabergoline.. Bromocriptine and Cabergoline. D2 receptor agonists use in Hyperprolactinemia, which is associated with galactorrhea and hypogonadism,,  Both of these agents also find use in the treatment of pituitary microadenomas. Among their adverse effects are  nausea and vomiting  headache  psychiatric problems.  HORMONES OF THE POSTERIOR PITUITARY Oxytocin neuropeptide normally produced in the hypothalamus and released by the posterior pituitary. Hormone of love or “happy”!!!!! in humans it plays roles in behavior that include socialbonding reproduction, childbirth, and the period after childbirth. Oxytocin is used in obstetrics to 1- stimulate uterine contraction and induce labor. 2- Oxytocin also causes milk ejection by contracting the myoepithelial cells around the mammary alveoli.  Although toxicities are uncommon when the drug is used properly, hypertension, uterine rupture, water retention, and fetal death have been reported.  Its antidiuretic and pressor activities are much less pronounced than those of vasopressin. Vasopressin ( ADH )  is a nonapeptide synthesized in the hypothalamus.  play essential roles in the control of the body’s osmotic balance, blood pressure regulation, sodium homeostasis, and kidney functioning.  Vasopressin (antidiuretic hormone) is structurally related to oxytocin.  Vasopressin has both antidiuretic and vasopressor effects.  In the kidney, it binds to the V2 receptor to increase water permeability and reabsorption in the collecting tubules. Thus, the major use of vasopressin is to treat: 1- diabetes insipidus. 2- management of cardiac arrest 3- controlling bleeding due to esophageal varices.  Other effects of vasopressin are mediated by the V1 receptor, which is found in liver, vascular smooth muscle (where it causes constriction) The major toxicities of vasopressin are  water intoxication  hyponatremia.  Abdominal pain,  tremor,  vertigo. Desmopressin  an analog of vasopressin, has minimal activity at the V1 receptor, making it largely free of pressor effects.  This analog is longer acting than vasopressin and is preferred for the treatment of diabetes insipidus and nocturnal enuresis.  desmopressin may be administered intranasally or orally. [Note: The nasal spray should not be used for enuresis due to reports of seizures in children using this formulation.] Local irritation may occur with the nasal spray.