Medications and the Endocrine System

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Medications and the Endocrine System

• RN2 Medication Course
• School of Nursing Health Studies
• Victoria University

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Endocrine System

• Consists of ductless glands
• Produce hormones that regulate and control the
  metabolic activities of the body, thus
  maintaining homeostasis
• Participates in the regulation of
• Digestion, use and storage of nutrients
• Growth and development
• Electrolyte and water metabolism
• Reproductive functions

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Endocrine System Overview

• The nervous system coordinates rapid and precise
  responses to stimuli using action potentials
• The endocrine system maintains homeostasis and
  long-term control using chemical signals
  (hormones)
• The endocrine system works in parallel with the
  nervous system to control growth and maturation
  along with homeostasis.

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Endocrine System Overview

• A gland is a group of cells that produces and
  secretes chemicals in response to a stimulus
• Exocrine glands, e.g. sweat and salivary glands,
  release secretions in the skin or inside the
  mouth via ducts (ex outside)
• Endocrine glands release more than 20 major
  hormones directly into the bloodstream where they
  can be transported to cells in other parts of the
  body (endo inside)

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Endocrine System Overview

1. Hormone enters blood extracellular fluid
2. Arrives at target cell which has a protein
   membrane receptor. Hormone (key) will only
   enter unlock a target cell matched to that
   hormone
3. Entry of hormone then alters the cells function

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Major Endocrine Glands

• Pineal Gland
• Hypothalamus
• Pituitary Gland
• Anterior
• Posterior
• Thyroid Gland
• Parathyroid Glands

• Adrenal Glands
• Cortex
• Medulla
• Thymus Gland
• Pancreas
• Gonads
• Ovaries
• Testes

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Endocrine control

• Feedback Mechanisms
• Controls and prevents the over production and
  underproduction of a hormone thus ensuring
  homeostasis
• Conditions may occur due to
• A gland enlarging or shrinking in size resulting
  in either
• Hyper-secretion or
• Hypo-secretion

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Revision Major endocrine conditions
Endocrine Gland Hormones Endocrine Disorders Endocrine Disorders
Endocrine Gland Hormones Hyper Hypo
Anterior Pituitary Growth Hormone Gigantism, acromegaly Dwarfism
Thyroid Thyroxine (T4) Triodothronine (T3) Thyrotoxicosis Goitre Exopthalmos Hypothroidism Cretinism Myxoedema Goitre
Parathyroid Parathormone Osteoporosis Kidney stones Kidney stones Tetany
Adrenal Cortex Glucacorticoids Cushings syndrome Addisons disease
Adrenal Medulla Epinephrine Norepinephrine Increased metabolism Hypertension
Pancreatic Islets Insulin Diabetes mellitus
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Endocrine control

• Hypothalamus Pituitary.
• Together they control many endocrine functions
• Hypothalamus
• When stimulated by feedback produces releasing
  factors (RF) that stimulates the pituitary to
  release hormones
• Pituitary gland
• The master gland of the body

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Pituitary Gland

• The hypothalamus exerts hormonal control
• Pituitary gland
• Size of a grape
• Hangs by a stalk from the hypothalamus
• Protected by the sphenoid bone
• Has two functional lobes
• Anterior pituitary glandular tissue
• Posterior pituitary nervous tissue

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Hormones of the Anterior Pituitary
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Growth hormone

• General metabolic hormone
• Major effects are directed to growth of skeletal
  muscles and long bones
• Causes amino acids to be built into proteins
• Causes fats to be broken down for a source of
  energy

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Anterior Pituitary disorders

• Hyperpituitarism Increased Growth Hormone
• Gigantism - during childhood or
• Acromegaly - adulthood
• Usually due to a slow growing adenoma
• Skeletal overgrowth
• Treatment
• Surgery
• Chemotherapy
• Bromocryptine (Parlodel)

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Hyper secretion of Growth hormone Gigantism
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Hypersecretion of Growth hormone Acromegaly
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Acromegaly
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Removal of the Pituitary Gland
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Anterior Pituitary disorders

• Hypopituitarism Insufficient supply of hormones
• metabolic dysfunction
• sexual immaturity
• growth retardation - dwarfism
• Due to congennital causes, trauma, a tumour of
  the pituitary or hypothalamus
• Replacement of hormones
• Corticosteroids, thyroid sex hormones
• Growth hormone
• Somatotropin (Genotropin, Humatrope)

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Pituitary Dwarfism
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Posterior Pituitary Hormones

• Oxytocin stimulates contractions of the uterus
  milk let-down
• Antidiuretic hormone (ADH)
• Can inhibit urine production
• In large amounts, causes vasoconstriction leading
  to increased blood pressure (vasopressin)

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Posterior Pituitary Diabetes Insipidus

• Deficiency of Anti Diuretic Hormone (ADH)
• Causes congenital, surgery, trauma, infection
• Replacement
• Vasopressin
• Pitressin IMI/S.C/ intranasal
• Desmopressin
• Minirin nasal spray
• Minirin, Octostim
• injection IV/IMI

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Thyroid disorders
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Thyroid Gland

• Two lobes a connecting isthmus
• Controlled by hypothalamus pituitary gland
• Produces two hormones
• Thyroid hormone Calcitonin
• Thyroid Hormone
• Major metabolic hormone
• Requires iodine
• Composed of two hormones
• Thyroxine (T4) precursor
• Triiodothyronine (T3) active hormone

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THYROID DISORDERS

• Hyperthyroidism
• An over production of thyroxine causing a
  metabolic imbalance causing thyrotoxicosis
• Hypothyroidism
• an underproduction of thyroxine leading to a
  slowing of the metabolic process causing
  myxoedema
• Euthyroid State Normal thyroid hormone
  production

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Hyperthyroidism versus Hypothyroidism

• Tachycardia
• Pyrexia
• Hyperactivity
• Anxiety
• Moist skin
• Exophthalmos
• Possible goitre
• Weight loss
• Increased appetite

• Bradycardia
• Hypopyrexia
• Hypoactivity
• Fatigue
• Dry Skin
• Hair Loss
• Oedema
• Weight Gain
• Poor Memory

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Enlarged thyroid - GOITRE

• Euthyroid thyroid follicles/cysts
• Iodine deficiency
• Toxic overproduction of thryoxin
• Signs Symptoms
• neck enlargement
• dysphagia
• respiratory distress
• Treatment depends on cause

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Hyperthyroidism

• Hyperthyroidism (Graves Disease)
• Multi system autoimmune disorder characterised by
  pronounced hyperthyroidism, and usually
  associated with an enlarged thyroid gland.
• Origin is unknown but may be familial.
• 5 times more common in women than in men
• Can arise after an infection or physical or
  emotional stress.
• Usually occurs between 30 to 60 years of age
• Treatment
• Antithyroid agents
• Surgery

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Exopthalmos

• This is an abnormal condition marked by
  protrusion of the eyeballs.

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Anti-Thyroid Medications

• Carbimazole (Neo-Mercazole)
• Decreases thyroid hormone synthesis. High dose
  initially then decreased to maintenance
• Propylthiouracil
• As above but also prevents conversion of T4 to T3
• Sodium Iodide (1311) (Radioactive)
• used to reduce the production of thyroid hormones
  by destroying thyroid cells.
• Generally used in patients who are not good
  surgical candidates (cardiac dysfunctions,
  elderly debilitated)
• Specific nursing considerations are required

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Hypothyroidism

• Decreased activity of the thyroid gland
• Caused by
• Congenital (cretinism)
• Surgical removal
• Decrease of thyroid stimulating hormone
  (Myxoedema)
• Atrophy of the thyroid gland

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Hashimotos disease

• An auto immune thyroid disorder characterised by
  the production of antibodies in response to
  thyroid antigens.
• The disease shows a marked hereditary pattern.
• It is 20 times more common in women than in men
• The goitre is usually asymptomatic.
• Treatment thyroxin
• Prognosis good with treatment

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Myxoedema

• Signs Symptoms
• Weight gain
• Mental and physical lethargy
• Dryness of the skin
• Constipation
• Slow metabolism
• Coma / death

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Hypothryoidism
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Myxoedema
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Thyroid Medications

• Thyroxine
• Slow in onset but long-acting
• Usually for maintenance therapy
• Liothyronine (Tertroxin)
• Rapidly absorbed from GIT short-acting
• Usually used for emergency therapy.
• Adverse Effects
• Usually decrease with time
• Tremor, headache tachycardia Arrhythmias
• GIT disturbances, weight loss

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Thyroxin

• Oroxine, Eutrosig
• Correct storage use essential
• Unstable in light, heat, humidity
• Keep in original packaging
• Recommended to keep in fridge
• Check expiry date
• Bioavailability varies from 40-80
• Take on an empty stomach 30-60 mins pre-breakfast
• Or in the evening pre bed on an empty stomach
• Or with breakfast but dose will be higher must
  be taken the same way each day
• Decreased absorption with iron, antacids,
  calcium, milk, soy etc

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Thyroxin

• Half-life
• 6-7 days Euthyroid
• 3-4 days Hyperthyroid
• gt7 days Hypothyroid
• Duration of action 7-21 days
• Takes 3-4 weeks for full therapeutic effect
• Levels every 6 weeks initially then 6 monthly
  when stable
• Interactions
• Increased effect - warfarin, phenobarb
• Decreased effect steroids, digoxin,
  hypoglycaemics

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Parathyroid Glands

• Tiny masses on the posterior of the thyroid
• Secrete parathyroid hormone
• Raise calcium levels in the blood
• Stimulate osteoclasts to remove calcium from bone
• Stimulate the kidneys and intestine to absorb
  more calcium

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Calcitonin

• Produced by C cells(parafollicular) in the
  thyroid gland
• Decreases blood calcium levels by causing its
  deposition on bone
• Antagonistic to parathyroid hormone

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Parathyroid disorders

• Hyperparathyroidism an excess production of
  parathyroid hormone which may be due to tumours,
  hereditary factors or secondary to renal disease.
  
• Causes bone decalcification and renal calculi due
  to an hypercalcemia
• Treatment
• Calcitonin SC or IMI
• Surgery

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Parathyroid disorders

• Hypoparathyroidism leads to a hypocalcaemia
  causing neuromuscular excitability, cardiac
  irregularities, and digital paraesthesia
• Acute IV calcium
• Replacement Calcium Supplements, Vit D

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Steroid Therapy

• RN2 Medication Course
• School of Nursing Health Services
• Victoria University

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Objectives

• State the functions of natural steroids
• List the indications for steroid therapy
• Outline the side effects of steroid therapy
• Explain why steroid therapy must be gradually
  withdrawn
• Discuss how side effects may be minimised with
  inhaled, topical and oral steroid therapy
• Describe the patient education required for a
  client on steroid therapy

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Adrenal glands

• The medulla secretes
• Adrenaline
• epinephrine
• Noradrenaline
• Norepinephrine
• The cortex secretes
• Glucocorticoids
• Mineralocorticoids
• Androgens

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Corticosteroids

• Glucocorticoids
• or corticosteroids or steroids
• Metabolic, anti-inflammatory immunosupressant
  effects
• Mineralocorticoids (principally aldosterone)
• Electrolyte fluid balance via
• Sodium water retention
• Potassium excretion
• Androgens
• Development of sex organs
• Regulation of reproduction

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Natural Corticosteroids

• 1. Resistance to stress
• Work synergistically with adrenaline to maintain
  homeostasis
• Potentiate the vasoconstriction action of
  nor-adrenaline, therefore assist to increase BP
• Natural surges during stress e.g. infection,
  surgery

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Natural Corticosteroids

• 2. Metabolic effects
• Increase blood glucose by
• Gluconeogenesis in liver from fats AA
• Increases plasma Amino Acids
• Mobilises fatty acids for energy
• Decreases cell uptake of glucose

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Natural Corticosteroids

• 3. Anti-inflammatory
• Decreases inflammatory mediators
• Decreases movement of neutrophils
• ?antigen/antibody response
• 4. Immunosupression
• Decreases thymic activity
• Decreases lymphocyte activity

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Natural Corticosteroids

• No major stores in body, produced when required
  i.e. stimulated by ACTH from anterior pituitary
• Produced from cholesterol
• Cortisone is hydroxylated in the liver to
  prednisone and then activated to prednisilone
• Blood cortisol levels kept within very narrow
  limits
• The normal effects of cortisol do not produce the
  effect of steroid drugs used at high doses/for
  prolonged periods

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Corticosteroids Uses

• Replacement therapy
• in conditions where adrenal insufficiency has
  occurred.
• Anti-inflammatory/allergic action
• Asthma, hay fever, eczema
• Inflammatory bowel disease, Lupus, Rheumatoid
  Arthritis
• Suppression of immunity
• Prevent rejection of organ transplants
• Anti-tumour action
• Anti-lymphocytic action Lymphomas, leukaemias
• Decrease tumour size, decrease cerebral oedema

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Adverse effects of therapy

• Effects carbohydrate metabolism
• Increased blood glucose
• Mainly an issue in diabetics
• Decrease sensitivity to insulin
• Electrolyte fluid balance
• Steroids cross react with aldosterone receptors
  in kidney and lead to the retention of sodium,
  water and excretion of potassium
• Hypertension
• Oedema
• Hypokalaemia

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Adverse effects of therapy

• Protein calcium changes
• Muscle weakness wasting
• Delayed wound healing
• Osteoporosis Bone thinning
• Decreased bone production
• ?Calcium absorption from gut and ? excretion in
  kidneys
• Osteoporosis if prolonged therapy
• Inhibits growth in children

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Adverse effects of therapy

• Suppression of inflammation immunity
• Suppression of immune tissues cells
• ?inflammatory response
• Masks signs of infection
• Other
• Gastric ulceration
• Increased gastric acidity
• Cataracts glaucoma
• Psychological effects
• Euphoria, insomnia, depression, psychosis

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Adverse effects of therapy

• Redistribution of fat
• Buffalo hump, moon face
• Skin changes
• Skin thinning
• Susceptible to bruising
• Striae
• Tendency to acne
• Hirsuitism

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Hirsutism
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Corticosteroids

• Adverse Reactions
• Generally due to prolonged use
• Cushings syndrome
• To maximise benefits and limit side effects
  steroids should be ordered at lowest dose
  possible, for as short a time as possible to be
  effective

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Greenstein 2000 p 207
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Cushings Syndrome
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Adverse effects of therapy

• Atrophy of adrenal cortex
• Doses gt5mg/day/prolonged
• Suppression of stress responses
• Adrenal gland unable to respond with increased
  cortisol levels as cortex suppressed
• Leads to Addisons Crisis

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Synthetic Steroids

• Available as
• inhaled steroids
• nasal sprays
• metered-dose inhalers
• rectal
• topical
• oral (pills or syrups)
• injections for
• IMI
• IVI
• intraarticular

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Topical Steroids

• Anti-inflammatory drugs applied to the site where
  response required.
• Usually prescribed to treat inflammatory skin
  conditions
• Fewer adverse effects than from oral or parental
  administration.
• Available as
• Lotions, creams, ointments, gel

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Topical Steroids

• How they work
• Suppress inflammatory response at the site of
  application.
• Minimally absorbed by normal skin
• Absorption dependant on the site of application
  (thickness of skin)
• Absorption increased where the natural barriers
  have been compromised
• inflammed skin
• wound sites

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Topical Steroids

• Side effects
• Dry, irritated skin
• Erythema
• Unusual hair growth
• Atrophy of skin
• Striae
• Tendency to bacterial fungal infections
• Systemic effects may occur after prolonged use

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Topical steroids Classified according to potency

• Mild
• Hydrocortisone 0.5-1
• Never use anything stronger than hydrocortisone
  on the face
• Egocort, Dermaid, Anusol, Cortaid, Hydrocortone
• Potent
• Betamethasone 0.02, 0.05 1
• Betnovate, Celestone, Diprosone
• Mometasone 0.1
• Elocon, Novasone
• Triamcinolone
• Aristocort

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Topical Steroids

• Usually only daily or twice day applications
  ordered
• Wear gloves to apply
• Thin smear only
• Wash hands post easily absorbed through skin
• Do not apply occlusive dressing unless ordered
  increases absorption
• Should not be used alone when there is a
  bacterial/fungal infection as may cause spread of
  infection

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Inhaled Steroids

• Inhaled steroids are synthetic in origin.
• Generally prescribed as a long-term control
  medication, to be used daily.
• Act to reduce inflammation in either
• lungs (asthma) or
• nose (nasal allergies)
• makes them less sensitive and possibly decreases
  mucus production

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Inhaled Steroids

• Inhaled (MDI etc)
• Used primarily to treat and/or prevent lung
  inflammation (asthma)
• Nasally Inhaled Steroids
• Reduce inflammation form nasal allergies
• Beclomethasone Beconase, Vancenase, Vanceril,
  Fluticase Flovent, Flonase
• Triamcinolone Azmacort
• Common side effects
• Coughing, hoarseness, dry mouth, throat
  irritation, flushing, loss of taste or unpleasant
  taste.
• Thrush (causing discolouration of the tongue)
• Burning irritation inside the nose
• Headache, runny nose, sneezing, watery eyes,
  nosebleeds
• How could side effects be minimised?

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Parental steroids

• Intravenous
• Intramuscular
• Intra-articular
• Hydrocortisone
• Dexamethasone

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Synthetic Corticosteroids

• Similar to natural cortisol
• Regulation of cortisol occurs in the brain but
  brain is unable to tell difference between
  naturally occurring and synthetic medication
• Normal steroid circadian rhythm higher in the
  morning, reaches a peak after waking then falls
  slowly to low levels in the evening early
  phases of sleep
• Sustained high doses leads to adrenal suppression
• Dosage should be reduced gradually to allow the
  adrenal gland to recover and increase cortisol
  production at a normal level again

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Synthetic steroids

• Duration of action
• Short acting (8-12 hours)
• Cortisone
• Hydrocortisone
• Intermediate (1-3 days)
• Prednisone
• Prednisilone
• Long acting (2-3 days)
• Dexamethasone
• Betamethasone

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Comparison of Corticosteroid strengths
Drug Strength
Hydrocortisone Prednisone Prednisolone Methylprednisolone Dexamethasone Betamethasone 25 mg 5 mg 5 mg 4 mg 500 mcg 500 mcg
Representation of relative potencies of some
corticosteroids for equivalent anti-inflammatory
action
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Corticosteroids

• Readily absorbed
• 90 bound to plasma proteins
• Metabolized in liver body tissues
• Excreted in kidneys
• Prednisone vs Prednisolone
• Prednisone is an inactive drug which is
  metabolised by the liver, whereas prednisolone is
  active
• Clients with hepatic dysfunction must be given
  prednisolone.
• Dosage
• Usually commenced with lowest possible dose which
  is increased until improvement is achieved
• Under normal circumstances treatment does not
  extend longer than 4-6 weeks

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Addisons Crisis

• Any stress can increase requirements
• Natural cortisol production suppressed therefore
  body cannot supply the extra surge needed
• Addisons crisis shock-like state
• Collapse, vomiting, low BP
• Hydrocortisone IV
• IV fluids glucose
• Increased steroid dosage required for
• Infection, surgery, stress

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Tapering dosage

• When dose is to be discontinued, decrease
  gradually to enable adrenal cortex to produce
  cortisol
• It can take the adrenal cortex up to 2 years to
  recover from prolonged treatment
• Long term therapy ceased gradually over days,
  weeks, months to allow return of adrenal function
• Report any vomiting, weakness or fainting

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Oral Steroids

• Available as
• solution, syrup or tablet
• Commonly a form of prednisone.
• Prednisone, prednisolone, methylprednisolone
• Used both for short long term therapy
• Used to treat a multitude of diseases
• Asthma,
• Systemic lupus erythematosus (SLE)
• Prevention of transplant rejection
• And other inflammatory-based diseases

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Oral Steroids

• Steroid Burst
• A burst may last 2 to 7-days and not require a
  reducing dose or several weeks with a reducing
  dose ? steroid taper
• Common side effects include
• Loss of appetite, fluid retention, moodiness and
  stomach upset
• Routine Steroids
• Used in clients with chronic lung disease. Client
  usually under a pulmonologist or allergist

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Administration (oral)

• Simulate normal circadian rhythm to minimise
  adrenal suppression
• Avoid evening doses
• Administer mane or
• Mane (2/3 dose) and evening (1/3 dose)
• Give with food
• Alternate day dosing
• Minimises suppression
• Often in children to minimise growth suppression

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Interactions

• Effects increased by
• OCP, ketaconazole
• Effects decreased by
• Phenytoin, barbiturates, antacids
• Other
• Counteracts effects of oral hypoglycaemics
• Increases risk of gastric ulcer if NSAIDs
• Increased risk of digoxin toxicity (?K)
• Not given with live virus immunisations

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Client Education

• Take medication as ordered at the advised time
• Do not stop taking suddenly
• Medic alert bracelet if oral steroids (prolonged)
• Take with food to decrease gastric irritation
• Well balanced diet, adequate protein
• Decrease refined sugars
• Limit salt intake,
• Add foods high in potassium calcium
• Avoid alcohol, NSAIDs aspirin

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Client Education

• Eye check annually, alert dr - steroid use
• Keep skin well moisturised
• Routine exercise to minimise muscle wasting
• Avoid exposure to infections
• Especially varicella measles
• Annual flu immunisation
• Monitor
• Blood pressure
• BGL may need checking
• For inhaled
• Check technique, use spacer, rinse mouth

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Client Education

• Steroids used for treatment of conditions such as
  asthma are not the same as the anabolic steroids
  used illegally by athletes or in body-building.
• Corticosteroids do not affect the liver or cause
  sterility.