Drugs And The Endocrine System

Question 1

Name the endocrine systems?

Answer 1

Pituitary glands, thyroid glands, adrenal glands, ovaries, kidneys

Question 2

Explain thyroid disease

Answer 2

Affects the CNS, CVS, metabolic rate
Symptoms:
Hyperthyroidism 
-anxious, nervous, tremor, insomnia
-hypertension, tachycardia, palpitations
-low grade fever, intolerance to heat, increased appetite, weight loss

Hypothyroidism

• slow speech, lethargy, hyporeflexia
• hypotension, bradycardia, anaemia
• weight gain, low body temperature, intolerance to cold

Question 3

Define goitre

Answer 3

Swelling of the neck due to increased thyroid gland

Question 4

What happens in under active goitre?

Answer 4

1- not enough iodine, so insufficient T3/T4

2- disruption to the negative feedback

Question 5

What happens in an overactive thyroid?

Answer 5

1- activation of the TSH receptors by antibodies (Graves’ disease)
2. Increase in size and function of thyroid gland

Question 6

What happens in hyperthyroidism?

Answer 6

Graves’ disease autoimmune condition
Thyroid cells stimulated by auto-antibodies
Patients undergo remission
Treatment doesn’t cure but suppresses hyperthyroidism

Question 7

What is the treatment for hyperthyroidism?

Answer 7

Carbimazole or propylthiouracil
Limit iodine intake
Long term treatment: surgery or radioactive
Iodined replacement therapy “block and replace”

UK: propylthiouracil reserved for patients who are intolerable to carbomazole

Question 8

How does carbimazole work?

Answer 8

It inhibits the synthesis of thyroxine
Used for 4-6 weeks
Initially take 15-40mg daily until euthyroid the reduced dose

It’s absorbed through the gut , converted in the liver to its active form
Excreted via urine
Short 1/2 life

Active form is methimazole, accumulates in the thyroid gland agranulocytosis- bone marrow suppression presents as sore throat

Question 9

What are the side effects of carbimazole?

Answer 9

Nausea
Allergic rash/ itching
Agranulocytosis 
Insomnia 
Can transfer across placenta and in breast milk resulting in neonatal hypothyroidism

Question 10

Explain hypothyroidism

Answer 10

Patients require thyroxine substitute (T4) If severe administer T3 via IV
T3 much lower half life-balance blood level

Question 11

What drugs are used for hypothyroidism?

Answer 11

Oral thyroxine/ levothyroxine t4

IV Triiodothyronine T3

Question 12

Why is calcium needed in the body?

Answer 12

Calcium is the main hormone for remodelling bones

The parathyroid hormone promotes calcium absorption from the kidneys

Calcitonin (C cells) inhibits osteoclasts and reabsorption from the kidneys and so reduce calcium levels

Calcitriol (vitamin d3) increases calcium levels by increasing bone mobilisation and increase reabsorption from the gut

Question 13

What are the causes do hypocalcaemia?

Answer 13

Inadequate calcium intake
Deficiency in PTH or lack of vitamin d3
Renal problems

Question 14

What are the symptoms of hypocalcaemia?

Answer 14

Neuromuscular problems
Muscle cramps
Paraesthesia in extremities
Over time- mental deficiency 
Fits
Cataracts

Question 15

What are the treatments for hypocalcaemia?

Answer 15

Calcium glucoronate IV infusion

Ergocalciferol (vitamin d)- can only be sued if kidney function is not compromised- or calcitriol

Question 16

Why does hypercalcaemia need urgent attention?

Answer 16

Caused problems with the kidneys(stones), renal failure
Muscle problems- cardiac arrest
(Problems only last 2 days MAX)

Question 17

What are the treatments for hypercalcaemia?

Answer 17

Bishops phoneys and calcitonin

Question 18

Explain the use of biphosphonates.

Answer 18

Used to treat osteoporosis
Oral administration
AA slows rate of bone growth and turnover so prevents calcium loss from bones
Patient must not eat within1/2 hour of taking the medication, as food prevents proper absorption

Question 19

What are the side effects of biphosphonates?

Answer 19

Abdominal pain
GI disturbance
Oesophageal problems

Question 20

Explain use of calcitonin.

Answer 20

Usually from salmon-salmontonin
Expensive 
Short life
Ineffective with continuous use
Nasal spray or SC or IM

Question 21

Explain steroids in the body

Answer 21

Hormones
Can be given synthetically to treat for endocrine dysfunction or immune disorders
Most synthetic drugs have minercorticoid and glucocorticoid activity

Question 22

What does glucocorticoids do in the body?

Answer 22

Cortisol or hydrocortisone increase glucose mobilisation (gluconeogenesis)

Question 23

What does minieralocorticoid do in the body?

Answer 23

Aldosterone increase sodium retention and thus h20 retention, and potassium loss in DCT of the kidney nephron

Question 24

Where is steroids secreted from?

Answer 24

Cortex of adrenal glands

Question 25

Which drug is used to treat adrenal insufficiency?

Answer 25

Fludrocortisone

Question 26

Use of glucocorticoids?

Answer 26

Administered orally Metabolised in liver Used topically for eczema (h45 cream) Given low does orally for Addison's disease/ crisis-adrenal insufficiency Higher dose for the reduction of information following acute allergy

Question 27

What are the four types of glucocorticoids?

Answer 27

Prednisolone- orally, acute asthma attack Methylprednisolone- oral or parenterlly, not via GI tract, prevent rejection of transplant Dexanethasone- orally or parenterally, high anti inflammatory action, treat cerebral oedema Beclametasone- inhalation(brown inhaler), treat asthma

Question 28

What are the effects of oral glucocorticoids?

Answer 28

Hydrocortisone- low dose few adverse effects. High dose both glucocorticoid and minieralocorticoid effects Dexamethasone: glucocorticoid systematic effect Topical therapy minimised effects ``` Cushingoid features Oral thrush Hoarseness Psychiatric reactions Risk of chicken pox ```

Question 29

What is the withdrawal plan?

Answer 29

``` Gradual, If sudden can disrupt the negative feedback mechanism of ACTH/cortisol Low BP Low Glucose High potassium Low sodium Steroid card ```

Question 30

What are the types of reproductive steroids?

Answer 30

Oral contraceptives Hormone replacement therapy Oestrogens Progesterone

Question 31

Why use oral contraception?

Answer 31

Contains one or more female sex hormones, prevents conception. Blocks the normal process of ovulation and menstrual cycle

Question 32

What is the combined pill?

Answer 32

Inhibits ovulation Taken for 21 days, stopped for 7 Uterine bleeding during withdrawal period Absorbed lol orally Metabolised by liver Excreted in bile Can be prescribed for dysmenorrhea (regulate menstrual cycle) Reliable and reversible Reduces PMT High dose can be given as morning after pill up to 72 hours

Question 33

Adverse effects of the combined pill

Answer 33

``` MI and Strokes risk increase in smokers Hypertension Venous thromboembolytic disease - DVT/PE- high oestrogen preparation more risk p, increase clotting capacity of blood. Common with gestodene( new progesterone preparations) Links to carcinomas cervical/ breast Headaches ```

Question 34

What is the mini pill?

Answer 34

Progesterone only pill Alters the endometrium and cervical mucus to prevent implantation Inhibits ovulation in 40% of women Medroxyprogesterone- injection lasts 3 months or orally

Question 35

What are the effects of the mini pill?

Answer 35

Nausea Vomiting Breast discomfort

Question 36

What are the drug are the drug reaction?

Answer 36

Both combined pill and mini pill interact with hepatic enzyme inducers causing an increase in metabolism Some antibiotics also have similar effect (amoxycillin, ampicillin, doxycycline) reduce the effectiveness

Question 37

When is HRT used?

Answer 37

Post menopausal women Decrease in oestrogen levels and increase in LH/FSH Cessation of ovulation

Question 38

What risks are involved in HRT?

Answer 38

CVD Oestrogen levels in pills Osteoporosis

Question 39

What does HRT treat?

Answer 39

Symptoms Daily dose orally: oestrogens, oestrodiols Flushes, long term use- breast cancer

Question 40

What are the hormone modulators?

Answer 40

Tamoxifen-treat breast cancer, prophylaxis in high risk patients Oestrogen receptor antagonist reduce oestrogen levels Clomiphene- fertility treatment, oestrogen antagonist, inhibits the negative feedback if FSH/LH, can result in multiple births Somatatrophin-analogue of hGH, short stature children, turners syndrome or after pituitary surgery. IM OR SC. insulin resistance. Swelling, join pain, headaches Oxytocin-PP- induce labour. Reduce post-Parton haemorrhage

Question 41

How is the endocrine system managed?

Answer 41

Hormones