Drugs and the Endocrine System Flashcards
Thyroid disease, reproductive steroids, corticostercoids, pituitary hormones, calcium metabolism, osteoporosis and insulin are all related to which system?
The endocrine system
Hormones have widespread and diverse effects. What implications does this have for the management of endocrine disorders?
They are difficult to treat
1 in 13 people have issues with me. I can be hyper or hypo and I am related to T3 and T4. What am I?
Thyroid disease
The CNS, CV system and metabolic rate are all affected by which hormone disease?
Thyroid disease
What disease is linked to slow speak, lethargy, hyporeflexia (CNS), hypotension, bradycardia, anemia (CV), weight gain, low body temperature and intolerance to cold?
HYPOthyroidism
What is goitre?
A massive, noticeable thyroid gland
Do people with overactive or underactive thyroid get goitre?
Both.
In underactive this is because a lack of iodine leads to insufficient T3/T4, negative feedback is disrupted so it becomes bigger to try and compensate.
In overactive, antibodies are produced that activate TSH, which increases the size and function of the gland
What is Graves’ disease?
The most common form of hyperthyroidism.
Where antibodies stimulate thyroid cells.
What drugs can we use to treat hyperthyroidism?
Carbimazole and propylthiouracil
Before medical treatment, what can a patient try and do to regulate hyperthyroid issues?
Limit iodine (salt) intake - as this is used to produce thyroxine.
Which drug is taken to inhibit the synthesis of thyroxine, is absorbed at the gut to be converted at the liver to active form, is excreted in the urine and has a short 1/2 life?
Carbimazole
If a pregnant woman is taking Carbimazole, what are the potential side effects?
It could cross the placenta/into breast milk causing neonatal hypothyroidism
What are possible side effects of carbimazole?
Nausea, allergic rash, agranulocytosis, insomnia
As part of what type of treatment/method is carbimazole given?
Block and Replace.
Lots is taken at first, then the dosage is reduced so some thyroxine can be produced - but lack of thyroxine is replaced with synthetic thyroxine
How long does it take carbimazole to become effective?
4-6 weeks. It cannot get rid of thyroxine that has already been produced, it can only stop new thyroxine being produced.
For what condition is levothyroxine or triiodothyronine prescribed? And what are they substituting?
HYPOthyroidism
LevO = T4
TriiO = T3 (for more severe)
Lithium (depression) and amiodarone (anti arrhythmic) drugs can cause what type of hormone disease?
Hypothyroidism
When would we inject radioactive iodine into a patient?
If someone is severely hyperthyroid. The iodine will collect in the thyroid gland and the radioactive isotope will kill off tissue. This is the last step before resorting to surgery.
What does carbimazole target?
The thyroid gland. It stops it producing thyroxine (T4).
What is levothryoxine used to replace?
T4, thyroxine
What is triiodothyronine used to replace?
T3. This would be used in cases where there has been a dramatic loss of thyroxine, as T3 gives a much quicker response than T4.
What can a patient take to reduce the secondary EFFECTS of too much thyroxin?
Beta-blockers. They dampen the sympathetic nervous system.
Which hormone promotes Calcium reabsorption from the kidney?
Parathyroid hormone
What does calcitonin inhibit?
Osteoclasts and reabsorption from the kidney, resulting in decreased calcium plasma levels
BECAUSE less calcium comes back out of the kidney
tonin = tone = decrease
What does calcitriol (vitamin D3) do?
It increases calcium levels in the plasma by increasing bone mobilisation and reabsorption from the gut
What disease is caused by inadequate calcium intake, deficiency in parathyroid hormone/lack of vitamin D and renal problems?
HYPOcalcaemia
If someone had neuromuscular problems, muscle cramps and later mental deficiency, fits or cataracts, what might they have?
HYPOcalcaemia
When would we give someone Ergocalciferol (vitamin D) and which groups of patients can we not give it to?
People with hypocalcaemia.
We cannot give this drug to people with compromised kidney function however.
(more complicated name - can’t give to compromised patients)
Who can we give calcium glucoronate (as an I.V. infusion) or calcitriol?
Anyone with hypocalcaemia
What disease can cause problems with kidney stones/renal failure and muscle problems/cardiac arrest, that needs urgent attention?
HYPERcalcaemia
What drugs can we use to treat hypercalcaemia?
Calcitonin and Biphosphonates
Think about how calcitonin inhibits calcium reabsorption from the kidney, so it will reduce levels in the blood
What drug is expensive (from salmon) and has a very short 1/2 life, and becomes ineffective with continued use?
Calcitonin
How can calcitonin be administered?
By nasal spray or subcutaneous/IM injection
What is alendronic acid an example of? It is used to slow the rate of bone growth and turnover to prevent calcium loss from bones. It is used to treat hypercalcaemia/osteoporosis.
A biphosphonate.
What hypercalcaemic drugs have side effects of abdominal pain, GI disturbances such as oesophageal problems and will not be absorbed properly if the patient eats within half an hour of consumption?
Biphosphonates
Steroids are artificial what?
Hormones
What hormones do corticosteroids emulate?
Hormones from the cortex of the adrenal gland
What are mineralocorticoids and glucocorticoids examples of?
Hormones
What do mineralocorticoids affect?
Electrolyte balance
What does fludrocortisone treat?
Adrenal insufficiency - lack of mineralocorticoid production
What type of hormone increases glucose mobilisation and resistance to stress, and decreases white blood cells?
Glucocorticoids
What hormones beginning with M and G can be given synthetically to people with endocrine dysfunction or autoimmune disorders?
Mineralocorticoids and Glucocorticoids
If a person has low blood pressure and low glucose, what corticoid are they likely to be low on?
Glucocorticoid
What synthetic hormone or steroid is used to treat Addisons’ disease/crisis-adrenal insufficiencey (as a low oral dose), or to reduce inflammation during an acute allergy (as a higher topical dose e.g. eczema)
Hydrocortisone
Where is hydrocortisone metabolised after oral administration?
The liver
When administering hydrocortisone for inflammation you start at a high dose. At which point should this be reduced?
When the inflammation is supressed
What glucocorticoid is used for acute asthma attacks that is given orally, is 5x more potent than hydrocortisone and has less mineralcorticoid activity?
P
Prednisolone
What glucocorticoid is used to prevent rejection in transplant patients that is given parenterally?
Methylprednisolone
I’d want meth if I had to have a transplant op
What glucocorticoid is administered orally or parenterally, has high anti-inflammatory action and is used to treat cerebral oedema?
It is 20x more potent than hydrocortisone.
Dexamethasone
Dexter - brainy - cerebral
What glucocorticoid is used to treat asthma in a brown inhaler?
Beclametasone
What route of administration minimises systemic adverse effects of steroids/glucocorticoids?
Topical
If hydrocortisone is given in a high dose, what effect will it have other than glucocorticoid effects?
Mineralcorticoid
What specific drug types can result in a buffalo hump, hypertension, muscle wasting, osteoporosis, moon face, increased abdominal fat, thinning of the skin, cushioned features and poor wound healing?
ORAL glucocorticoids
What specific drug types can cause local immunosuppression resulting in oral thrush/candida albicans, and have local effects on the vocal chords causing dysphonia/hoarseness?
INHALED glucocorticosteroids
What can reduce unwanted side-effects of inhaled glucocorticoids?
Using a spacer device or rinsing mouth after inhaler use
When withdrawing gluco/mineralcorticoid treatment what is important?
It must be gradual
What happens if the withdrawal of G or M steroids is not gradual?
It may disrupt the feedback mechanism of ACTH/cortisol sending a patient into an Addisonian crisis = low BP, low glucose, high pottasium and low sodium
What types of steroid are oral contraceptives and hormone replacement therapy (treats osteoporosis)?
Reproductive Steroids
What are oestriol, oestradiol and oesterone?
Synthetic oestrogen
What is progestin?
Synthetic progesterone
What type of oral contraceptive inhibits ovulation?
The combined pill.
It has artificial oestrogen and progesterone, which sends signals to the AP, inhibiting FSH and LH therefore inhibiting ovulation
What can be prescribed for dysmenorrhoea, is absorbed orally, metabolised by the liver and excreted in bile?
Combined Pill
What can be used in a high dose, up to 72 hours as a morning after pill?
Combined Pill
What steroid drug can cause MI and strokes (particularly in smokers), hypertension, cervical/breast cancer, headaches and venous thromboembolytic disease?
Combined pill
VTD is due to high oestrogen/progesterone = increased clotting capacity
How does the mini pill work?
What hormone does it use?
It uses progesterone and is taken every day.
This pill alters endometrium and cervical mucus to prevent implantation and sometimes inhibits ovulation
What contraceptive is given by injection every 3 months?
Medroxyprogesterone
What are the side effects of the mini pill and medroxyprogesterone?
Nausea, vomiting and breast discomfort
What can the combined and mini pill interact with that may increase drug metabolism, thereby reducing its effectiveness?
Hepatic enzyme inducers and antibiotics
What drug is used to treat a decrease in oestrogen levels in post menopausal women, who have increased LH and FSH and potentially osteoporosis?
HRT
What are the common side effects of HRT?
Cardiovascular disease, increased risk of endometrial/breast cancer and thromboembolytic disorders
What hormone modulator is used to treat breast cancer? It decreases oestrogen levels by binding to oestrogen receptors
Tamoxifen
What hormone modulator is used to stimulate ovulation as a fertility treatment, by binding to oestrogen receptors in the hypothalamus to inhibit negative feedback of FSH/LH?
Clomiphene
It can result in multiple births however
What hormone modulator is an analogue of hGH, is administered parentally for short children, Turner’s syndrome or after pituitary surgery?
Somatatrophin
What are the adverse effects of somatatrophin?
Insulin resistance, swelling of injection site, joint pain and headaches
Prostaglandins are used to induce labour/abortion and reduce post-partum haemorrhage.
What hormone is it affecting?
Oxytocin-Peptide hormone
