drugs and the endocrine system Flashcards
what are endocrine diseases?
hormones involved - wide spread and diverse effects on body
hormone deficiency
hormone over activity
what is thyroid disease and what does it affect?
can be hypothyroidism or hyperthyroidism
can affect CNS, metabolism and CV system
what are the symptoms of hypothyroidism?
slow speech lethargy hypotension bradycardia anaemia weight gain low body temp intolerant to cold (everything depressed - under active)
what are the symptoms of hyperthyroidism?
anxiety nervousness hypertension tachycardia low grade fever inholerant to heat weight loss (everything activated - over active)
is a goitre present in hypo or hyperthyroidism?
both
what causes a goitre in hypothyroidism?
not enough iodine so insufficient T3 and T4
disrupts negative feedback
no TSH production
what causes a goitre in hyperthyroidism?
activation of TSH receptors by antibodies
increase in size and function of thyroid gland
what causes hyperthyroidism?
thyroid cells stimulated by auto-antibodies (autoimmune disease such as graves disease)
can treatment cure hyperthyroidism?
no but can supress
give two examples of drugs used to treat hyperthyroidism
Carbimazole
Propylthiouracil
(plus limited iodine intake)
what treatments other an drugs can be used to treat hyperthyroidism?
surgery or radioactive iodine - block and replace therapy
what does the drug carbimazole do to treat hyperthyroidism?
blocks T3 and T4 production - this is then replaced in small amounts
interferes with synthesis of thyroxine
(short half life)
where is carbimazole absorbed, activated and excreted?
absorbed in gut
activated in liver
excreted in urine
what are the side effects of carbimazole?
nausea
rash
agranulocytosis - deficiency of granulocytes in blood causing increased risk of infection
can cross placenta causing neonatal hyperthyroidism
how is hypothyroidism treated?
with thyroxine substitute
name two thyroxine substitutes
levothyroxine T4
triiodothyronine T3 - severe cases (IV)
which thyroxine substitute has a shorter half life and balances blood level?
triiodothyronine T3
name two drugs which can cause hypothyroidism
lithium (depression)
amiodarone (antiarrhythmic)
which hormone promotes reabsorption of Ca2+ from the kidneys?
parathyroid hormone
what does calcitonin (c-cells) do?
reduces Ca2+ - inhibits osteoclasts and reabsorption of Ca2+ from kidneys
what does calcitriol (vit D3) do?
increases Ca2+ - increase bone mobilisation and increase reabsorption in gut
what is hypocalcaemia?
not enough calcium
what are the symptoms of hypocalcaemia?
neuromuscular probs muscle cramps mental probs seizures cataracts
what are the causes of hypocalcaemia?
reduced Ca2+ intake (diet)
deficiency in PTH
lack of vit D (needed for absorption of Ca2+)
renal probs
what is used to treat hypocalcaemia due to vit D deficiency?
ergocalciferol (vit D) - good kidney function needed
calcitriol