Graves Disease Flashcards
Symptoms of thyrotoxicosis (hyperthyroidism)
-CNS= fatigue, nervousness, anxiety, hyperactivity, poor concentration
-Thinning hair loss
-Eye soreness and grittiness
-Neck swelling
-Weak muscles and tremor
-Skin: heat intolerance, increased sweating
-Palpitations and shortness of breath
-Irregular periods, reduced fertility (women), reduced libido (men)
Consequences of an overactive thyroid
-Weight loss
-Osteoporosis (increased bone fractures)
-AF
-HF
-Blood clots
-Muscle weakness
-Mood changes (anxiety, irritability)
Causes of hyperactive thyroid
-Graves (autoimmune)
-Nodular thyroid disease
-Thyroiditis (inflammation)
=post-partum
=medication (amiodarone, lithium)
=unknown
What is Graves disease?
-Stimulating antibodies to thyroid gland stimulates excess production of thyroid hormones
-80% risk inherited/ genetic (50% have family history)
Tests for Graves disease
-Thyroid function test:
=Thyroid stimulating hormone (decreased)
=T4 increased
-T3 increased
-TSH receptor antibodies (TRAb) increased
-Scintigraphy scan (map of activity= dark)
Describe thyroid eye disease
-1/3 Graves disease
-Swelling/ inflammation behind the eyes
-Moderate or severe in only 5%
-More common in cigarette smokers x2/8
-Ophthalmopathy: proptosis (bulging eyes), eyelid retraction, lag, and swelling, conjunctivitis, conjunctival oedema, optic disc swelling, pain behind eyes, restriction of eye movements (severe), photophobia, excessive watering, redness, double vision, unexplained deterioration in visual acuity, globe subluxation. Risk of exposure keratopathy.
-Management: topical lubricants, steroids, hyperthyroid management
3 main treatment options for Graves Disease
-Tablets
=Carbimazole
=Propylthiouracil (PTU)
=Beta blockers (for symptom control- tremor and palpitations)
-Radioiodine (single capsule, taken up by thyroid gland)
-Surgery
=Typically reserved for when tablets or radioiodine ineffective or not possible
Pros and cons of treatment options
-Medication
=Possibility of coming off medication
=High risk of developing overactive thyroid gland again
-Definitive therapies (radioiodine, surgery)
=>70% chance of requiring lifelong thyroxine replacement (most within 2 years)
=Low risk of ever developing overactive thyroid again
Beta blockers for thyrotoxicosis
-Do not treat the overactive thyroid but help control symptoms until thyroid hormone levels normalise
-Typically propranolol
-Not suitable for people with asthma
Carbimazole and PTU for thyroid
-Thionamides
-Will reduce thyroid hormone levels within weeks
-Typically a 12 to 18 month course with clinic visits every 2-3 months initially (TRAB, TSH, fT4)
-Potential for long-term low-dose carbimazole to limit recurrence
Carbimazole side effects
-Generally well tolerated
-Rash 6%
-Liver injury 1 in 200
-Ver rare (1 in 300) large reduction in white blood cell count
=More likely older/ larger doses
=sore throat/fever= urgent blood test
Thionamides in pregnancy
-Carbimazole 2-4% risk birth defects
-PTU 2-3% risk birth defects (generally less severe)
-1:10000 risk liver failure adults with PTU
Recurrence rate Carbimazole
-High antibodies at start and end after 1 year: 50%
-Low: 30%
-High start and end 4 years: 90%
-Low:60%
Radioiodine treatment for thyroid
-Well tolerated, side effects rare
-Not suitable in pregnancy planned within 6 months
-Single capsule by mouth
-Destroys overactive tissue
-Thyroid hormone levels fall within 4 to 8 weeks
=78% become underactive and on levothyroxine
= 7% normal
=15% active at 1 year
Radioiodine risks
-Thyroid eye disease (prednisolone when mild)
-Occasional short-term increase in thyroid hormone levels (beta blocker)
-No evidence of increased cancer risk
-Avoiding effects of underactive thyroid: regular blood tests, ‘block and replace’ (replacing thyroid hormone with carbimazole)
-Observe radiation safety guidelines
