Medical management of Thyroid disease

In the Name of God, Most Gracious, Most Merciful

The history of man…

… is plagued by disease

Today …

We discuss …

THYROIDDISORDERS

THYROTOXICOSIS

MYXOEDEMA

CRETINISM

MEDICAL EMERGENCIES

THYROID DISEASE COMPLICATING PREGNANCY

5 % OF THE WORLD POPULATION

SUFFERS FROM THYROID DISEASE

CONGENITAL HYPOTHYRIODISM IS ONE OF

THE MOST COMMON CAUSES OF PREVENTABLE

MENTAL RETARDATION WORLD-WIDE

20 MILLION PEOPLE IN THE WORLD HAVE

VARIOUS DEGREES OF BRAIN DAMAGE

CAUSED BY IODINE DEFICIENCY IN UTERO

MEDICAL MANAGEMENT

OF THYROID DISEASE

By-

MOHAMMAD SADIQIII YR. M.B.B.S.

M.M.C.R.I.

THYROID DISORDERS

The conditions we will deal with here are:

1. Thyrotoxicosis

2. Hypothyroidism

3. Medical Emergencies > Myxoedema coma > Thyrotoxic crisis

4. Congenital Hypothyroidism (Cretinism)

5. Thyroid Disease complicating pregnancy

THYROID DISORDERSMEDICAL MANAGEMENT

1. Proper Clinical Diagnosis

2. Laboratory Evaluation

3. Treatment

4. Monitoring of patient

Proper management is based upon:

THYROTOXICOSISINTRODUCTION

“Defined as the state of thyroid hormone excess & is not synonymous with hyperthyroidism which is the result of excessive thyroid function”

Top 2 causes are:

Grave’s Disease (76%) Multi Nodular Goitre (14%)

HYPOTHYROIDISMETIOPATHOGENESIS

Iodine deficiency remains the leading cause World-wide.

In areas of iodine sufficiency the causes are:

1. Hashimoto’s thyroiditis2. Spontaneous Atrophic thyroiditis3. Iatrogenic causes

HYPOTHYROIDISM

PRESENTING COMPLAINT

HASHIMOTO’S THYROIDITIS:

• Symptoms of Goitre more than that of Hypothyroidism.

ATROPHIC THYROIDITIS:

• Symptoms of Hypothyroidism more than that of Goitre

HYPOTHYROIDISM

QUEEN ANNE’S SIGN MYXOEDEMA FACIES

THYROID DISEASE

CLINICAL PRESENTATION

Cardinal Features

HYPERTHYROIDISM:

• Presents with warm, moist skin

• sweating, Heat intolerance

• Von Muller’s Paradox

HYPOTHYROIDISM:

• Presents with tiredness, weakness

• Myxoedema

• Dry coarse skin, Cool peripheral extremities

• Cold intolerance

THYROID DISEASECLINICAL PRESENTATION

Dept. of General Medicine

HYPERTHYROIDISM:• Diabetes Mellitus• Palpitations• Diarrhoea• Eyes: Stellwag’s sign• Fatigue & wt. loss (Elderly patients)

HYPOTHYROIDISM:• Pleural Effusion• Pericardial Effusion• Constipation• Carpal Tunnel Syndrome• Bradycardia• Peripheral edema• Hoarse voice (phone diag)

THYROID DISEASE

GI PRESENTATION

Transit timeleads to

diarrhoea inthyrotoxicosis

THYROID DISEASEDept. of Dermatology

HYPERTHYROIDISM:

• Pretibial myxoedema

• Thyroid acropachy

HYPOTHYROIDISM:

• Diffuse alopaecia

Acropachy

PretibialMyxoedema

THYROID DISEASE

CLINICAL PRESENTATION

Dept. of Neurology

HYPERTHYROIDISM:

• Fine tremor

• Hyperreflexia

• Muscle wasting

• Proximal myopathy

• Hypokalemic periodic paralysis

HYPOTHYROIDISM:

• Paraesthesia

• Pseudomyoclonus

• Delayed tendon reflexes

• Difficulty in concentration

• Poor memory

THYROID DISEASEDept. of OBG

HYPERTHYROIDISM:

• Oligomenorrhoea

HYPOTHYROIDISM:

• Menorrhagia

THYROID DISEASE

Dept. of Psychiatry

HYPERTHYROIDISM:

• Anxiety neurosis

• Severe Depression

HYPOTHYROIDISM:

• Bipolar Disorder

• Depression

THYROTOXICOSIS

CVS MANIFESTATION

C/F:•Palpitations

•Sinus Tachycardia

•Bounding pulse

•Widened pulse pressure

•Aortic Systolic Murmur

•Worsening of Angina

•Atrial Fibrillation (>50yrs)

THYROTOXICOSIS

MANAGEMENT OF ATRIAL FIBRILLATION

• VR responds little to Digoxin.

• Good response to addition of - blockers.

• CARDIOVERSION to revert to sinus rhythm.

(Only after TSH/T4 )

• Anti coagulation with Warfarin / Aspirin.

• Generally control of serum T4 causes a return to sinus rhythm.

• Drugs provide symptomatic relief.

THYROTOXICOSIS

GRAVES’ OPTHALMOPATHY

• Gritty sensation, Discomfort, lacrymation

• Exopthalmous

• Periorbital oedema, Chemosis, Scleral injection

THYROTOXICOSIS

MANAGEMENT - GRAVES’ OPTHALMOPATHY

1. Reassurance

2. Methyl cellulose drops grittiness, discomfort

3. Tinted glasses / Side shields excess lacrymation

Complications:1. Corneal Ulcer: Lid lengthening Sx

2. Papilloedema/Loss of acuity/Field defects:

URGENT trt. with PREDNISOLONE 60mg/d

GRAVES’ OPTHALMOPATHY

EFFECT OF THERAPY

BEFORE AFTER

THYROTOXICOSIS

MANAGEMENT

3 approaches 1. Antithyroid drugs

2. Radioactive Iodine I131

3. Subtotal thyroidectomy

THYROTOXICOSISMEDICAL MANAGEMENT

1. ANTITHYROID DRUGS: > Carbimazole

> Propyl thiouracil

Dosage of Carbimazole:

0-3 weeks 40-60 mg daily

4-8 weeks 20-40 mg daily

Maintainence 5-20 mg daily for 18-24 months

ADR: Rash, Agranulocytosis

C/I: Lactating Mothers

THYROTOXICOSISMEDICAL MANAGEMENT

2. RADIOACTIVE I131 :

MOA: > Destroys functioning thyroid cells

> Inhibits their ability to replicate

Dose:

180-370 MBq (5-10mCi) orally (Dep. on goitre size)

• 4-6 weeks to be effective (long lag period)

-blockers control symptoms in lag period.

• Severe cases: Carbimazole within 48 hrs of I131

THYROTOXICOSISMEDICAL MANAGEMENT

3. Role of -blockers: ONLY SYMPTOMATIC RELIEF

(within 12-24 h)

Propronolol: 160 mg/day

Nadolol: 40-80 mg/day

T3 toxicosis : I131(555-110Mbq), Hemithyroidectomy

THYROTOXICOSISEFFECT OF TREATMENT

BEFORE AFTER

THYROTOXICOSISEFFECT OF TREATMENT

BEFORE AFTER

THYROTOXICOSISSPECIAL CASES

PENDRED’S SYNDROME:Dyshormonogenesis (T4) + Deafness

1.

HAMBURGER THYROTOXICOSIS2.

HYPOTHYROIDISMMEDICAL MANAGEMENT

Life long therapy with Levothyroxine (T4) is the sheet anchor

Start slowly with 50g/day OD – 3 weeks

Then to 100g/day OD – 3 weeks

Finally to 150g/day OD

Hypothyroidism following Grave’s Disease 75-125g/day OD

Improvement takes 2-3 weeks

HYPOTHYROIDISMMEDICAL MANAGEMENT

RATIONALE IN USING T4 IN HASHIMOTO’S:

1. Treatment of Hypothyroidism

2. Goitre shrinkage

T4 vs. T3 – Why T4?

T3 in high doses causes:• Angina• Arrythmias• Heart Failure

HYPOTHYROIDISMMONITORING THERAPY

1. Correct dose of drug: Restores serum TSH to lower part of reference range when T4 is / slightly .

2. Advise & reinforce need for regular medication.

3. TFT screening every 1-2 years.

T4 & TSH - ?

HYPOTHYROIDISMEFFECT OF TREATMENT

BEFORE AFTER

HYPOTHYROIDISMEFFECT OF TREATMENT

BEFORE AFTER

THYROID DISORDERSINVESTIGATIONS

Disorder TSH

(0.3-3.5 mU/L)

Free T4

(10-25 pmol/L)

Free T3

(3.5-7.5 pmol/L)

Thyrotoxicosis (<0.05mU/L)

Primary Hypothyroidism

(>10 mU/L) or

low normal

/

TSH deficiency Low normal / sub normal

or

low normal

/

T3 Toxicosis (<0.05 mU/L)

Compensated Euthyroidism

Slightly (5-10 mU/L)

MEDICAL EMERGENCIES

1. HYPERTHYROID CRISIS (= Thyrotoxic crisis / Thyroid storm)

2. MYXOEDEMA COMA

2 Situations :

HYPERTHYROID CRISIS

HYPERTHYROID CRISISMANAGEMENT

1. Rehydrated

2. Broad spectrum antibiotic

3. Propronolol 80 mg 6th hrly orally / 1-5 mg 6th hrly i.v.

4. Large doses of Propyl thiouracil 600 mg loading dose & 200-300 mg every 6 hrs orally/NGT/PR is the DOC.

5. Stable Iodine 1 hr later.

6. Saturated sol of KI / Na iopodate 500 mg/d orally restores normal levels of T3 within 48-72 hrs.

7. Others: Glucocorticoids, Cooling, Oxygen

MYXOEDEMA COMACLINICAL PICTURE

1. level of consciousness usually in an elderly patient who appears myxoematous

2. Body temperature as low as 25oC

3. Convulsions

4. CSF pressure & proteins

5. Mortality rate around 50%

(EARLY DETECTION is essential)

MYXOEDEMA COMAMANAGEMENT

TREATMENT must begin IMMEDIATELY

1. Triiodothyronine i.v. bolus 20g followed by 20g

8th hourly till there is sustained clinical improvement.

2. Liothyronine (T3) i.v. / NGT 10-25 g 8-12th hourly (v. rapid)

3. T3 (25g) + T4 (200g) as a single initial i.v. bolus followed

by daily trt. with Levothyroxine 50-100 g 8th hrly.

Others: Slow rewarming (if <30oC), Cautious use of i.v. fluids, Broad Spectrum antibiotics, High flow oxygen, Assisted ventilation

CRETINISM

“Children who are hypothyroid from birth / before are called cretins.”

WHO IS A CRETIN?

“What should have been an angel of God has been a pariah of nature just for the want of a little iodine in mother’s blood.”

CRETINISMGUESS MY AGE?

22 yr. old femalePot bellyUmbilical herniaCoarse facial featuresSupra clavicular pad of fat

CRETINISMGUESS MY AGE?

17 yr. old femaleCongenital hypothyroidismLarge earsEnlarged protruded tongueWide set eyesDepressed nasal bridgeShort limbsEstim. bone age : 9 months

CRETINISMRADIOLOGICAL PICTURE

CRETINISMMANAGEMENT

Monitoring of thyroid status of mother is important

If mother is…

Euthyroid• Dev. normal until birth• Manifests at birth• Treatment started at birth has good prognosis

Hypothyroid• Iodine def. is commonest cause• MR is more severe• Less responsive to trt.• Deaf mutism & rigidity +Intake of iodised salt has this

CRETINISMTREATMENT

Sodium Levothyroxine 100g tab is the DOC

Dose: Neonates: 10-15 g/kg/day

Older children: 4-8 g/kg/day

Neonates & Children < 1yr.: INITIATE trt. on DIAGNOSIS

DON’T WAIT for INVESTIGATIONS

CRETINISMMONITORING

1. Assess Clinical Milestones

2. Periodic TFT

3. Radiological estimation of bone age annually

Antenatal screening:

> Regular TFT – mother

> Foetus USG

THYROID DISEASE COMPLICATING PREGNANCY

HYPERTHYROIDISMHYPOTHYROIDISM

THYROID DISEASE COMPLICATING PREGNANCY

HYPERTHYROIDISM - MANAGEMENT

Carbimazole is the drug used

• Crosses placenta and also treats foetus• Imp to use the smallest dose possible• Review every 4 weeks

• Discontinue Carbimazole 4 weeks before EDD

If Hyperthyroid mother wants to feed?

Radioactive Iodine is C/I

THYROID DISEASE COMPLICATING PREGNANCY

HYPOTHYROIDISM - MANAGEMENT

Why treat?

On the basis of serum TSH measurements

most pregnant women with primary hypothyroidism

require an additional 50g thyroxine to their

usual dose ( TBG in pregnancy).

MEDICAL MANAGEMENTOF THYROID DISORDERS

CONCLUSION

1. Thyroid disease may have a variable clinical presentation.Hence, it is very essential to have a high degree of caution beforedeclaring a patient euthyroid. It is better to do a TFT in all suspected cases. The cost of the TFT is noting compared to the dire consequences of a missed diagnosis.

2. Treatment must be started immediately in all suspected casesof thyroid storm/myxoedema coma/cretinism as a delay in treatment might be fatal to the patient or may land the child in permanentmental retardation.