Hypothyroidism, diagnosis and treatment

1. Protocol for Management of Hypothyroidism:
A consensus of GCC Countries
A Thyroid Roadmap
Guidance for healthcare professionals addressing the management of hypothyroidism in
GCC Countries.
Written by the Saudi Arabia and Gulf Thyroid Advisory Board
Presented by
Professor mohammed Ahmed Bamashmos (MD)

2. Objectives
• to educate the health care physicians on the protocol
for management of hypothyroidism
• After attending this lecture the HCP will be able to know
how to do patient screening
• Will understand how to manage hypothyroidism in
pregnancy, new born and obese patients
• will know the algorithm of hypothyroidism
management.
• Will know the exact dosing of levothyroxine to be used
with each patients

3. Disclosures
PB is in receipt of an honorarium from
Merck during this Meeting lecture.
However, Merck have had no influence
on the content and views expressed
during this lecture

4. Introduction
▶ Hypothyroidism is caused by inadequate production of thyroid hormones or inadequate replacement
following thyroidectomy which leads to low circulating and tissue levels of thyroid hormones1
▶ As hypothyroidism is common and frequently underdiagnosed, millions of people worldwide are unaware
that they have the disease and remain untreated1
▶ In the GCC (Gulf Cooperation Council) countries, the prevalence of hypothyroidism ranges from 7% to 41%,
and rates of subclinical hypothyroidism are typically more than twice that reported in the USA2,3
▶ A high prevalence rate of hypothyroidism is typical among pregnant women in the GCC countries4
▶ Untreated hypothyroidism can contribute to hypertension, dyslipidemia, infertility, cognitive impairment,
and neuromuscular dysfunction1
▶ There are currently inconsistency and some controversies in the management of hypothyroidism in the
GCC countries
▶ This roadmap has been developed by leading GCC endocrinologists and policy advisors to provide
recommendations on the diagnosis and management of hypothyroidism in the GCC countries
Rationale for the diagnosis and management of hypothyroidism roadmap

6. Patient Screening
It is recommended that the following patients be screened for hypothyroidism by measurement
of plasma Thyroid stimulating hormone (TSH) level.
Figure 1: Screening recommendations5
Figure 1: Screening recommendations5
Screen the following patient groups
for possible hypothyroidism
Patients with 4 or more of
the following symptoms:
Patients with a history of:
Plasma TSH measurement
Pregnant patients
with a history of:

8. Diagnosis of hypothyroidism
Patients who are found to have an elevated TSH level are classified into two groups according to
their free thyroxine (FT4) level; subclinical and overt hypothyroidism.
Figure 2: Determining pathways for hypothyroidism patients1,6,7
Patient tested for TSH
and FT4 levels
TSH is elevated
(>10 mu/l)
and FT4 is low
Patient has elevated
TSH, but normal FT4
Diagnosed as having overt
hypothyroidism
and should be treated
Diagnosed as having subclinical
hypothyroidism and the management
algorithm on the next page is
recommended to be followed

9. When administration of levothyroxine is
necessary
• Hypothyroidism is a common endocrine disease that requires
timely and lifelong treatment since, if left untreated, it can
contribute to hypertension, dyslipidaemia, and heart failure and
induce reversible dementia and infertility, as well as
neurosensory, musculoskeletal, and gastrointestinal symptoms
[7]. There is currently no other treatment for hypothyroidism,
other than providing thyroid hormone replacement.

10. • Due to its long half-life of about 7 days, in patients in the
clinically euthyroid state, levothyroxine is the preferred first-
line treatment for primary hypothyroidism and has been the
most commonly prescribed treatment since the 1980s [8].

11. Management of Hypothyroidism
This algorithm shows how patients with overt and sub-clinical hypothyroidism should be
managed.
Figure 3: Management algorithm for patient with hypothyroidism
Elevated TSH
Overt hypothyroidism Subclinical hypothyroidism
TSH > 10 mU/I for second time TSH level 5-10 mU/I for second time
Thyroid peroxidase (TPO) - antibody positive Thyroid peroxidase (TPO) - antibody negative
Compelling indication* No compelling indication*
Repeat
TSH in1–3
months
Observe
Treat
*Compelling indication: Infertility,
recurrent abortions, pregnancy,
goiter, childhood, significant
persistent hypothyroid symptoms

12. Levothyroxine treatment dosing schedule
The following table provides the levothryoxine dosing schedule:
Levothyroxine should be taken:
• On an empty stomach
• At least 1 hour before the meal, usually the breakfast
These drugs should be administered at least 4 hours either side
of levothyroxine dose to minimize possible interactions:
• Calcium supplements
• Proton-pump inhibitors
• Bile acid sequestrants (cholestyramine and colesevelam)
• Biophosphonates
• Ferrous sulfate
• Aluminium-containing antacids
• Sucralfate
• Anticonvulsants
Figure 4: How should levothyroxine be taken?1,6

13. Factors that should be considered
• 1
- age
• 2
- sex
• 3
- body weight
• 4
- pregnancy
• 5
- medical conditions
• 6
- medication

14. Risk factors that should be considered

15. Starting dose

17. Management of adults
Figure 5: Management of adult patients6
Newly diagnosed, healthy, young to middle
aged patients (<65 years of age) who have
no comorbidities or cardiovascular risk
factors
Full levothyroxine starting dose:
1.6 μg/kg body weight

18. Management of elderly patients
Figure 6. Management of elderly patients 6,8
In the elderly, the TSH level may normally be slightly over the
normal range and therefore should not be automatically treated.
It is recommended to look for the following before initiating
treatment
Symptoms or signs suggestive of
hypothyroidism, associated
cardiovascular disease or multiple
risk factors for cardiovascular
disease, and/or positive anti TPO
antibodies
No signs or
symptoms
Levothyroxine therapy could be
considered at starting dose of 25–
50mcg/day, raised by 25mcg every
1–2 weeks until the full dose is
reached
A period of
observation and
reassessment is
recommended

19. Management of pregnant women
Figure 7. Management of pregnant women8
Levothyroxine-titrated dose to keep TSH within
trimester-specific range
• First trimester: 0.1–2.5 mU/l
• Second trimester: 0.2–3.0 mU/l
• Third trimester: 0.3–3.0 mU/l
Serum thyrotropin levels assessed every 4 weeks during
first half of pregnancy to allow dose adjustment
Serum thyrotropin reassessed during second half of
pregnancy every 4-6 weeks to allow dose adjustment

22. Body weight
• Body weight, BMI, ideal body weight, and lean body mass can
all predict the initial dose requirement, with the latter three
parameters providing the more accurate estimates [10, 13].
Various formulae have been proposed to calculate dose
requirement. These range from simple formulae based only on
body weight or BMI to more complex formulae that also
incorporate other factors such as patient sex [10, 14].

24. According to etiology
• 1
– autoimmune
• Full dose
• 2
– post surgical
• - subtotal

25. • In the case of surgically athyreotic patients, the dose of
levothyroxine required may be slightly higher than in those
with autoimmune thyroid disease [8], presumably reflecting
some retained thyroid hormone production in those with
autoimmune thyroid disease. An example of the dose
requirement in those with Hashimoto’s thyroiditis without
residual function and post-surgical hypothyroidism is
approximately 1.6 μg/kg

26. indication of levothyroxine therapy SCH

28. Treatment target
• Levothyroxine starting dose
• • Neonates to 6 months: 10-15 mcg/kg/day
• • 6 months to 1 year: 8-10 mcg/kg/day
• • 1-2 years: 6-8 mcg/kg/day
• • Older than 2 years: 5-6 mcg/kg/day

30. • when TSH levels were maintained in the recommended
reference ranges in the guidelines (0.4 – 4 mIU/L).
Conversely, the risk of heart disease, stroke, broken bones
and death was higher in hypothyroid patients with TSH levels
outside the recommended reference range. Importantly, this
range offers flexibility in treatment since patients may feel
better at different TSH levels

31. Treatment adjustment
factors that could be considered
1- age and sex
2- body weight
3- patients adherence
4- timing of dose
5- pregnancy
6- use of certaion medication
7- associated medical diseases
8- ovoid over or under replacements

32. • Regardless of the method used to estimate the initial
levothyroxine dose requirement, dose adjustment is
frequently required. This may be due to multiple factors
including limitations in the dose requirement predictions,
inter-patient variation, levothyroxine absorption, or effects
of concomitant medical conditions or medicationsGiven the
half-life of levothyroxine (approximately 1 week),
reassessment of thyroid status by serum TSH levels, and
free thyroxine levels if desired, is indicated after 6 weeks of
therapy when the pharmacokinetic steady state is reached.
If the TSH is not at the desired goal, the levothyroxine dose
can be adjusted up or down. TSH values that are slightly out
of range may be corrected by a single dose increment or
decrement, such as increasing from 100 to 112 μg or
decreasing from 175 to 150 μg.

33. • TSH values that are considerably out of range may
require larger percentage changes. Levothyroxine
absorption is maximised, at about 75% of the
administered dose, when it is ingested upon an empty
stomach [8]. Therefore, if levothyroxine is taken at
other times of the day for convenience, the dose
requirement may be greater and potentially more
variable [15]. Once the desired TSH value has been
achieved, it could potentially be re-confirmed by
laboratory testing in 3–6 months, and then checked on
an annual basis thereafter.

35. Treatment adjustment

37. Refractory hypothyroidism

41. Key summary points
Hypothyroidism is common, but often underdiagnosed disease.
All patients at-risk or possible risk of hypothyroidism should undergo measurement of plasma
TSH level.
The decision to initiate treatment depends on multiple factors including baseline TSH and FT4
levels, symptoms and signs, TPO-positivity, comorbidities, patient age, fertility, thyroid size and
other factors.
Pregnant women, elderly patients, and children have different clinical considerations and/or
TSH cut-off levels which require different thyroid replacement approaches and doses.
These expert recommendations should help to guide clinicians in the diagnosis and
management of patients with hypothyroidism in GCC countries.

42. References
1. Gaitonde DY, Rowley KD, Sweeney LB. Hypothyroidism: An Update. Am Fam Physician. 2012; 86: 244–251.
2. Al Shahrani AS, El-Metwally A, Al-Surimi K, et al. The epidemiology of thyroid diseases in the Arab world: A systematic
review. J Public Health Epidemiol. 2016; 8: 17–26.
3. Taha I, Alhazmi J. Prevalence of overt and subclinical hypothyroidism among Saudi pregnant women attending tow
referral hospitals in Saudi Arabia and associated maternal and fetal complications. Endocrine Abstracts 2011; 25: P312.
4. Canaris GJ, Manowitz NR, Mayor G, Ridgway EC. The Colorado thyroid disease prevalence study. Arch Intern Med. 2000;
160: 526–534.
1. Garber JR, Cobin RH, Gharib H, et al. Clinical practice guidelines for hypothyroidism in adults: cosponsored by the
American Association of Clinical Endocrinologists and the American Thyroid Association. Endocr Pract. 2012; 18: 988-
1027.
2. Jonklaas J, Bianco AC, Bauer AJ, et al,. Guidelines for the treatment of hypothyroidism.Thyroid 2014; 24: 1670–1751.
3. Surks MI, Ortiz E, Daniels GH, et al. Subclinical thyroid disease: scientific review and guidelines for diagnosis and
management. JAMA. 2004; 291: 228-238.
4. Stagnaro-Green A, Abalovich M, Alexander E, et al.Guidelines of the American Thyroid Association forthe diagnosis and
management of thyroid disease during pregnancy and postpartum. Thyroid 2011; 21:1081–1125.
Contact details
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This roadmap is made possible thanks to an educational grant received from Merck Serono Middle East FZ-LLC