Hypothyroidism Protocol

Hypothyroidism may present with the following symptoms, signs or findings:-

• fatigue
• constipation
• weight gain
• memory and mental impairment
• dry skin and cold intolerance
• decreased concentration
• yellow skin
• depression
• coarseness or loss of hair
• irregular or heavy periods and infertility
• hoarseness
• myalgias (muscle pains)
• goitre
• raised blood fat levels
• reflex delay in the relaxation phase
• slow heart rate and hypothermia
• ataxia (unsteadiness and problems with co-ordination)
• myxedema - fluid infiltration of tissues

Patients presenting with symptoms suggesting hypothyroidism should be tested by blood test for thyroid stimulating hormone (TSH).

Patients on amiodarone or lithium treatment should be monitored regularly.

Diagnosis
Patients should be diagnosed as having hypothyroidism if they have clinical features and a Raised TSH with or without thyroid microsomal antibodies.

Subclinical Hypothyroidism (raised TSH without symptoms) should be treated if TSH >10 or if thyroid autoantibodies present, otherwise monitor by repeating blood test within 6 months.

Assessment
At the first visit:-

• measure weight
• assess cardiac state - pulse.
• assess any symptoms of ischaemic heart disease (IHD)

Management

Under 65	Over 65 or IHD
Thyroxine 50 mcg daily starting dose	Thyroxine 25mcg daily starting dose
4 weekly check TSH, Wt, Cardiac Status	4 weekly check TSH,Wt, Cardiac Status
Increase Thyroxine by 50mcg daily	Increase Thyroxine by 25mcg daily

Aims
TSH in therapeutic range 0.3-4.5. Levels above this represent inadequate replacement levels. Levels below present danger of Atrial Fibrillation.
Thyroxine doses of 200mcg daily with elevated TSH probably represent poor compliance
Annual check of TSH should ensure good control

May 2000