Hypothyroidism, or an underactive thyroid, is a common endocrine disorder in Australia that requires ongoing management to restore and maintain normal thyroid hormone levels. The primary goal of treatment is to relieve symptoms and normalize metabolic function by replacing the deficient thyroid hormones. Here’s an in-depth look at how hypothyroidism is treated in Australia, focusing on current medical practices and patient care.
The Mainstay of Treatment: Levothyroxine Therapy
In Australia, the standard and most effective treatment for hypothyroidism is thyroid hormone replacement therapy using levothyroxine (also called thyroxine). Levothyroxine is a synthetic form of the natural thyroid hormone T4 and is taken orally, usually once daily.
- Dosage and Administration: Treatment typically begins with a dose tailored to the patient’s weight, age, and clinical condition. The average starting dose is approximately 1.6 micrograms per kilogram of body weight per day for healthy adults. However, lower initial doses are recommended for elderly patients, those who are frail, or individuals with heart disease to avoid overstressing the heart.
- Timing: Levothyroxine should be taken on an empty stomach, ideally 15 to 30 minutes before breakfast, to maximize absorption. Consistency in timing is important for maintaining stable hormone levels.
- Monitoring: After starting therapy, thyroid function tests, particularly TSH levels, are checked after 6 to 8 weeks to adjust the dose as needed. The goal is to bring TSH into the normal range (typically between 1.0 and 3.0 mIU/L). Once stabilized, patients usually require annual blood tests to monitor thyroid function and adjust treatment if necessary.
Managing Subclinical Hypothyroidism
For patients with mild or subclinical hypothyroidism (elevated TSH but normal thyroid hormone levels), treatment decisions are more nuanced:
- If TSH levels are above 10 mIU/L or if symptoms are present, a trial of levothyroxine for several months may be recommended to assess symptom improvement.
- For TSH levels between 5 and 10 mIU/L, treatment may be considered if thyroid antibodies are positive or if a goitre is present. Otherwise, regular monitoring with periodic blood tests may be sufficient.
- Women planning pregnancy with subclinical hypothyroidism are generally advised to start treatment due to the importance of thyroid hormones in fetal development.
What About Combination Therapy or Alternative Treatments?
Some patients continue to experience symptoms despite normal TSH levels on levothyroxine alone. In these cases, combined therapy with liothyronine (T3) and levothyroxine has been explored, but current evidence does not conclusively show superiority over levothyroxine monotherapy. Therefore, combination therapy is not routinely recommended.
Desiccated thyroid extracts, derived from animal thyroid glands, are not approved for use in Australia due to concerns about inconsistent hormone content and potential safety risks.
Special Considerations
- Heart Disease and Elderly Patients: Starting doses should be lower to reduce the risk of cardiac side effects.
- Pregnancy: Thyroid hormone requirements often increase during pregnancy, necessitating close monitoring and dose adjustments.
- Drug Interactions: Certain medications and supplements can interfere with levothyroxine absorption, so patients should inform their doctors about all substances they are taking.
Long-Term Outlook
Hypothyroidism treatment is generally lifelong, as the underlying causes (such as autoimmune thyroiditis) are chronic. With appropriate hormone replacement and regular monitoring, most patients can expect a normal quality of life and symptom resolution.
In summary, hypothyroidism treatment in Australia centers on carefully dosed levothyroxine therapy, individualized to each patient’s needs and monitored through regular blood tests. This approach effectively restores thyroid hormone balance, alleviates symptoms, and prevents complications. If you suspect hypothyroidism or have been diagnosed, working closely with your healthcare provider is essential to optimize your treatment plan.