Treatment for Graves Disease

The thyroid gland is the main regulator of metabolism in a person's body. In healthy people, the thyroid gland produces two hormones: trioiodothyronine (T3) and thyroxine (T4) in perfect balance to maintain normal body functions. The body can be thrown into a state of hyperthyroidism when too much of the thyroid hormones are produced. Grave's disease is the most common form of hyperthyroidism affecting women 5-10 times more often than men (Allahabadia, et al., 2000). Torring et al. (1996) defines Grave's disease as the "presence of symptoms and signs of hyperthyroidism, nonodular thyroid gland, and elevated total and free serum T4 and/or total T3 levels" (p 2987). Some effects of this autoimmune disease can be dramatic including extreme weight loss, opthalmopathy, hand tremors, severe muscle weakness, and irritability. Treatment is aimed at stabilizing the overactive thyroid either by surgery, antithyroid drugs, or radioiodine therapy. Treatment options vary in their risks and benefits for patients, and because of this fact it can often be very confusing for clients as to which therapy is right for them. Because the effects of Grave's disease and its' treatments can profoundly affect a person's life, it is imperative nurses understand the emotional implications of making therapy decisions and stand ready to educate and support their patients in their treatment of choice. The purpose of this integrated literature review is to discuss the risks and benefits of antithyroid drug treatment, and radioiodine therapy for Grave's Disease and how knowledge of these treatments is essential to nurses.

Methods

Five primary research studies were found using the MEDLINE database. Search terms used were hyperthyroidism and treatments. The search was limited to peer reviewed articles published in English, with the full text link, and generally newer than 1997. One article from 1996 was included with professor permission because of its pertinence to the review. Articles specifically about Grave's disease, antithyroid drugs, or radioiodine were included, while articles about other forms of hyperthyroidism, thyroidectomy, or literature reviews were excluded.

Results

Benefits of Drug Therapy

Drug therapy for Grave's disease may yield many benefits. For example, treatment with antithyroid drugs reduces a patient's risk of developing thyroid cancer because there is no radiation involved with therapy (Angusti, Codegone, Pellerito, & Favero, 2000). Also, according to Torring's et al. (1996) study about the risks and benefits of each treatment modality for Grave's disease, antithyroid drugs quickly normalized patient hyperthyroid levels within six weeks. Bartelena's et al. (1998) study of 443 patients with Grave's disease found patients on antithyroid drugs to have a decreased chance of developing or worsening opthalmopathy. Furthermore, 2% of patients in this study taking antithyroid drugs actually displayed improvement with their eye disease after therapy. Another benefit of antithyroid drugs is they kill the thyroid gland slowly, making it less likely for a patient to develop hypothyroidism after treatment ( Bartelena et al.). In Torring's et al. (1996) study, none of the 60 patients treated with antithyroid drugs became hypothyroid after therapy. After a few years of treatment, some patients may be able to get off of their antithyroid drugs completely, because the thyroid is adequately stable.

Benefits of Radioiodine Therapy

Similarly to antithyroid drugs, radioiodine therapy is also very effective at bringing hyperthyroid levels down quickly. A benefit specific to radioiodine however, is the impossibility of hyperthyroidism relapsing. Radioiodine therapy kills the thyroid completely usually in one or two doses of the pill (Törring et al., 1996). Hospitalization is not required for radioiodine, and the therapy is usually well tolerated (Angusti et al., 2000). Torring et al. (1996) found that more patients who were randomized to be treated with radioiodine would recommend this form of treatment to their friends than the patients who were taking antithyroid drugs.

Risks of Drug Therapy

Although antithyroid drug therapy may enable a patient to get off of their medication after a while, the risk of Grave's disease relapse with this treatment modality is high. Torring's et al. (1996) study found that out of the 68 patients randomized to receive antithyroid drugs that completed their therapy, 42% of young adults (10 out of 24) and 34% of old adults (12 out of 35) experienced a relapse of Grave's disease. Only 59 patients completed their treatment due to the fact that 11 patients experienced adverse effects to the medication (Torring et al.). It does not matter what antithyroid drugs a patient takes, the risk of relapse is still high when compared to radioiodine therapy (Raber, Kmen, Waldhäusl, & Vierhapper, 2000).

Risks of Radioiodine Therapy

Although considered the first-line treatment for Grave's disease in the United States, radioiodine therapy poses risks as well. For example, treatment with this modality produces hypothyroidism in most patients because the thyroid gland is ablated (Allahabadia et al., 2000). While patients do not have to deal with relapse of their disease, they have to face the symptoms of hypothyroidism. Torring et al. (1996) found that all 39 patients who received radioiodine therapy developed hypothyroidism. Sometimes patients need more than one dose of the treatment, furthering their chance of becoming hypothyroid. More males than females required another dose of radioiodine according to Allahabadia et al. (2000). This finding can be contributed to the dose of radioiodine received, and the levels of serum free T4 in the males blood at the beginning of treatment. Allahabadia et al. suggests that "higher initial doses of radioiodine in males be evaluated" (p 1038).

Another risk of treatment with radioiodine encompasses developing or worsening of opthalmopathy. In Bartalena's et al. (1998) study of the relationship between this eye disease and hyperthyroidism, 150 patients were randomly assigned to be treated with radioiodine, while another 145 patients received radioiodine and prednisone. Bartalena et al. found that "among the 150 patients treated with radioiodine alone, opthalmopathy developed or worsened in 23 patients (15%) during the year after treatment" (p 75). Opthalmopathy in 15 of these patients was transient and went away within two to three months. Those patients treated with radioiodine and prednisone either had a decrease in their opthalmopathy or no change at all. From these results, Baratalena et al. concluded that "worsening of opthalmopathy after radioiodine therapy is often transient and can be prevented by the administration of prednisone" (p 73).

In past years radioiodine therapy was thought to lead to a higher incidence in thyroid tumors because radiation to the neck is a risk factor for thyroid cancer (Angusti et al., 2000). In this retrospective study of thyroid cancer prevalence after treatment with radioiodine, data was collected on 6647 patients, 1586 of which had hyperthyroidism in the form of Grave's disease. After treatment with radioiodine, thyroid cancer was found in 10 patients, none of whom had Grave's disease. From these results researchers concluded that in terms of Grave's disease, it appears that thyroid cancer with radioiodine treatment is not a major threat (Angusti et al.).

Further Research/Limitations

Further research still needs to be performed to strengthen the literature's findings. Limitations include factors such as smoking affecting the course of opthalmopathy, and how long patients have hyperthyroidism before treatment (Bartalena et al., 1998). Angusti et al. (2000) mentions the limitation of their study on thyroid cancer being done in Italy where goiters are more prevalent than Grave's disease.

Conclusion

Based on a review of the literature, the main risks and benefits of anti-thyroid drug treatment and radioiodine therapy for Grave's disease are clearer. With anti-thyroid drugs, a patient will not become hypothyroid, but the chance of Grave's disease relapse is high. Radioiodine offers a sure cure of hyperthyroidism, but then patients are faced with the challenge of regulating thyroid hormones being too low.

Nurses play a key role in being educators and advocates for patients and their families. When caring for someone who has Grave's disease, or any other illness, it is essential that nurses are able to answer patient questions about their treatment. Nurses need to be up to date on research so they can collaborate with physicians and offer support to patients in their treatment decisions using evidence from the literature.

References

Allahabadia, A., Daykin, J., Holder, R. L., Sheppard, M. C., Gough, S. C., & Franklyn, J. A. (2000). Age and gender predict the outcome of treatment for graves' hyperthyroidism.

The Journal of Clinical Endocrinology and Metabolism, 85(3), 1038-1042.

Angusti, T., Codegone, A., Pellerito, R., & Favero, A. (2000). Thyroid cancer prevalence after radioiodine treatment of hyperthyroidism.

Journal of Nuclear Medicine, 41(6), 1006-1009.

Bartalena, L., Marcocci, C., Bogazzi, F., Manetti, L., Tanda, M. L., Dell'Unto, E., et al. (1998). Relation between therapy for hyperthyroidism and the course of graves' ophthalmopathy.

The New England Journal of Medicine, 338(2), 73-78.

Raber, W., Kmen, E., Waldhäusl, W., & Vierhapper, H. (2000). Medical therapy of graves' disease: Effect on remission rates of methimazole alone and in combination with triiodothyronine.

European Journal of Endocrinology, 142(2), 117-124.

Törring, O., Tallstedt, L., Wallin, G., Lundell, G., Ljunggren, J. G., Taube, A., et al. (1996). Graves' hyperthyroidism: Treatment with antithyroid drugs, surgery, or radioiodine--a prospective, randomized study. thyroid study group.

The Journal of Clinical Endocrinology and Metabolism, 81(8), 2986-2993.