thy·roid (th  roid )n. 1. The thyroid gland. 2. The thyroid cartilage. 3. A powdered preparation of the thyroid gland of certain domestic animals, used in the treatment of cretinism and myxedema, in certain cases of obesity, and in skin disorders. thy roid adj.thy·roi dal adj. |
Thyroid
thyroid.
thyroid [thi´roid]
Thyroid crisis is a serious event that can be fatal if not brought under control. All of the body processes are accelerated to dangerously high levels. The pulse may rise to 200 beats per minute, and there is concurrent rise in the respiratory rate. The temperature control center loses control, bringing about a rapid and steady increase in body temperature. Pulmonary edema and congestive heart failure can also occur.
Treatment is aimed at correction of the hyperthyroidism, control of the symptoms, and prevention of further crisis by treating the underlying cause. Medications are employed to block synthesis of thyroid hormones, block their release, and inhibit conversion of triiodothyronine to thyroxine. plasmapheresis. plasma exchange, or hemodialysis may be necessary to remove the hormones from the circulation.
Supportive care includes administration of oxygen and measures to control hyperthermia, such as the use of ice packs or a hyperthermia blanket. Intravenous hydration is important to prevent shock. The use of glucocorticoids is associated with improved survival rates. propranolol, sympatholytics, and guanethidine are often used, as well as other medications that treat symptoms.
Diagnostic tests for thyroid disorders include radioimmunoassay for T3, T4, and thyroid-stimulating hormone (TSH), free thyroxine serum concentration, and free thyroxine index (FTI). These and other thyroid function tests can be distorted by preparations and foods containing iodine, and by oral contraceptives, phenytoin (Dilantin), and several other drugs. The thyroid scan is useful in detecting nodules and active thyroid tissue and, combined with radioactive iodine uptake, measures the ability of the thyroid gland to take in ingested iodine.
Persons who received radiation to the head and neck as children are at higher than normal risk for development of thyroid abnormalities. Of these disorders about one-third are carcinomas of the thyroid. Other problems related to radiation early in life include adenomas and other malignant and benign tumors, hypo- and hyperthyroidism, and thyroiditis. The American Thyroid Association suggests periodic laboratory testing and physical assessment of persons at high risk in order to detect these abnormalities when they are more amenable to treatment.
Secretion of thyroid hormones is regulated by the hypothalamus-pituitary-thyroid control system. Internal environmental conditions, such as low thyroid hormone and norepinephrine serum levels, or external factors, such as cold and stress, activate the hypothalamus, which secretes thyrotropin-releasing hormone (TRH). This hormone acts on the pituitary gland and brings about the release of thyroid-stimulating hormone (TSH). The TSH then stimulates the release of thyroid hormones such as T3 and T4 from the thyroid gland. When sufficient levels of serum thyroxine and other thyroid hormones have been reached, there is negative feedback to the hypothalamus and TRH is no longer secreted. See also hypothyroidism and hyperthyroidism.
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thyroid, desiccated
Armour Thyroid, Thyrar, Thyroid Strong, Westhroid
Pharmacologic class: Hormone supplement
Therapeutic class: Thyroid hormone
Pregnancy risk category A
FDA Boxed Warning
• Drug shouldn't be used alone or with other agents to treat obesity or weight loss. In euthyroid patients, doses within range of daily hormonal requirements are ineffective for weight loss. Larger doses may cause serious or life-threatening toxicity, particularly when given with sympathomimetic amines (such as those used for anorectic effects).
Action
Regulates cell growth and differentiation and increases metabolic rate of body tissues; effects mediated at cellular level
Availability
Tablets: 15 mg, 30 mg, 60 mg, 90 mg, 120 mg, 180 mg, 240 mg, 300 mg
⊘Indications and dosages
➣ Mild hypothyroidism
Adults: Initially, 60 mg/day P.O.; may increase by 60 mg q 30 days to desired response. Usual maintenance dosage is 60 to 180 mg/day.
➣ Severe hypothyroidism
Adults: Initially, 15 mg/day P.O. daily; may increase to 30 mg/day after 2 weeks and then to 60 mg/day 2 weeks later. Assess after 1 month, and again 1 month later at 60 mg-dose. If necessary, dosage may then increase to 120 mg/day P.O. for 2 months, with assessment repeated. Subsequent assessments and dosage increases may occur up to a maximum of 180 mg/day.
➣ Congenital or severe hypothyroidism
Children: Initially, 15 mg P.O. daily; may increase to 30 mg/day after 2 weeks, with subsequent increases at 2-week intervals. Maintenance dosage may be higher in growing children than in hypothyroid adults.
Dosage adjustment
• Cardiovascular disease
• Elderly patients
Contraindications
• Hypersensitivity to drug or its components
• Adrenal insufficiency
• Thyrotoxicosis
Precautions
Use cautiously in:
• tartrazine sensitivity (some products)
• cardiovascular disease
• elderly patients
• breastfeeding patients.
Administration
• Give before breakfast each day.
| Route | Onset | Peak | Duration |
| P.O. | Unknown | 12-48 hr | Unknown |
Adverse reactions
CNS: insomnia, tremors, headache
CV: palpitations, angina pectoris, hypertension, tachycardia, arrhythmias, cardiac arrest
GI: nausea, vomiting, diarrhea
GU: menstrual irregularities
Metabolic: heat intolerance, thyroid storm
Musculoskeletal: accelerated bone maturation (in children)
Skin: sweating
Other: weight loss, appetite changes, fever
Interactions
Drug-drug. Anticoagulants, catecholamines, sympathomimetics: increased effects of these drugs
Bile acid sequestrants: decreased thyroid hormone absorption
Digoxin, insulin, oral hypoglycemics: decreased effects of these drugs
Estrogen: decreased thyroid hormone effects
Oral anticoagulants: increased risk of bleeding
Drug-diagnostic tests. Aspartate aminotransferase, creatine kinase, glucose, lactate dehydrogenase, protein-bound iodine: increased levels
Thyroid function tests: decreased values
Drug-herbs. Bugleweed, soy: increased adverse drug reactions
Patient monitoring
☞ Monitor for chest pain. If it occurs, withhold drug and contact prescriber.
• Assess vital signs and temperature frequently.
☞ Monitor thyroid function tests closely. Immediately report evidence of thyroid storm.
• In diabetic patient, monitor blood glucose level closely.
• In children, monitor sleeping pulse rate and morning basal temperature.
• In female on long-term therapy, monitor bone density tests.
Patient teaching
• Tell patient to take each morning before breakfast.
☞ Caution patient not to stop therapy abruptly. Dosage must be tapered.
☞ Advise patient to immediately report chest pain or signs and symptoms of drug toxicity (fever, chest pain, rapid pulse, skipped heartbeats, heat intolerance, excessive sweating, nervousness, emotional instability).
• Instruct patient to tell all prescribers he's taking drug. Caution him not to use over-the-counter preparations without consulting prescriber.
• Tell diabetic patient that drug may alter blood glucose level. Encourage frequent glucose self-monitoring.
• As appropriate, review all other significant and life-threatening adverse reactions and interactions, especially those related to the drugs, tests, and herbs mentioned above.
thyroid
Patient discussion about thyroid.
Q. Has anyone tried natural hormones for hypo-thyroidism or fibromyalgia? I am on the low normal range for hypo-thyroidism (do not take meds for) and was diagnosed years ago with fibromyalgia. I take Ultram for the pain which also helps my fatigue factor but I still feel so sluggish sometimes and just want to sleep. I'm on an anti-depressant as it is. I've been hearing more about natural hormone therapy for these conditions and was wondering if anyone out there has tried this.
Q. What Are the Symptoms of Hypothyroidism? My friend suffers from hypothyroidism. I have been feeling tired lately and she told me I should get examined too. What are the symptoms of this disease?
Q. Anyone know if there is a connection between Fibromyalgia and your Thyroid gland? I have Fibromyalgia and I read that if your diagnosed with this you can have Thyroid problems also. If anyone knows out there please inform me. Many thanks.
http://thyroid.about.com/cs/fibromyalgiacfs/a/fibrothyroid.htm
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