What are the longtime side effects of taking synthroid?

Side effects from using Synthroid for a long time are not common. But effects on bone mineral density in women using long-term levothyroxine sodium therapy (Synthroid) has been associated with increased bone resorption, thereby decreasing bone mineral density, especially in post-menopausal women on greater than replacement doses or in women who are receiving suppressive doses of synthroid. The increased bone resorption may be associated with increased serum levels and urinary excretion of calcium and phosphorous, elevations in bone alkaline phosphatase and suppressed serum parathyroid hormone levels. THerefore, it is better to recieve the minimum dose necessary to obtain the desired clinical and biochemical response.

Overdose can occur when taking inappropriate doses of synthroid. People who are treated with this drug may initially lose some hair, but this effect is usually temporary. You may have an allergic reaction such as a rash or hives. Children may have an increase in pressure within the skull. Excessive dosage or a too rapid increase in dosage may lead to overstimulation of the thyroid gland. Notify your doctor immediately if you develop any of the following symptoms.

Here is a list of possible symptoms of overstimulation:
Abdominal cramps, anxiety, changes in appetite, change in menstrual periods, chest pain, diarrhea, emotional instability, fatigue, fever, flushing, hair loss, headache, heart attack or failure, heat intolerance, hyperactivity, increased heart rate, irregular heartbeat, irritability, muscle weakness, nausea, nervousness, palpitations, shortness of breath, sleeplessness, sweating, tremors, vomiting, weight loss

An overdose of Synthroid can produce the same symptoms of overstimulation. Confusion and disorientation are also possible, and there have been reports of stroke, shock, coma, and death. If you suspect a massive overdose, seek emergency medical attention immediately.

The best way to ensure you are taking the appropirate dose is to have your physician monitor the symptoms and doses in a regular basis. The adequacy of therapy is determined by periodic assessment of appropriate laboratory tests and clinical evaluation by your healthcare provider.

You can find additional information on this drug at: http://www.rxlist.com/synthroid-drug.htm