Synthroid is the brand name for the generic drug levothyroxine. It is the most commonly prescribed medication for hypothyroidism, in which the patient suffers from an underactive thyroid gland. The British Medical Journal reports that over 9 percent of women get diagnosed with hypothyroidism at some point in their lives. Synthroid is generally a safe drug that is well tolerated. Most side effects occur either at the initiation of treatment, or if the dosage is too high. Side effects should be directly reported to the prescribing physician, so that dose adjustments can be made.
General
General side effects include increased appetite, fatigue and weight loss. Other general effects consist of increased body temperature and profuse sweating, which causes the patient to become heat intolerant.
Heart Related
Cardiac side effects include: rapid heart rate, palpitations, arrhythmias and elevated blood pressure. Other rarer but potentially lethal consequences include angina, heart failure and heart attack. A patient experiencing any such symptoms should seek medical attention immediately.
Nervous System
Synthroid can cause headaches, nervousness or agitation, irritability and generalized anxiety. Insomnia or frequent awakening has also been reported. In rare but severe cases, a patient may develop confusion or psychosis.
Digestive System
Gastrointestinal side effects are common during the first week of starting synthroid therapy. These include vomiting, diarrhea, and intestinal cramps or spasms. In most cases, these subside after the first week or two of treatment.
Respiratory System
Synthroid can cause difficult or labored breathing. It can also lead to wheezing. Caution is needed if the patient has a history of asthma.
Muscle and Skin Systems
Other synthroid effects include muscle weakness and twitching. Synthroid can also induce hair loss and flushing of the skin.
Reproductive System
Synthroid has been known to cause menstrual irregularities and infertility issues, although these complications are rare.
References
- ABQ Medical Journal: Synthroid Side Effects
- eMedTV.com: Synthroid Side Effects
- "Diagnosis & Treatment of Hypothyroidism"; British Medical Journal; A. Allahabadia; March 2009
