Side Effects of Synthroid levothyroxine: Interactions & Warnings

Levothyroxine is a medication that is generally taken for life to maintain normal thyroid function. Because of the increased prevalence of cardiovascular disease among the elderly, initiate SYNTHROID at less than the full replacement dose see DOSAGE AND ADMINISTRATION and WARNINGS AND PRECAUTIONS. Atrial fibrillation is the most common of the arrhythmias observed with levothyroxine overtreatment in the elderly. Synthroid is prescribed in tablets that range from 25 to 300 mcg in strength and is usually taken once a day with a full glass of water (about 8 ounces) 30 to 60 minutes before breakfast for best adsorption into the body. Children can take the medicine if the tablet is crushed and put into about 1 to 2 teaspoons of water; do not store or delay giving this crushed pill suspension. Doctors often may have to slowly increase the dose; patients should not increase or decrease this medication themselves.

• Synthroid is the brand name for levothyroxine sodium, a synthetic thyroid hormone pill.
• Addition of levothyroxine therapy in patients with diabetes mellitus may worsen glycemic control and result in increased antidiabetic agent or insulin requirements.
• Tell your doctor about all your current medicines and any medicine you start or stop using.
• Closely monitor infants during the first 2 weeks of SYNTHROID therapy for cardiac overload and arrhythmias.
• Eltroxin is used for hashimoto’s disease, hypothyroidism, after thyroid removal, myxedema coma …

Past Medical History:

Converting hypothyroidism to the euthyroid state with Synthroid may increase the blood level of theophylline, and it may be necessary to change the dose of theophylline. Intravenous administration of epinephrine to patients with coronary artery disease may lead to complications ranging from difficulty in breathing to a heart attack. These complications may occur more frequently among patients also taking Synthroid. Anxiety is a fact of modern life for many women, but if you find yourself feeling seriously amped up and worried a lot, it could be a sign of an overactive thyroid and may indicate your Synthroid dosage is too high, Goldfarb says. Don’t suffer in silence; if you’re feeling unusually anxious, manic, or depressed after a few weeks on the meds, talk to your doctor.

hypothyroidism that has been managed on 112 mcg of SYNTHROID for the past 5 years.

The major pathway of thyroid hormone metabolism is through sequential deiodination. Approximately 80% of circulating T3 is derived from peripheral T4 by monodeiodination. The liver is the major site of degradation for both T4 and T3, with T4 deiodination also occurring at a number of additional sites, including the kidney and other tissues. Approximately 80% of the daily dose of T4 is deiodinated to yield equal amounts of T3 and reverse T3 (rT3).

• Euthyrox (levothyroxine) is used to treat hypothyroidism and to treat or prevent goiter.
• Levothyroxine is a medication that is generally taken for life to maintain normal thyroid function.
• In euthyroid patients, doses within the range of daily hormonal requirements are ineffective for weight reduction.

The recommended starting daily dosage of SYNTHROID in adults with primary, secondary, or tertiary hypothyroidism is based on age and comorbid cardiac conditions, as described in Table 1. For patients at risk of atrial fibrillation or patients with underlying cardiac disease, start with a lower dosage and titrate the dosage more slowly to avoid exacerbation of cardiac symptoms. Dosage titration is based on serum TSH or free-T4 see Important Considerations For Dosing. HypothyroidismSYNTHROID® (levothyroxine sodium) tablets, for oral use is indicated as a replacement therapy in primary (thyroidal), secondary (pituitary), and tertiary (hypothalamic) congenital or acquired hypothyroidism. Levothyroxine is a prescription medication that is used to treat hypothyroidism (underactive thyroid gland). Levothyroxine works by mimicking the activity of the natural hormone that is normally generated by the thyroid gland.

Your menstrual cycle is one of the many things regulated by your thyroid and one of the primary signs of hypothyroidism in women is an irregular period. Going on Synthroid should actually help you return to a normal cycle, which is a good thing, but may be surprising if you’ve gotten used to missed or delayed cycles. If your cycle is still wacky after a few months on the medication, talk to your doctor, Goldfarb says. Concurrent use of tyrosine-kinase inhibitors such as imatinib may cause hypothyroidism. Concurrent use of ketamine and SYNTHROID may produce marked hypertension and tachycardia.

The relative bioavailability of SYNTHROID tablets, compared to an equal nominal dose of oral levothyroxine sodium solution, is approximately 93%. T4 absorption is increased by synthroid appetite fasting, and decreased in malabsorption syndromes and by certain foods such as soybeans. In addition, many drugs and foods affect T4 absorption see DRUG INTERACTIONS. Thyroid hormones can increase the body’s metabolism and promote weight loss.

Synthroid is a prescription medicine used to treat hypothyroidism (low thyroid hormone). Levothyroxine is given when your thyroid does not produce enough of this hormone on its own. TSH should be monitored and SYNTHROID dosage adjusted during pregnancy. Following a 25-mcg dose change of levothyroxine, most patients had changes in TSH levels.

Measure and evaluate unbound (free) hormone and/or determine the free-T4 index (FT4I) in this circumstance. Pregnancy, infectious hepatitis, estrogens, estrogen-containing oral contraceptives, and acute intermittent porphyria increase TBG concentration. Nephrosis, severe hypoproteinemia, severe liver disease, acromegaly, androgens, and corticosteroids decrease TBG concentration. Familial hyper- or hypo-thyroxine binding globulinemias have been described, with the incidence of TBG deficiency approximating 1 in 9000. Synthroid should not be used to treat obesity or weight problems. Dangerous side effects or death can occur from the misuse of levothyroxine, especially if you are taking any other weight-loss medications or appetite suppressants.

Drug Interactions for Synthroid

If you’re having any heart issues at all, it’s important to call your doctor right away. They may or may not be related to your medications but you should get it checked out either way, she says. Synthroid is the brand name for levothyroxine sodium, a synthetic thyroid hormone pill. “Taking Synthroid replaces the hormones that your thyroid should be making but, for whatever reason, isn’t.” The signs and symptoms of overdosage are those of hyperthyroidism see WARNINGS AND PRECAUTIONS and Adverse Reactions.

Women taking daily doses of 1.6 mcg/kg or more had significantly lower bone mineral density levels at the ultradistal radius, midshaft radius, hip, and lumbar spine compared to controls. However, estrogen use appeared to negate the adverse effects of thyroid hormone on bone mineral density. Absorption of orally administered T4 from the gastrointestinal tract ranges from 40% to 80%. The majority of the SYNTHROID dose is absorbed from the jejunum and upper ileum.