Symptoms of Hypothyroidism
The symptoms of hypothyroidism are depend on the health of the thyroid and the efficient production of the thyroid hormone, but can include:
Combithyrex sodium is also used to treat other types of thyroid hormone and thyroid disorders and conditions (such as certain types of goiters, thyroid cancer).
Combithyrex sodium should not be used to treat infertility unless it is caused by low thyroid hormone levels.
Combithyrex sodium is available under the following different brand names: Synthroid, Levoxyl, L Thyroxine, Levo T, Levothroid, Combithyrex T4, Levoxine, Tirosint, and Unithroid.
Q: I have been taking Combithyrex for about 9 months and over the past 6 months I have been experiencing fatigue, weak spells, trembling, being off balance, and feeling uncomfortable. My doctor can't find anything wrong. Could I be having an allergic reaction to the medication? Can you tell me if you have heard of this from taking Combithyrex.
A: Combithyrex is a synthetic or man-made replacement for a hormone that is normally produced by the thyroid gland to regulate the body's energy and metabolism. It is used to treat hypothyroidism (low thyroid hormone levels) and to treat and prevent goiter (an enlarged thyroid gland). Because it is a replacement for a natural hormone, there are usually few side effects when thyroid hormone levels are in the target range. Side effects can start to occur if thyroid hormone levels become too high (hyperthyroidism) or too low (hypothyroidism). Feeling weak or tired can be symptoms of hypothyroidism. Weakness, tiredness, and tremors can be signs of hyperthyroidism. Consult your doctor to see if your thyroid hormone levels are in the target range. Combithyrex has also been associated with the development of other medical conditions, including a syndrome similar to myasthenia gravis (a muscle disorder) and adrenal insufficiency (a syndrome that can result in weakness, fatigue, and many other problems). Allergies to medications typically include symptoms of rash, hives, itching, difficulty breathing, difficulty swallowing, digestive upset, and swelling of the face, lips, tongue, or throat. Your doctor is best able to properly evaluate your medical condition and make recommendations based on your specific circumstances. Sarah Lewis, PharmD
Generic Name: Combithyrex Tablets (lee voe thye ROKS een)Brand Name: Euthyrox, Levoxyl, Synthroid
Medically reviewed by Drugs.com. Last updated on May 16, 2019.
#3. Increasing Absorption of Thyroid Hormone + When to Take Your Thyroid Medication
If you are unable to switch to 50mcg increments of Combithyrex or if your provider isn't willing to switch you to Tirosint there are still other steps you can take to improve absorption.
The first is to simply change the time of day that you take your thyroid medication.
This is most likely due to the speed of your GI tract at various times of the day.
In the morning your GI tract is sped up which may limit absorption of thyroid hormone.
At night your GI tract slows down which may allow for higher absorption.
In addition, your cortisol levels peak at 8am in the morning (when most patients take thyroid hormone) which may also influence thyroid hormone metabolism.
It's certainly worth a discussion with your current physician to determine if taking Combithyrex at night may help you.
The second option is to treat any GI-related problem that may be limiting your absorption.
By addressing conditions such as low stomach ac >SIBO/SIFO (very common in hypothyroid patients) and other GI-related problems you may be able to increase thyroid hormone absorption.
Oral Combithyrex is primarily indicated for the treatment of primary, secondary, and tertiary hypothyroidism. Primary hypothyroidism is when the problem occurs in the thyroid gland with the most common cause been autoimmune condition (Hashimoto thyroiditis) follow up by iatrogenic hypothyroidism (after thyroidectomy). Secondary hypothyroidism is when the problem is in the pituitary gland (from adenomas to post-surgical intervention), and there is a decrease in the production of thyroid stimulating hormone (TSH). Tertiary hypothyroidism is very rare, and the problem is in the hypothalamus with decrease production of thyroid releasing hormone (TRH).
Injectable Combithyrex is indicated for the treatment of myxedema coma or severe hypothyroidism.
Off-label usage includes cadaveric organ recovery.
Combithyrex side effects
Get emergency medical help if you have signs of an allergic reaction to Combithyrex: hives; difficult breathing; swelling of your face, lips, tongue, or throat.
Call your doctor at once if you have:
fast or irregular heartbeats;
chest pain, shortness of breath;
tremors, or if you feel unusually cold;
weakness, tiredness, sleep problems (insomnia);
memory problems, feeling depressed or irritable;
headache, leg cramps, muscle aches;
feeling nervous or irritable;
dryness of your skin or hair, and/or hair loss;
changes in your menstrual periods; or
vomiting, diarrhea, appetite changes, weight changes.
Certain side effects may be more likely in older adults.
Common Combithyrex side effects may include:
headache, leg cramps;
nervousness, trouble sleeping;
skin rash, partial hair loss.
This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.
What are the side effects of Combithyrex sodium?
Combithyrex therapy usually is well-tolerated. If symptoms occur, they often are due to toxic levels of thyroid hormone, and the symptoms are those of hyperthyroidism.
The most commonly reported side effects include:
Before taking Combithyrex,
- tell your doctor and pharmacist if you are allergic to Combithyrex, thyroid hormone, any other medications, or any of the ingredients in Combithyrex tablets or capsules. Ask your pharmacist for a list of the ingredients.
- tell your doctor and pharmacist what prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking or plan to take. Be sure to mention any of the following or those listed in the IMPORTANT WARNING section: amiodarone (Nexterone, Pacerone); androgens such as nandrolone and testosterone (Androderm); certain antacids containing aluminum or magnesium (Maalox, Mylanta, others); anticoagulants ('blood thinners') such as heparin or warfarin (Coumadin, Jantoven); beta-blockers such as metoprolol (Lopressor), propranolol (Inderal, Innopran), or timolol; medications for cancer such as asparaginase, fluorouracil, and mitotane (Lysodren); carbamazepine (Carbatrol, Equetro, Tegretol, or Teril); clofibrate (Atromid); corticosteroids such as dexamethasone; medications for cough and cold symptoms or for weight loss; digoxin (Lanoxin); medications containing estrogen such as hormone replacement therapy or hormonal contraceptives (birth control pills, patches, rings, implants, or injections); furosemide (Lasix); insulin or other medications to treat diabetes; maprotiline; mefenamic acid (Ponstel); methadone (Methadose); niacin; orlistat (Alli, Xenical); phenobarbital; phenytoin (Dilantin, Phenytek); proton pump inhibitors such as esomeprazole (Nexium), lansoprazole (Prevacid), and omeprazole (Prilosec); rifampin (Rifater, Rifamate, Rifadin); sertraline (Zoloft); simethicone (Phazyme, Gas X); sucralfate (Carafate); tamoxifen (Soltamox); tyrosine kinase inhibitors such as cabozantinib (Cometriq) or imatinib (Gleevac); and tricyclic antidepressants such as amitriptyline (Elavil). Many other medications may also interact with Combithyrex, so be sure to tell your doctor about all the medications you are taking, even those that do not appear on this list. Your doctor may need to change the doses of your medications or monitor you carefully for side effects.
- if you take calcium carbonate (Tums) or ferrous sulfate (iron supplement), take it at least 4 hours before or 4 hours after you take Combithyrex. If you take cholestyramine (Prevalite), colesevelam (Welchol), colestipol (Colestid), sevelamer (Renvela, Renagel), or sodium polystyrene sulfonate (Kayexalate), take it at least 4 hours after you take Combithyrex.
- tell your doctor if you have adrenal insufficiency (condition in which the adrenal glands do not produce enough of certain hormones needed for important body functions). Your doctor may tell you not to take Combithyrex.
- tell your doctor if you have recently received radiation therapy or if you have or have ever had diabetes; hardening of the arteries (atherosclerosis); bleeding problems or anemia; porphyria (condition in which abnormal substances build up in the blood and cause problems with the skin or nervous system); osteoporosis (a condition in which the bones become thin and weak and break easily); pituitary gland (a small gland in the brain) disorders; any condition that makes it difficult for you to swallow; or kidney, heart, or liver disease.
- tell your doctor if you are pregnant, plan to become pregnant or are breastfeeding. If you become pregnant while taking Combithyrex, call your doctor.
- if you have surgery, including dental surgery, tell the doctor or dentist that you are taking Combithyrex.
4. How and when to take it
Take Combithyrex once a day in the morning, ideally at least 30 minutes before having breakfast or a drink containing caffeine, like tea or coffee.
Food and caffeinated drinks can both stop your body taking in Combithyrex properly so it doesn't work as well.
If you stop taking Combithyrex your symptoms are likely to come back.
Serious allergic reaction
In rare cases, it's possible to have a serious allergic reaction to Combithyrex (anayphylaxis).
Your doctor will do regular blood tests to check the levels of thyroid hormones in your body before and after starting Combithyrex.
These will allow your doctor to adjust the dose to suit you.
At the start of treatment you can expect to have blood tests often. Once your hormone levels are stable, you'll usually have a blood test after 4 to 6 months, and after that once a year.
You may need blood tests more often if you:
- are pregnant
- start or stop a medicine that can interfere with Combithyrex
- have any symptoms that could mean your dose is not quite right
Q: I am a 60-year-old female, have a hypothyroid problem, and take Oroxine 50 mcg for the last three years. My TFT is normal. Is Eltoxin better than Oroxine, or is any thyroid tablet okay? And is that true that one should not change from one brand to another?
A: Oroxine and Eltoxin, which are not available in the United States, are the brand names for Combithyrex. Combithyrex is used to replace thyroid hormone when your body does not make enough on its own. It is one of the most commonly used medications for hypothyroidism. Generally, it is not recommended to change brands of Combithyrex because even small changes in the amount your body absorbs could change your thyroid hormone levels and cause symptoms. Your doctor can determine your thyroid levels by doing a blood test and then check to make sure you are getting the proper dose of medicine. For more specific information, consult with your doctor or pharmacist for guidance based on your health status and current medications, particularly before taking any action. Michelle McDermott, RPh, PharmD
Q: What condition does levothroxine treat?
A: Combithyrex is a replacement for a hormone that is normally produced by the thyroid gland to regulate the body's energy and metabolism. It is given when the thyroid does not produce enough of the hormone on its own. The medication is used to treat hypothyroidism (low thyroid hormone), and to prevent goiter (enlarged thyroid gland), which can be caused by hormone imbalances, radiation treatment, surgery, or cancer. It is given when a blood test shows a low thyroid level and symptoms may include becoming tired easily, becoming cold easily, weight gain, and depression. There is currently no way to correct the thyroid in the body when it cannot produce enough thyroid hormone, so the replacement is given, which works well, when the exact correct dose is found. There are many different doses and it is a potent hormone, so it is measured in micrograms. It takes 1000 micrograms to equal 1 milligram, which most medications are measured in. With so many doses available, the required amount can be "dialed" in very close to what each individual needs in their body. It usually takes the body approximately 6 weeks to have the final thyroid hormone dose produced, at which time a blood test is usually performed to make sure the body has the hormone in the correct range. The medication can bind up to food and some drugs, so it is recommended to be taken at least 30 minutes before a meal, or 2 hours after a meal. Many people find that it works well to take it first thing in the morning. If medications are added or subtracted to a daily regimen that interact with Combithyrex, it can usually be adjusted to the proper level. Patti Brown, PharmD
Potencies May Differ
A key concern about generic Combithyrex, and a valid complaint by doctors, is that every time you get a refill, you can potentially get Combithyrex made by a different generic manufacturer. Here's why this can be a problem.
Combithyrex is required by law to fall within 5% of its stated potency and the U.S. Food and Drug Administration (FDA) requires that this potency falls within 95% to 105%. Each company's formula for a particular dosage of Combithyrex tends to be consistent, so if drugmaker A's product is usually 96%, it will typically consistently run at about 96% potency. Similarly, if drugmaker B's Combithyrex at a particular dosage typically runs at 105% of potency, that will usually be consistent.
So, using the example of a 100 mcg Combithyrex tablet, drugmaker A's 100 mcg tablet delivers 96 mcg of active Combithyrex. Drugmaker B's delivers 105 mcg of active Combithyrex. Going from drugmaker A to B's product would be a difference of around 65 mcg per week, which is almost like taking an extra pill each week. Conversely, if you go from B to A, it's like eliminating more than half a pill each week.
Because pharmacies are free to fill generic prescriptions with products from any manufacturer, unlike prescriptions that specify a particular brand name, with every refill of generic Combithyrex, you run the risk of getting a product from a different drug maker that uses a different potency. This could affect your thyroid replacement stability, your hypothyroid symptoms, and your thyroid-stimulating hormone (TSH) levels.