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Methimazole

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User Ratings

Out of 10

Satisfaction

4.5

3.1 Effectiveness

6.1 Side Effects

4.7 Holistic Benefits

RateADrug users have reported 9 Methimazole side effects and 4 Methimazole benefits.

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Treatment Information

Description | Uses & Side Effects | Warnings

There is currently no information to display in this section. RateADrug provides information about drugs and supplements though a wiki format provided by researchers, health care providers and others. We encourage you to add to this description by clicking on the button below.

Common Uses:

Methimazole is indicated in the medical treatment of hyperthyroidism. Long-term therapy may lead to remission of the disease. Methimazole may be used to ameliorate hyperthyroidism in preparation for subtotal thyroidectomy or radioactive iodine therapy. Methimazole is also used when thyroidectomy is contraindicated or not advisable.

Off Label Uses:

Currently there are no known off label uses for Methimazole.

Side Effects:
Methimazole is generally well-tolerated with side effects occurring in three out of every 100 patients.

The most common side effects are related to the skin and include rash, itching, hives, abnormal hair loss, and skin pigmentation. Other common side effects are swelling, nausea, vomiting, heartburn, loss of taste, joint or muscle aches, numbness and headache.

Less common but more serious side effects include a decrease in white blood cells (agranulocytosis) and blood platelets (thrombocytopenia). Symptoms and signs of agranulocytosis include infections of the throat, the gastrointestinal tract, and skin with an overall feeling of illness and fever. Since platelets are important for the clotting of blood, thrombocytopenia may lead to problems with excessive bleeding. Hepatitis and death of liver cells (hepatic necrosis) have rarely been associated with methimazole.

Cautions / Warnings:

Methimazole may cause drowsiness, dizziness, or lightheadedness. These effects may be worse if you take it with alcohol or certain medicines. Use Methimazole with caution. Do not drive or perform other possibly unsafe tasks until you know how you react to it.

Lab tests, including thyroid and liver function tests, complete blood cell counts, and blood clotting tests (eg, PT, INR), may be performed while you use Methimazole. These tests may be used to monitor your condition or check for side effects. Be sure to keep all doctor and lab appointments.

Methimazole has been shown to cause harm to the fetus. If you think you may be pregnant, contact your doctor. You will need to discuss the benefits and risks of using Methimazole while you are pregnant. Methimazole is found in breast milk. Do not breast-feed while taking Methimazole .

Agranulocytosis is potentially a serious side effect. Patients should be instructed to report to their physicians any symptoms of agranulocytosis, such as fever or sore throat. Leukopenia, thrombocytopenia, and aplastic anemia (pancytopenia) may also occur. The drug should be discontinued in the presence of agranulocytosis, aplastic anemia (pancytopenia), hepatitis, or exfoliative dermatitis. The patient's bone marrow function should be monitored.

Drug Interactions:
Drug interactions with Methimazole include the following:

Anticoagulants (oral) - The activity of oral anticoagulants may be potentiated by anti-vitamin-K activity attributed to Methimazole.

ß-adrenergic blocking agents - Hyperthyroidism may cause an increased clearance of beta blockers with a high extraction ratio. A dose reduction of beta-adrenergic blockers may be needed when a hyperthyroid patient becomes euthyroid.

Digitalis glycosides - Serum digitalis levels may be increased when hyperthyroid patients on a stable digitalis glycoside regimen become euthyroid; a reduced dosage of digitalis glycosides may be required.

Theophylline - Theophylline clearance may decrease when hyperthyroid patients on a stable theophylline regimen become euthyroid; a reduced dose of theophylline may be needed.

View / Add User Comments (14)

Methimazole Comments

27 Feb 2013

I began the Methimazole in September of 2012. The first week was bad. Ups and downs and really bad headaches but then the headaches stopped and my energy level returned and things seemed to level out. My second lab that was drawn showed normal levels - then into the fourth month I began having that racing feeling with my heart and was so tired and had the shakes again and could barely stay awake and when I did sleep I never felt rested. My immediate thought was , this medication needs to be decrease and lo and behold I was right. The last labs drawn on Feb 14, 2013 showed the levels to be low ...so my DOC decreased the Methimazole to 10 mg per day half in the morning, half at night and within two days I began getting ready bad headaches. I was told this would happen until is all levels out again and my energy returns. I just do not know what to think, I hate medication and have not been sick in 22 years. When my blood pressure was out of control this past September it was my first ER visit in years and they are yelling HEART and I am saying NO THYROID ... do I know my own body or what? Endo wanted to yank ti out or do RA Iodine and I said " When pigs fly" My DOC is so great and he said "Look I know you are Holistic and do not like drugs but please try the Methimazole and if it does not agree with you I will take you off it " I trust my DOC so I took it for the four plus months. It's only been two days since the decrease and the headache from hell is what i have. Can anyone please explain that to me?

—Posted by Anonymous

13 Nov 2012

I am on my second week of taking these meds. Its worked great so far and hoping it continues to improve. I've been dealing with the symptoms (muscle/weight loss, shakes, memory loss - at night body is basically paralyzed from neck down) for about 3-4 months. I don't know what the normal symptoms are, and I've read that some have dealt with it for awhile. If it is anything like what I had, I do hope you find relief soon. The quality of life this has given back to me thus far is incredible. I haven't noticed any side effects so far, however it has only been 2 weeks. I read some deal with insomnia, I've had insomnia issues as far back as I can remember so not sure it changes anything for me. Bottom line for me is that it lets me hold my wife and play with my kids again.

—Posted by Cas A

07 Sep 2012

My major problem with Methimazole, which I have taken for the past 6 months, is severe insomnia which makes me so very exhausted during the day. I have never been a very good sleeper, but this is ridiculous! I have also lost half of my hair. I am having blood work next week and a follow-up with my endocrinologist a week later and hope to get some answers. To be fair, this drug has made my thyroid numbers fall in to the normal range.

—Posted by Tired Lady

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Brands	Effectiveness	Holistic Benefits	Side Effects	Number of Ratings
Tapazole	5.5	3.3	2.94	4
Propylthiouracil	5	3.68	5.12	3
Methimazole	4.5	5.09	4.51	4
Carbimazole	3.35	3.91	5.7	72
Liothyronine Sodium	0	0	0	0

View All	About these Scores
	Choose a condition to compare treatments based on user feedback. You can sort by Effectiveness, Holistic Benefits or Side Effects RateADrug user scores, or the number of Ratings. Scores gain significance with the number of ratings, so please share your experiences - rate your drug! Close

Effectiveness of Methimazole by Condition

Click on a condition to view RateADrug.com users ratings

Hyperthyroidism

Hypothyroidism

- - - - - - - - - - - - - - - - -

Effectiveness on "Hyperthyroidism"

About these Results
Out of 100% of people surveyed, these results show the distribution in percentages of how users rate the effectiveness of their medication. Click on the various conditions to see how the effectiveness ratings change. Close

Not at all

Mildly

Moderately

Very

Extremely

How effective is Methimazole?

Reported Changes in Health and Well-Being

Since taking Methimazole, RateADrug survey participants noticed these changes in their health:

Effect on:	Much Worse	Worse	No Change	Better	Much Better
Appetite	7.7%	15.4%	69.2%	3.8%	3.8%
Balance/Equilibrium	11.1%	11.1%	66.7%	7.4%	3.7%
Blood Pressure	0%	4%	76%	12%	8%
Breathing	4%	4%	84%	8%	0%
Confidence	7.7%	3.8%	73.1%	7.7%	7.7%
Coordination/Motor Skills	11.1%	18.5%	55.6%	11.1%	3.7%
Digestion	7.7%	11.5%	69.2%	11.5%	0%
Emotional Well-being	14.8%	3.7%	48.1%	22.2%	11.1%
Energy	14.8%	29.6%	29.6%	22.2%	3.7%
Eyesight	3.8%	11.5%	76.9%	3.8%	3.8%
Memory	11.5%	7.7%	57.7%	15.4%	7.7%
Mental Clarity	11.1%	11.1%	59.3%	11.1%	7.4%
Pain	11.1%	0%	77.8%	7.4%	3.7%
Patience	11.5%	7.7%	53.8%	23.1%	3.8%
Sexual Health	14.8%	3.7%	74.1%	3.7%	3.7%
Skin Complexion	3.8%	11.5%	80.8%	3.8%	0%
Sleep	26.9%	11.5%	42.3%	7.7%	11.5%
Stress Level	7.7%	7.7%	50%	19.2%	15.4%

About these Scores
Out of 100% of people surveyed, these results show the distribution in percentages of negative or positive changes in health and well-being experienced by users for all of the categories listed. Close

Commonly Reported Methimazole Side Effects

RateADrug survey participants experienced these commonly reported side effects:

Effect on:	None	Mild	Moderate	Strong	Severe
Anxiety	88.9%	0%	11.1%	0%	0%
Blurred Vision	77.8%	11.1%	11.1%	0%	0%
Change in Weight	0%	25%	25%	25%	25%
Chills	33.3%	0%	33.3%	33.3%	0%
Cold Symptoms	88.9%	11.1%	0%	0%	0%
Confusion	88.9%	11.1%	0%	0%	0%
Coordination / Balance Problems	25%	25%	0%	25%	25%
Depression	88.9%	11.1%	0%	0%	0%
Dizziness	69.2%	15.4%	7.7%	3.8%	3.8%
Drowsiness	53.8%	19.2%	11.5%	11.5%	3.8%
Fatigue	53.8%	7.7%	15.4%	7.7%	15.4%
Gas	77.8%	22.2%	0%	0%	0%
Headache	54.5%	31.8%	9.1%	0%	4.5%
Hives	33.3%	0%	33.3%	0%	33.3%
Insomnia	66.7%	22.2%	0%	0%	11.1%
Irregular Heartbeat	77.8%	11.1%	11.1%	0%	0%
Itching	72.7%	18.2%	4.5%	4.5%	0%
Joint Swelling	81.8%	18.2%	0%	0%	0%
Mood Swings	88.9%	11.1%	0%	0%	0%
Muscle / Joint Pain	54.5%	18.2%	18.2%	4.5%	4.5%
Muscle Cramping	55.6%	0%	44.4%	0%	0%
Nausea	25%	25%	25%	25%	0%
Sexual Dysfunction	77.8%	11.1%	11.1%	0%	0%
Skin Rash	75%	18.8%	6.2%	0%	0%
Sore Throat	81.8%	9.1%	4.5%	4.5%	0%
Stomach Ache	88.9%	11.1%	0%	0%	0%

About these Scores
Out of 100% of people surveyed, these results show the distribution in percentages of the severity of side effects experienced by users. Scores gain significance with the number of ratings, so please share your experiences - rate your drug! Close

Less Commonly Reported Methimazole Side Effects

RateADrug survey participants experienced less commonly reported side effects:

Effect on:	None	Mild	Moderate	Strong	Severe
Burning Sensation	95.5%	0%	0%	4.5%	0%
Constipation	33.3%	0%	33.3%	0%	33.3%
Hair Loss	59.1%	22.7%	9.1%	4.5%	4.5%
Headache	33.3%	33.3%	33.3%	0%	0%
Insomnia	0%	0%	0%	100%	0%
Loss of Sense of Smell	90.9%	9.1%	0%	0%	0%
Muscle / Joint Pain	25%	0%	0%	50%	25%
Numbing Sensation	95.5%	4.5%	0%	0%	0%
Reduced Libido	90.9%	0%	0%	0%	9.1%
Skin Inflammation	50%	0%	50%	0%	0%
Tingling Sensations	33.3%	66.7%	0%	0%	0%

About these Scores
Out of 100% of people surveyed, these results show the distribution in percentages of the severity of side effects experienced by users. Scores gain significance with the number of ratings, so please share your experiences - rate your drug! Close

Episodes since taking Methimazole

Since taking Methimazole Rate a Drug survey participants reported these episodes:

Fall

10.3%

About these Results
Out of 100% of people surveyed, these results show the percentage of users who have experienced any of these episodes while taking their medication. Close

How does your experience compare with other Methimazole users?

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User Comments about Methimazole

27 Feb 2013	I began the Methimazole in September of 2012. The first week was bad. Ups and downs and really bad headaches but then the headaches stopped and my energy level returned and things seemed to level out. My second lab that was drawn showed normal levels - then into the fourth month I began having that racing feeling with my heart and was so tired and had the shakes again and could barely stay awake and when I did sleep I never felt rested. My immediate thought was , this medication needs to be decrease and lo and behold I was right. The last labs drawn on Feb 14, 2013 showed the levels to be low ...so my DOC decreased the Methimazole to 10 mg per day half in the morning, half at night and within two days I began getting ready bad headaches. I was told this would happen until is all levels out again and my energy returns. I just do not know what to think, I hate medication and have not been sick in 22 years. When my blood pressure was out of control this past September it was my first ER visit in years and they are yelling HEART and I am saying NO THYROID ... do I know my own body or what? Endo wanted to yank ti out or do RA Iodine and I said " When pigs fly" My DOC is so great and he said "Look I know you are Holistic and do not like drugs but please try the Methimazole and if it does not agree with you I will take you off it " I trust my DOC so I took it for the four plus months. It's only been two days since the decrease and the headache from hell is what i have. Can anyone please explain that to me? —Posted by Anonymous Respond Display Name: Email: (Required) Notify me of new comments Email me monthly survey results Sending... I agree to the Terms of Use
13 Nov 2012	I am on my second week of taking these meds. Its worked great so far and hoping it continues to improve. I've been dealing with the symptoms (muscle/weight loss, shakes, memory loss - at night body is basically paralyzed from neck down) for about 3-4 months. I don't know what the normal symptoms are, and I've read that some have dealt with it for awhile. If it is anything like what I had, I do hope you find relief soon. The quality of life this has given back to me thus far is incredible. I haven't noticed any side effects so far, however it has only been 2 weeks. I read some deal with insomnia, I've had insomnia issues as far back as I can remember so not sure it changes anything for me. Bottom line for me is that it lets me hold my wife and play with my kids again. —Posted by Cas A Respond Display Name: Email: (Required) Notify me of new comments Email me monthly survey results Sending... I agree to the Terms of Use
07 Sep 2012	My major problem with Methimazole, which I have taken for the past 6 months, is severe insomnia which makes me so very exhausted during the day. I have never been a very good sleeper, but this is ridiculous! I have also lost half of my hair. I am having blood work next week and a follow-up with my endocrinologist a week later and hope to get some answers. To be fair, this drug has made my thyroid numbers fall in to the normal range. —Posted by Tired Lady Respond Display Name: Email: (Required) Notify me of new comments Email me monthly survey results Sending... I agree to the Terms of Use
01 Sep 2012	I am writing on behalf of my mother who is suffering from HYPERthyroidism. She feels that this medication is treating only her lab numbers. Regardless of where the numbers are,(normal now, per last draw of May 2012) she feels "not well". She is out out of the thyroid storm (had one in summer 2007), i.e. not always perspiring or tachychardic, BUT the quality of life has changed for the worse PERMANENTLY. She has lost more than half of her muscle mass and looks much older that her 77. The change in appearance (with the beginning of the disease) was overnight - suddenly darker eyebrows, wrinkled face, loss of muscle tone in the arms - followed by a muscle tear from simple outstretch of the arm. To this day, fast-growing fingernails. Dropping untencils, cups, plates. Memory and cognitive deficits. Quite devastating. At this point I don't know whether it is the methimazole's fault or her own age-related dementia... —Posted by Xopollo Respond Display Name: Email: (Required) Notify me of new comments Email me monthly survey results Sending... I agree to the Terms of Use
21 Dec 2011	I think it is causing insomnia, but not sure. I have not been able to sleep since taking the nuclear meds to kill my thyroid. This is the only new medication that I have taken since then . I started it 2 days after the nuclear medicine. I'm also taking carvedilol 12.5 mg 2 times / day. I've been experiencing joint & muscle pain but have had that before taking any medication. because I'm not sleeping and shaking, I was put on .5 mg of xanax/ 3 times / day. I have severe dry mouth and eyes. I don't know if all of this is side effects of different drugs or from the nuclear treatment, but I have rarely had dry mouth, blurred vison, or headaches and I do now. I have never had insomnia till now. I'm frustrated with taking medicine. I don't think that any of it is out weighing the side effects. —Posted by Anonymous Respond Display Name: Email: (Required) Notify me of new comments Email me monthly survey results Sending... I agree to the Terms of Use