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Compare Methimazole vs. Propylthiouracil

Head-to-head comparisons of medication uses, side effects, warnings, and more.

  • Methimazole
    Propylthiouracil
  • Methimazole
    Propylthiouracil

  • Summary of Methimazole vs. Propylthiouracil

    Summary for Antithyroid agent
    Prescription only

    Methimazole is an antithyroid medication. It's used to treat adults and children with hyperthyroidism (high thyroid hormone levels). This medication comes as a tablet. At the start, you usually take your dose by mouth 3 times a day. Then, your prescriber can work with you to find a dosing plan that works for you. Side effects can include rash, nausea, drowsiness, and headache. Although the brand name Tapazole is no longer sold, generic methimazole tablets are still available.

    Summary for Antithyroid
    Prescription only

    Propylthiouracil is used to treat an overactive thyroid (also known as hyperthyroidism). The medication is typically used if you can't tolerate methimazole or are preparing to undergo surgery. It can cause serious, life-threatening liver damage with symptoms that you need to look out for (e.g., itchiness and upper right abdominal pain). Other possible side effects include nausea, rash, joint pain, and loss of taste. Propylthiouracil is a first-choice treatment option during pregnancy, but shouldn't be used after the first trimester due to the risk of harm to mothers and unborn babies.

  • Indications of Methimazole vs. Propylthiouracil

    Indications for
    •Hyperthyroidism related to:
    •Graves’ disease
    •Overactive thyroid nodules that can't be treated with thyroid surgery or radioactive iodine
    •Preparation for thyroid surgery or radioactive iodine treatment
    Indications for
    •High thyroid hormone levels (hyperthyroidism) in people:
    •With Graves’ disease or other medical conditions who can’t take methimazole, receive thyroid surgery, or radioactive iodine treatment
    •Who are preparing to undergo thyroid surgery or radioactive iodine treatment

  • Pros and Cons of Methimazole vs. Propylthiouracil

    Pros and Const for Antithyroid agent
    Pros
    •Maintenance dose usually taken once a day
    •Might work better at improving thyroid hormone levels than propylthiouracil (PTU)
    •Less risk of serious liver damage than other antithyroid medications
    Cons
    •Need to get blood tests often to check thyroid hormone levels for dose adjustments
    •Might raise your risk of infection and easy bleeding
    •Not safe to take during the first trimester of pregnancy
    Pros and Const for Antithyroid
    Pros
    •Can be used during the first three months of pregnancy
    •First-choice medication for treating thyroid storm (life-threatening thyroid problem)
    •Available as a lower-cost generic
    Cons
    •Must be taken three times a day
    •More serious side effects than methimazole, like potential liver damage
    •Can raise your chance of infections

  • Common Side Effects of Methimazole vs. Propylthiouracil

    Common Side Effects for
    •Nausea (5-10%)
    •Vomiting (5-10%)
    •Stomach upset (5-10%)
    •Rash or hives (5-10%)
    •Itchiness (5-10%)
    Common Side Effects for
    •Nausea
    •Vomiting
    •Upper stomach pain or tenderness
    •Joint pain
    •Itching
    •Tingling sensation
    •Loss or change in taste
    •Loss of hair
    •Muscle pain
    •Headache
    •Nerve pain
    •Swelling (edema)
    •Dizziness

  • Warnings of Methimazole vs. Propylthiouracil

    Common Side Effects for
    •Harm to an unborn baby during the first trimester of pregnancy
    •Very low white blood cell count
    •Liver damage
    •Hypothyroidism (low thyroid hormone levels)
    •Thickening of blood vessels (vasculitis)
    Common Side Effects for
    •Liver damage
    •Harm to unborn babies
    •Weakened immune system
    •Low thyroid levels (hypothyroidism)
    •Blood vessel problems

  • Prices with our coupons for Methimazole vs. Propylthiouracil

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    Learn more about Propylthiouracil

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