A Guide to PTU Medication
Propylthiouracil is a treatment, taken as a tablet, used to treat those with an overactive thyroid (otherwise known as hyperthyroidism). It’s quite a mouthful to say and is often simply referred to as PTU! It is considered a ‘wonder-drug’ by many, helping them to manage their hyperthyroidism and experience alleviated symptoms.
What is PTU Medication and how does it work?
Taken orally, by tablet, PTU is used to manage an overactive thyroid, known as hyperthyroidism (or sometimes referred to as thyrotoxicosis). Hyperthyroidism is when the thyroid produces too much of the thyroid hormones. This can be troublesome and cause a wide range of issues for the sufferer.
The thyroid gland (situated at the front of the neck) is responsible for producing hormones which have various roles in your health, including regulating your heart rate and body temperature. If you have an overproduction of these hormones you can get unpleasant symptoms, but it can also be quite dangerous.
Signs that you may have hyperthyroidism include:
- Mood swings and changes
- Anxiety and irritability
- Insomnia
- Heat sensitivity and difficulty regulating your body temperature
- Fatigue and lack of energy
- Muscle weakness
- Tachycardia or palpitations (and irregular or unusually fast heart rate)
- Trembling, shaking or twitching
- Unexplained weight loss
- A goiter (this is a swelling in your neck caused by the oversized thyroid gland)
Anyone can experience hyperthyroidism but it is much more common in women, and typically presents between age 20 and 40. There is more than one reason behind hyperthyroidism. It’s important to pin down the cause.
The main causes of hyperthyroidism are:
- Graves’ disease: This is the most common cause of
hyperthyroidism, causing about three quarters of all cases. This is an
autoimmune condition where your immune system effectively gets confused
and both attacks and damages the thyroid gland. - Thyroid nodules: Small lumps, known as nodules,
can form on the thyroid. This creates additional thyroid tissue,
enabling the thyroid to produce more hormones than are needed, resulting
in elevated levels. - Medication: Certain medications, typically those
used to treat an arrhythmia (irregular heartbeat), such as amiodarone,
can cause hyperthyroidism.
Propylthiouracil (PTU) is one medication that can be used to manage hyperthyroidism. It has a way of working that isn’t too dissimilar to other thyroid medications, like methimazole.
To understand how PTU works, you need to understand how the thyroid works. In a nutshell, two of the thyroid hormones made in the thyroid gland are called thyroxine (T4) and triiodothyronine (T3). These hormones can only be made with the combination of iodine, an enzyme called peroxidase, and a protein called thyroglobulin.
PTU effectively blocks iodine and peroxidase from working with thyroglobulin in the way it would usually. It therefore reduces the amount of T3 and T4 which are produced.
PTU also does something else to help. T3 is the more active form of thyroid hormone. Our bodies convert T4 into T3. PTU also interferes with this conversion process meaning you have less production of the more active and potent T3 hormones.
PTU as a medication for hyperthyroidism has actually been around for a very long time. It was first approved for use in the USA in 1947.
Does PTU have side effects?
All medications come with potential side effects. It’s important to understand why you are taking a medication so that you can balance the benefits versus the risks.
Common side effects are generally mild and tend to be related to the skin. For example, common side effects include itching, rashes, hives, changes to skin pigmentation and unusual hair loss.
Other side effects are quite varied and include: joint and muscle pains and aches, headache, swelling, nausea and vomiting, heartburn, loss of taste and numbness.
Very rarely there are more serious side effects of PTU. These include agranulocytosis (a reduction in the number of white blood cells in your blood) and thrombocytopenia (decrease in blood platelets).
What is the dose for PTU?
Typically, when your doctor advises that you start taking PTU you will be prescribed 300mg per day which is usually divided into three doses which are taken 8 hours apart. If your goiter is particularly large, and your hyperthyroidism particularly marked, you may be prescribed an initial dose as high as 900mg per day, again split into three doses. Once your hyperthyroidism is more under control, the dose is typically dropped to around 100-150mg per day.
Can anyone take PTU?
You should only take PTU if you have been diagnosed with hyperthyroidism and been prescribed PTU by your physician.
Most patients with hyperthyroidism can take PTU safely, however there are some interactions with other medications. PTU has been known to increase the effect of certain blood thinners, such as warfarin. The opposite occurs with some beta blockers, such as propranolol with the PTU effectively eliminating the beta blocker, weakening its effectiveness. There are also a few other medications which can interact with PTU, such as digoxin and theophylline.
Where to get your PTU medication
At the International Pharmacy we stock a very broad range of doses of PTU tablets. We ship internationally, and we’re able to fulfil your prescription.