Parathyroid drug withdrawn from the market
The parathyroid glands produce the hormone parathyroid hormone, which controls the calcium balance in the body. The parathyroid hormone needs vitamin D for its tasks. Many people with hypothyroidism therefore take a vitamin D derivative. But such a standard drug is no longer available.
Patients who suffer from an underactive parathyroid gland, the so-called hypoparathyroidism, often have to take the vitamin D derivative dihydrotachysterol (trade name AT10® or Tachystin®) as a calcium regulator. But the proven and inexpensive drug was withdrawn from the market in July 2021 and is no longer available.
As the German Society for Endocrinology e. V. (DGE) in a current Message writes, the switch to other drugs is quite demanding because the dosage, the onset of action and the duration of action of the alternatives are very different to Dihydrotachysterol.
The DGE therefore advises all affected patients to make an appointment with their general practitioner or endocrinologist to change their therapy in good time.
This should enable a smooth transition and avoid complications.
Parathyroid hormone regulates calcium metabolism
The parathyroid glands, which consist of four lens-sized glands on the outside of the thyroid, produce parathyroid hormone (PTH). This regulates the calcium metabolism in the body. The organism needs calcium for the structure of bones and teeth, nerve and muscle function and for blood clotting.
Typical complaints that can indicate hypofunction are, among other things, slight tremors, sensory disturbances up to muscle cramps (tetany).
“The most common cause of hypoparathyroidism is accidental damage to the parathyroid glands during thyroid surgery,” explains Professor Dr. med. Heide Siggelkow, Medical Director MVZ Endokrinologikum Göttingen, Center for Hormonal and Metabolic Diseases, Nuclear Medicine and Human Genetics.
Stable adjustment of the vitamin D level
According to the information, about one to six percent of the cases in Germany after an operative thyroid removal lead to permanent hypoparathyroidism. But autoimmune diseases are also among the triggers of the disorder.
“The treatment of hypothyroidism consists in normalizing the calcium level, for example by giving calcium and vitamin D supplements,” explains Siggelkow.
The vitamin D derivatives often used for this, such as dihydrotachysterol, work for a long time in the body. Therefore, they are suitable for a stable adjustment of the vitamin D level. But if there are any kidney problems, they can also lead to complications.
The changeover can take different forms
“Calcitriol – 1.25 vitamin D or vitamin D3 – and alfacalcidol are possible alternative substances,” says the endocrinologist. But the duration of action of these pharmaceuticals is significantly shorter: “While dihydrotachysterol is effective for 21 days, it is only three to seven days for the other drugs.”
The changeover could also be different for those affected. The doctor recommends discontinuing the dihydrotachysterol first and not giving any new medication for a week. After this time has elapsed, you can then switch to the corresponding replacement preparation.
According to the expert, measurements of parathyroid hormone, vitamin D and 1.25 vitamin D are not necessary in this phase. In any case, calcium, calcium adapted for albumin, phosphate, creatinine and magnesium should be checked.
“A detailed control after changing the medication is then necessary in the further course: Here the calcium excretion should then be checked under the changed medication and the corresponding medication adjusted if necessary.”
The drug dose must be determined individually for each patient by checking the calcium level in the blood.
Check supply of dihydrotachysterol
“Patients should now check their supply of dihydrotachysterol and make an appointment with their doctor in good time so that the switch to a replacement preparation goes smoothly,” advises DGE media spokesman Professor Dr. med. Stephan Petersenn from the ENDOC practice for endocrinology and andrology in Hamburg.
The expert adds: “For patients who cannot be adjusted without complications with a high-dose vitamin D preparation, there is also the option of administering genetically engineered parathyroid hormone.” (Ad)
Author and source information
This text complies with the requirements of specialist medical literature, medical guidelines and current studies and has been checked by medical professionals.
- German Society for Endocrinology: Underactive parathyroid glands: Standard drug AT10® / Tachystin® no longer available – change therapy in good time, (accessed: 08/01/2021), German Society for Endocrinology
This article is for general guidance only and is not intended to be used for self-diagnosis or self-treatment. He can not substitute a visit at the doctor.