How Do Tyrosine Hydroxylase Inhibitors Work?
Tyrosine hydroxylase inhibitors (THIs) are a class of drugs that inhibit the production of catecholamines. Catecholamines like adrenaline, noradrenaline, and dopamine help the body respond to stress or fright. THIs mainly work by inhibiting an enzyme known as tyrosine hydroxylase (TH).
To get an idea about THIs, it is essential to first know about the enzyme TH and its function. TH is an enzyme involved in the production of catecholamines. It also maintains the level of catecholamines in the body. TH is responsible for converting an amino acid L-tyrosine into L-DOPA (dihydroxyphenylalanine). L-DOPA is a precursor for dopamine, which in turn is a precursor for other chemical messengers (neurotransmitters), such as noradrenaline and adrenaline.
By inhibiting TH, THIs prevent the production of neurotransmitters. Accordingly, they would be beneficial in conditions with excess release of adrenaline and noradrenaline.
How Are Tyrosine Hydroxylase Inhibitors Used?
As THIs prevent the release of excess adrenaline and noradrenaline, they are mainly used to treat:
- Pheochromocytoma (a rare tumor in the adrenal glands caused by the excess release of catecholamines)
- Velocardiofacial syndrome with associated psychosis (a chromosomal disorder that results in poor development of several body functions)
What Are Side Effects of Tyrosine Hydroxylase Inhibitors?
Some of the side effects of THIs include:
- Sedation
- Diarrhea
- Fatigue
- Headache
- Nausea
- Vomiting
- Dysuria (painful urination)
- Movement disorders such as slowness of movements, irregular or jerky movements
- Sexual dysfunction
- Crystalluria (cloudy urine)
The information contained herein is not intended to cover all possible side effects, precautions, warnings, drug interactions, allergic reactions, or adverse effects. Check with your doctor or pharmacist to make sure these drugs do not cause any harm when you take them along with other medicines. Never stop taking your medication and never change your dose or frequency without consulting your doctor.
