Tomoxetine is a selective norepinephrine reuptake inhibitor (SNRI) with a structure similar to fluoxetine. This drug is the first excitatory drug approved for the treatment of attention deficit disorder with hyperactivity disorder (ADHD), and it has not been found in clinical trials to cause other excitatory drugs or typical reactions that can cause euphoria.
Mechanism of action
Currently, it is widely believed that the therapeutic effect of toroxetine hydrochloride is related to its selective inhibition of the reuptake effect of presynaptic amine pumps on NE.
Tomoxetine exerts a flipping effect by gradually increasing extracellular NE levels. In a mouse experiment, Tomoxetine showed a very high affinity for NE transporters, which prevented NE reuptake and increased neurotransmitters at the synapses of neurons in the prefrontal cortex of the rat brain.
Inhibition of NE reuptake → Enhancement of NE flipping effect → Improvement of ADHD symptoms → Indirect promotion of cognitive completion and concentration
Contraindications
Patients with angle closure glaucoma should not use this medication because the risk of developing mydriasis increases. In addition, this drug cannot be combined with monoamine oxidase inhibitors (MAOI); If MAOI must be given, it should be discontinued for at least two weeks before use. It is prohibited for those who are allergic to other components of the drug or inhibitor.
Precautions
The serum concentration of this drug in patients with weak metabolism of liver enzyme CYP2D6 may be higher than that of normal individuals. Therefore, it is necessary to reduce the dosage of medication. Clinical trials have found that the drug may slow down the normal development of height and weight in children. This drug may cause rare allergic reactions such as angioneurotic edema, rubella, and rash.
Adverse reactions
In clinical trials, the most common reasons for patients to withdraw midway include aggression, irritability, drowsiness, and vomiting. The most common adverse reactions include indigestion, nausea, vomiting, fatigue, decreased appetite, dizziness, and unstable mood. In addition to the adverse reactions exhibited by children and adolescent patients, adult patients can also experience dry mouth, erectile dysfunction, impotence, abnormal orgasm, etc.