Uses of Lafaxor

Venlafaxine is a selective Serotonin and Norepinephrine reuptake inhibitor, which is indicated for use in the treatment of depression. Venlafaxine is the main ingredient in the drug product Lafaxor of Dat Vi Phu Joint Stock Company.

Venlafaxine component in the drug has the ability to inhibit the selective reuptake of Serotonin and Norepinephrine. Venlafaxin's antidepressant and antianxiety mechanisms are not well defined, however it is associated with its ability to enhance central nervous system neurotransmitter activity. Venlafaxine and its active metabolite, O-desmethyl-venlafaxine (ODV) are potent inhibitors of neuronal Serotonin and Norepinephrine reuptake and weaker Dopamine reuptake inhibitors.
In vitro studies have shown that venlafaxine and ODV have no appreciable affinity for Cholinergic, Muscarinic, H1 histaminergic or α-adrenergic receptors.

Lafaxor is indicated primarily for the treatment of depression, including depression with anxiety, in both inpatients and outpatients.
Lafaxor is contraindicated in the following cases:
Hypersensitivity to Venlafaxine or any of its ingredients; In combination with a monoamine oxidase (MAO) inhibitor; Patients with high cardiovascular risk, including ventricular arrhythmias, uncontrolled hypertension...; Children under 18.

When using Lafaxor, patients may experience some unwanted effects. The most common are symptoms of nervous system disorders such as dizziness, dry mouth, insomnia, nervous mood or drowsiness. In addition, patients may experience digestive disorders (including anorexia, constipation, nausea), ejaculation/pleasure disorders, excessive sweating and weakness...
Frequency of side effects Undesirable effects of Lafaxor are dose related and generally improve in both magnitude and frequency with long-term use.

Concomitant use of Lafaxor with MAO inhibitors is contraindicated. The risk of co-administration of Lafaxor with other CNS-acting agents has not been systematically evaluated. Therefore, care should be taken when administering Lafaxor concomitantly with these drugs. The pharmacokinetics of Venlafaxine and O-desmethyl-venlafaxine were unchanged when co-administered with Diazepam or Lithium in healthy volunteers. Therefore, the use of Lafaxor did not affect the psychoactive effects of Diazepam. Cimetidine inhibits the first-pass metabolism of Venlafaxine but has no effect on O-desmethyl-venlafaxine formation or elimination. In general, the synergistic pharmacological effects of Venlafaxin and O-desmethyl-venlafaxin will only increase very slightly when co-administered with Cimetidine, so no dose adjustment is required. However, in elderly patients and patients with hepatic impairment, when Lafaxor is co-administered with Cimetidine, it is not clear how the interaction will occur, so these cases should be closely monitored. Symptoms observed in clinical studies in patients receiving Lafaxor concomitantly with antihypertensive or hypoglycemic agents have been reevaluated for drug interactions. To date, there is no evidence of an incompatibility between the use of Lafaxor and these two classes of drugs.

The risk of suicide in all depressed patients needs to be considered and taken into account, therefore Lafaxor should be prescribed only in small doses to provide good patient control and reduce the likelihood of overdose. Adverse reactions, sometimes serious, have been reported with the initiation of Lafaxor therapy shortly after discontinuation of an MAOI and conversely with the initiation of an MAOI shortly after discontinuation of Lafaxor. Reactions include: tremors, chorea, sweating, nausea, vomiting, hot flushes, dizziness, high fever with neuroleptic malignant syndrome-like features, convulsions and may cause dead. Drug interactions leading to these severe, sometimes fatal, reactions have been reported with concomitant or sequential administration of MAOIs and other antidepressants with pharmacological properties similar to Venlafaxine. Therefore, it is best not to take Lafaxor concomitantly with an MAOI or within 14 days after stopping treatment with an MAOI. Conversely, MAOIs should only be used after stopping Lafaxor for at least 7 days. Clinical studies have not reported any unusual symptoms with abrupt discontinuation of Lafaxor. However, patients who stop taking Lafaxor after 1 week of treatment with Lafaxor should still gradually reduce their dose to minimize the risk of withdrawal symptoms. Patients receiving Lafaxor for 6 weeks or more should be tapered gradually over 1 week. As with other antidepressants, patients taking Lafaxor should exercise caution when driving or operating complex machinery. There are no adequate and well-controlled studies with the use of Lafaxor in pregnant women. Therefore, Lafaxor should not be used in this patient unless the potential benefit to the mother outweighs the possible risks. Patients are advised to inform their doctor if they become pregnant or plan to become pregnant during treatment with Lafaxor. It is not known whether Venlafaxine and its metabolites are excreted in human milk. Therefore. Lafaxor should not be administered to a nursing patient.