Венлафаксин

White Solid

A optically active version of Venlafaxine, a selective serotonin noradrenaline reuptake inhibitor. Used as an antidepressant

ChEBI: A tertiary amino compound that is N,N-dimethylethanamine substituted at position 1 by a 1-hydroxycyclohexyl and 4-methoxyphenyl group.

Venlafaxine (Effexor) inhibits the reuptake of both serotonin and norepinephrine at their respective presynaptic sites.This drug does not have significant effects at muscarinic, histamine, or α-adrenergic receptors and therefore is devoid of many of the side effects associated with the TCAs.Venlafaxine and its active metabolite O-desmethyl-venlafaxine, have half lives of 5 and 11 hours respectively, so dosing twice a day is necessary. However, an extended release preparation (Effexor XR) now allows for once-daily dosing and better tolerance. Venlafaxine has a side effect profile similar to that of the SSRIs. Higher doses of venlafaxine result in modest increases in blood pressure in approximately 5% of patients.Venlafaxine has minimal effects on the cytochrome P450 enzyme system.

The structure and activity of venlafaxine (Effexor) are in accordwith the general SARs for the group. As expected, it isan effective antidepressant. Venlafaxine is a serotonin–norepinephrinereuptake inhibitor (SNRI).

Venlafaxine is a serotonin and noradrenalin reuptake inhibitor (SNRI) and is used as an antidepressant. Compared to tricyclic antidepressants, it lacks the antimuscarinic and sedative side effects. Nevertheless, treatment with venlafaxine can lead to a higher risk of withdrawal symptoms.

Venlafaxine is a methoxyphenylethylamine antidepressant that resembles an open TCA with one of the aromatic rings replaced by a cyclohexanol ring and a dimethylaminomethyl group rather than a dimethylaminopropyl chain.

The potential for cardiotoxicity with venlafaxine during normal use and for various toxicities in overdose situations are key concerns. Venlafaxine displays minimal in vitro affinity for the other neural neurotransmitter receptors and, thus, a low probability for adverse effects. To minimize GI upset (e.g., nausea), venlafaxine can be taken with food without affecting its GI absorption. Venlafaxine should be administered as a single daily dose with food at approximately the same time each day. The extended-release capsules should be swallowed whole with fluid and should not be divided, crushed, chewed, or placed in water.
Whenever venlafaxine is being discontinued after more than 1 week of therapy, it generally is recommended that the patient be closely monitored and the dosage of the drug be tapered gradually to reduce the risk of withdrawal symptoms.
Although venlafaxine is a weak inhibitor of CYP2D6, variability has been observed in the pharmacokinetic parameters of venlafaxine in patients with hepatic or renal function impairment. As a precaution, elderly patients taking venlafaxine concurrently with a drug that has a narrow therapeutic index and also is metabolized by CYP2D6 should be carefully monitored. Concurrent use of CYP3A4 inhibitors with venlafaxine has been shown to interfere with its metabolism and clearance. Similar to the other antidepressants that block 5-HT reuptake, venlafaxine may interact pharmacodynamically to cause toxic levels of 5-HT to accumulate, leading to the 5-HT syndrome.