The combination of venlafaxine with MAOI preparations is prohibited.
There have been reports of serious side effects in people who stopped taking MAOIs shortly before starting venlafaxine or taking venlafaxine shortly before using MAOI. Among the reactions are convulsions, vomiting, tremor with nausea, as well as dizziness, profuse type sweating and fever, against which there were signs such as CNS and seizures, and sometimes death.
As a result, venlafaxine should be used at least 2 weeks after completion of therapy with MAOI.
It is recommended to observe a minimum of 14 days between the end of the use of circulating MAOI with moclobemide, as well as the initiation of venlafaxine therapy. When using MAOIs due to the adverse reactions described above, during this transfer of the patient to venlafaxine from moclobemide, this period should be at least 1 week.
Medicines that have an effect on the function of HC.
Taking into account the mechanism of medicinal action of Velaxin, and in addition to the risk of the appearance of serotonin intoxication, in the case of a combination of this drug with agents capable of influencing the transmission of nerve impulses of the serotonergic type (among them selective drugs-inhibitors of reverse serotonin capture, tripartine or lithium drugs), therapy is necessary to conduct with care.
Taking the medication together with indinavir caused a decrease in the peak level and AUC values of the latter by 36% and 28%, respectively. In addition, indinavir had no effect on the pharmacokinetic characteristics of venlafaxine with EFA.
In persons taking warfarin, with the onset of venlafaxine use, an increase in anticoagulant properties may be observed. In addition, there is an increase in the indices of PTV.
Since haloperidol is able to accumulate in the body, its effect can be enhanced.
Cimetidine in equilibrium values is able to inhibit the process of metabolism of venlafaxine on the first pass, but it does not have a significant effect on the formation and elimination of B-desmethyl-venlafaxine, located in the circulatory system in much more significant quantities. This allows us to conclude that a combination of the above medicines in a healthy person will not require a change in dosage. But in elderly people with a disorder in the liver, such a combination should be used cautiously, because there is no information on the interaction of drugs. In such a case, constant monitoring of the therapy process is required.
Medications that slow down the effect of the element CYP2D6.
Isoenzyme CYP2D6, which is responsible for the processes of genetic polymorphism, and affects the metabolism of a large number of antidepressants, converts venlafaxine substance into its main decay product - ODV. This creates the conditions for the development of the interaction of Velaxin with the inhibitory drugs of the element CYP2D6.
Interactions that reduce the amount of the active component transformed into ODV, in theory, can increase the values of the substance within the serum and decrease the indices of its active degradation product.
Ketoconazole (an inhibitory substance of element CYP3A4).
Tests of ketoconazole in fast as well as slow metabolizers of the CYP2D6 component showed that when using this drug, the venlafaxine AUC value rises (respectively, by 21% and 70%). The level of O-desmethylvenlafaxine is also increasing (by 23% and 33%, respectively).
Combination of drugs with inhibitors of CYP3A4 substance (among them itraconazole, clarithromycin with atazanavir and voriconazole, and in addition indinavir, saquinavir and posakonazol with nelfinavir and telithromycin, and ketoconazole with ritonavir) increases the performance of the active drug component and EFA. Because of this, it is required to combine with the above described drugs and Velaxin with caution.
Hypoglycemic and hypotensive drugs.
There is an increase in the indices of clozapine, which has a temporary connection with the development of side effects (this includes seizures), after the completion of venlafaxine use.
When taking venlafaxine, you must stop using alcohol.