Venlafaxine

introduction

Venlafaxine is classified as an antidepressant that is one of the selective serotonin-norepinephrine reuptake inhibitors (SSNRIs). By increasing the serotonin and norepinephrine levels in the central nervous system, the drug increases drive and reduces anxiety. For this reason, it is used to treat anxiety disorders and severe depression.

Children and adolescents are known to have a significantly increased risk of side effects such as suicidal thoughts and hostility, which is why venlafaxine is not approved for treatment under 18 years of age.

indication

Venlafaxine has an antidepressant effect by increasing various transmitter concentrations in the brain. It is prescribed for the treatment of severe depression, although it should be noted that the desired effect will only be achieved with continued use.

As already mentioned, venlafaxine can also be used to treat anxiety disorders such as panic attacks. Agoraphobia, also known as claustrophobia, when you feel very unwell in front of certain places and crowds, is one of these disorders. Another example are social phobias, in which there is a fear of contact with (mainly) strangers.

Venlafaxine can also improve symptoms in generalized anxiety disorders. Almost all areas of the patient's life are affected, which means that they are exposed to constant stress. This results in symptoms such as easy irritability, difficulty concentrating, restlessness and easy fatigue.

You might also be interested in: Homeopathy for panic attacks

Effect and active ingredient

The transmitters serontonin and norepinephrine in the central nervous system play an important role in both depression and anxiety disorders. The exact cause has not yet been clarified, but with these clinical pictures there is a deficiency in the two substances. Vanlafaxine works by increasing the serotonin level between the nerve cells, more precisely at the synapses. This is done by blocking the serotonin transporter for resumption of the transmitter, which leaves it in the gap.

Read more on this topic: The role of serotonin and norepinephrine in depression

When excitation is transmitted between two nerve cells, the transmitter is released from the first nerve cell into the synaptic gap in order to get to the second nerve cell and forward the signal there via receptors. After that, serotonin would normally be taken up again in the first cell. If, as with venlafaxine, the amount of transmitters is increased, the signal is amplified and lengthened.

Side effects of venlafaxine

Antidepressants like venlafaxine are known to have a wide range of side effects. These occur more frequently at the beginning of the treatment. Most of the time, however, the side effects disappear after prolonged use of the preparation. However, the group of selective serotonin reuptake inhibitors (SSRIs) is better tolerated than the tricyclic antidepressants that were used more often in the past.

Very often (more than 1 in 10 patients) headache and nausea occur during treatment. Patients also very commonly report being very dizzy, having a dry mouth, and sweating excessively (including night sweats). In addition, there are often weight changes due to a change in appetite. Depending on the patient, both weight gain and weight loss are possible.

Another common side effect of treatment with venlafaxine is loss of libido (sexual desire). Irregular menstruation in women and ejaculation disorders in men are possible.

Finally, there are often side effects in the gastrointestinal tract, with patients complaining of diarrhea and constipation. Further side effects can be found in the package insert.

Interactions

Venlafaxine is taken as a tablet and activated in the liver by specific enzymes. Numerous interactions with other drugs can occur, which are also metabolized by the same enzyme.

In addition, venlafaxine should not be combined with MAO inhibitors (including selegiline, tranylcypromine). Due to a mutually reinforcing effect, there is a risk of massively increased serotonin levels in the central nervous system, which causes the serotonin syndrome (symptoms: palpitations, seizures, impaired consciousness, nausea, and much more). Therefore, the simultaneous use of venlafaxine with other drugs that increase serotonin levels (serotonergic drugs, such as other antidepressants) should be avoided as far as possible.

dosage

For depression, the usual starting dose is 75 mg a day. This dose can be increased continuously to a maximum of 375 mg during the course of therapy if the effect is absent or weak. The attending physician should always increase the dosage. Abrupt discontinuation of drug therapy should be avoided, as this can lead to typical withdrawal symptoms (dizziness, sleep disorders, nausea, vomiting, tremors, and many more).

The treatment of generalized and social anxiety disorders is the same as for the treatment of depression. However, the maximum dosage is 225 mg per day. For panic disorders you start with a lower dose (37.5 mg per day) before you can slowly increase it to 225 mg.

Metabolism in the liver and excretion via the kidneys can lead to significant changes in the levels of active substances in the blood in liver and kidney dysfunction. For this reason, the dose in these patients should be adjusted by the attending physician.

price

Venlafaxine requires a prescription and is sold in pharmacies in different doses (37.5 mg and 75 mg). Different pack sizes (20, 50, 100 tablets per pack) are also available.

A 20-pack with the smaller dose of 37.5 mg venlafaxine per tablet costs around 15 euros. Instead, you can buy the larger 50-pack from around 20 euros. The price for the pack of 100 is around 30 euros.