What are the side effects of Parnate


Trade name: Parnate®, Jatrosome® i.a.

1 definition

Tranylcypromine is an unselective and irreversible monoamine oxidase inhibitor used as a reserve drug to treat depression.

2 chemistry

Tranylcypromine is structurally related to amphetamine, but contains a cyclopropane ring. It also has two stereocenters, resulting in four possible stereoisomers. Only that is used as an active ingredient transPair of enantiomers.

Tranylcypromine has the molecular formula C.9H11N and a molar mass of 133.19 g / mol.

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3 Mechanism of Action

Depression is primarily characterized by a lack of drive and a disturbed mood. It is assumed that there is a primary deficiency of monoamines such as noradrenaline or serotonin in the synaptic gap, which is mainly due to a reduced production of the neurotransmitters mentioned. The changed expressivity, their receptors or the binding to them can also be a reason for the mentioned deficiency symptom and the associated symptoms. The therapeutic goal of antidepressants is therefore to increase the amount of monoamines in the synaptic gap through different points of attack.

A possible therapeutic approach to increase the monoamine concentration (especially serotonin and noradrenaline, but also adrenaline and dopamine) is the inhibition of monoamine oxidase-A (MAO-A). Their job is to break down monoamines.

Tranylcypromine is an unselective and irreversible MAO inhibitor. After activation by opening the cyclopropane ring, it binds covalently to FAD, the prosthetic group of the MAO, via a radical mechanism, whereby the enzyme is irreversibly inhibited ("suicide inhibition"). By inhibiting the MAO, the extracellular concentration of monoamines is increased, to which the antidepressant effect is attributed (see monoamine hypothesis).

4 indications

5 side effects

Since tranylcypromine not only inhibits MAO-A (breakdown of serotonin and noradrenaline), but also MAO-B (breakdown of dopamine), there are more side effects and drug interactions compared to selective MAO inhibitors (e.g. moclobemide).

Like amphetamines, Trancylpromin has an excitatory effect on the CNS; many of the side effects can be attributed to its stimulating effect:

The consumption of tyramine-containing foods such as red wine or cheese during therapy with tranylcypromine can lead to the so-called cheese effect: Tyramine ingested can no longer be broken down and enters the bloodstream. Tyramine itself acts as an indirect sympathomimetic by increasing the norepinephrine concentration in the synaptic cleft. Norepinephrine binds to alpha-1 receptors and leads to vasoconstriction and thus to an increase in blood pressure up to a hypertensive crisis. Accordingly, foods containing tyramine should be avoided during and at least 14 days after the last dose of tranylcypromine.

6 contraindications