Is there an interaction between beta-receptor antagonists and mirtazapine?/nA 23-year-old woman is

Fråga: Is there an interaction between beta-receptor antagonists and mirtazapine?

A 23-year-old woman is treated with mirtazapin (Remeron) for depression. Treatment with a beta-blocker is considered as prophylaxis against stress-induced headache.

Sammanfattning: The potential of a pharmacokinetic interaction between mirtazapine and metoprolol and propanolol cannot be excluded due to metabolism by the same isoenzyme CYP2D6. However, the clinical outcome of such an interaction can not be predicted. Since atenolol is excreted unchanged and not metabolised, atenolol may be a better alternative during coadministration of mirtazapine in this case.

Svar: Mirtazapine is an antidepressant drug and works as a noradrenergic and serotonergic receptor antagonist (1). Enzymatic pathways for metabolism of mirtazapine include CYP2D6, CYP3A4 and CYP1A2 (2). Studies have also indicated that mirtazapine is a weak inhibitor of the isoenzymes CYP2D6 and CYP3A4 (3).

According to (4) the only beta-receptor antagonists with the indication migraine are the selective beta-1-receptor antagonist metoprolol (Seloken) and the non-selective propanolol (Inderal). The CYP2D6 enzyme is involved in the metabolism of metoprolol and propanolol (5). Another selective beta-1-receptor antagonist atenolol (Tenormin) is hydrophilic and not metabolised by CYP2D6 (5). All three beta-receptor antagonists are effective as long-term prophylactic treatment of migraine, although propanolol has been most extensively studied (6). It should also be pointed out that beta-receptor antagonists may induce depression with the risk of an aggravation of the depression. However, this is a rare side-effect (4). 1 Richelsen E: Pharmacokinetic drug interactions of new antidepressants: a review of the effects on the metabolism of other drugs. Mayo Clin Proc 1997; 72: 835-847

2 Drugline nr 14632 (year 1998)
3 Drugline nr 14379 (year 1997)
4 FASS 1997 (The Swedish catalogue of approved medical products)
5 Drugline nr 13870 (year 1996)

6 Massiou H, Bousser MG: Beta-blockers and migraine. Pathol Biol 1992; 40: 373-380