Metoprolol Citalopram

METOPROLOL SSRIs T plasma concentrations of metoprolol SSRIs inhibit metabolism of metoprolol (paroxetine, fluoxetine, sertraline, fluvoxamine via CYP2D6, and (es)citalopram via mechanism uncertain at present) Monitor PR and BP at least weekly watch for metoprolol toxicity, in particular loss of its cardioselectivity... 

Metoprolol Escitalopram and citalopram may increase plasma levels of metoprolol. 

Ajmaline, alprenolol, amiflamine, amphetamine, aprindine, captopril, chlorpheniramine, cinnarizine, citalopram, clomipramine, clozapine, codeine, desipramine, dolasteron, encainide, flecainide, fluoxetine, fluphenazine, haloperidol, hydrocordone, imipramine, loratidine, methoxyphenamine, 3,4-methylenedioxymethamphetamine, metoprolol, mexiletine, (S)- and (i )-mianserin, nifedipine, olanzapine, omeprazole, oxycodone, perhexiline, phenformin, propaphenone, propranolol, remoxipride, ritonavir, saquinavir, selegiline, tamsulosin, timolol, tomoxetine, tramadol, trifluperidol, zolpidem... 

At 20 mg/day of escitalopram (twice the recommended daily starting dose), there is some elevation in levels of coadministered desipramine and metoprolol, which appear comparable to the effect of RS-citalopram.i i 2°... 

P-adrenergic blockers Citalopram may increase plasma levels of various P-blockers (mainly evident with metoprolol). 

Fluoxetine can increase serum pindolol and carvedilol levels, but the clinical effects of this are minimal. Isolated reports describe lethargy and bradycardia in patients taking metoprolol with fluoxetine and propranolol with fluoxetine or fluvoxamine. Flu-voxamine may increase the levels of propranolol, but not atenolol. Paroxetine may increase levels of metoprolol resulting in increased beta-blocking effects. Citalopram and escitalopram may interact similarly. Sertraline does not interact with atenolol. 

The UK manufacturers of citalopram say that no pharmacodynamic interactions have been noted in clinical studies in which citalopram was given with beta blockers. However the US manufacturers say that although the concurrent use of metoprolol and citalopram has no clinically significant effect on heart rate and blood pressure, the plasma levels of metoprolol are increased twofold, which may decrease its cardioselectivity. ... 

Fluoxetine and paroxetine inhibit the cytochrome P450 isoenzyme CYP2D6 thus inhibiting the metabolism of some beta blockers (e.g. propranolol, metoprolol, carvedilol) so that they accumulate, the result being that their effects, such as bradycardia, may be increased. Citalopram and escitalopram may also inhibit CYP2D6. In vitro studies with human liver microsomes found that fluoxetine and paroxetine are potent inhibitors of metoprolol metabolism and fluvoxamine, sertraline and citalopram less potent. However, fluvoxamine also potently inhibits the metabolism of propranolol by CYP1A2. Beta blockers that are not extensively me-... 

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