Aptripla and Celexa

[mike2002]

Does this mean the celexa is making the efavirenz less effective?

The following is from AIDSMEDS - Check interactions.

 Moderate Drug-Drug Interaction: Celexa (citalopram) and Atripla (efavirenz/emtricitabine/tenofovir)
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* The interaction is due to efavirenz which is a component of citalopram
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MONITOR: Coadministration with efavirenz may decrease the plasma concentrations of drugs that are substrates of the CYP450 3A4 isoenzyme. The mechanism is accelerated clearance due to induction of CYP450 3A4 activity by efavirenz. MANAGEMENT: Caution is advised if efavirenz must be used concomitantly with medications that undergo metabolism by CYP450 3A4, particularly those with a narrow therapeutic range. Dosage adjustments as well as clinical and laboratory monitoring may be appropriate for some drugs whenever efavirenz is added to or withdrawn from therapy.
 
Thanks
Mike

[Tempeboy]

Hi Mike,

You should ask your doctor or pharmacist, however, the most likely effect of taking Efavirenz with Citalopram would be an increased blood level of citalopram.  This would only be a problem if you were taking citalopram at maximum doses.

There would be no increased or decreased activity for Efavirenz.

In Australia Citalopram is manufactured in 20mg tabs and is prescribed from doses of 10mg (1/2 tab) to 60mg (3 tabs).  Citalopram is tolerated fairly well at much higher doses (we know this from accounts of overdose) so anyone taking these drugs together would only need to monitor the therapeutic effects and the side effects of Citalopram.

Also, citalopram is metabolised and excreted through multiple pathways, ie is broken up by other mechanisms in the body, so again the chances of problems is minimal.

http://depts.washington.edu/madclin/pharmacy/drugs/antidepressant.pdf

Hope this helps

J x