Misc Chlorpheniramine & Serotonergic Opioids

[supersonic89]

Hi guys.

I have a little doubt and I need some help.

According to Wikipedia:

In addition to acting as an inverse agonist at the H1 receptor, chlorphenamine has been found to act as a serotonin reuptake inhibitor (Kd = 15.2 nM for the serotonin transporter).

Chlorphenamine - Wikipedia

en.wikipedia.org

So according to what I read, is it better to avoid chlorpheniramine if I want to use an opioid that has important effects on serotonin (Tramadol or Meperidine)? To avoid a serotonin syndrome, right?

I also wonder that since chlorpheniramine has a serotonergic action similar to SSRIs, does it inhibit the enzymes needed to metabolize pro-drug opioids such as Hydrocodone, Tramadol or Codeine?

 

[DeathIndustrial88]

This is a good question and I wish I had the answer. I'm surprised no one's answered this.

I would assume it might not be the best to mix with serotonergic opioids. Benadryl supposedly affects serotonin slightly too, but I have mixed benadryl and tramadol before with no problems. But in the case with benadryl, you want to take it long after the tramadol has been metabolized otherwise it can inhibit it's metabolism into O-desmethyltramadol.

High dose chlorpheniramine is more likely to cause seizures than say benadryl I think.
There are also Chlorphen/Hydrocodone combination preparations too I believe.

 

[supersonic89]

This is a good question and I wish I had the answer. I'm surprised no one's answered this.

I would assume it might not be the best to mix with serotonergic opioids. Benadryl supposedly affects serotonin slightly too, but I have mixed benadryl and tramadol before with no problems. But in the case with benadryl, you want to take it long after the tramadol has been metabolized otherwise it can inhibit it's metabolism into O-desmethyltramadol.

High dose chlorpheniramine is more likely to cause seizures than say benadryl I think.
There are also Chlorphen/Hydrocodone combination preparations too I believe.

Yes, better not to mix them or at least not in very large doses. Some day I took chlorphenamine and 15-20 hours later when I took tramadol (400 mg.) I started vomiting violently (it had never happened to me).
I believe that the serotorgenic action of chlorphenamine should not be underestimated. In fact, every time I take it I notice a certain anxiolytic and anti-depressant effect (more noticeable the day after taking it).