Resources on Dosage Equivalencies?

[kty]

---

Members do not see this ad.

Hello,

I'm a PGY-2 who recently came across some old psychopharmacology articles by The Last Psychiatrist (ex. The Last Psychiatrist: Aren't Two Antipsychotics Better Than One? The Most Important Article on Psychiatry, Part 3), and was curious to know if there is any single resource that compares dosage equivalencies between antipsychotics, antidepressants, etc.

Any help would be greatly appreciated. Thank you.

 

[Old&InTheWay]

I am not aware of a single resource, but this is an interesting article that came out a few years back looking at typical effective doses of antipsychotics in schizophrenia.

Psychiatry Online

ajp.psychiatryonline.org

 

[kty]

I am not aware of a single resource, but this is an interesting article that came out a few years back looking at typical effective doses of antipsychotics in schizophrenia.

Psychiatry Online

ajp.psychiatryonline.org

Thank you very much.

 

[romanticscience]

I found this in my notes. PM for sources. Comments welcome!


Aripiprazole 2
Lurasidone 8
Quetiapine 50
Risperidone 0.6
Olanzapine 2
Haldol 1
Ziprasidone 16

Sertraline 60
Paroxetine 10
Fuoxetine 10
Citralopram 17
Escitalopram 8
Venlafaxine 88
Desvenlafaxine 35
Bupropion 138

Alprazolam 0.5
Lorazepam 1.0
Clonazepam 0.5
Diazepam 10
Temazepam 15
Zolpidem 20
Zaleplon 20
Eszopiclone 3.0

Ritalin 10mg
Focalin 5mg
Concerta 36mg
Adderall 5mg
Adderall XR 10mg
Dexedrine 3.75mg
Lisdexamph 12mg

 

[TexasPhysician]

I found this in my notes. PM for sources. Comments welcome!


Aripiprazole 2
Lurasidone 8
Quetiapine 50
Risperidone 0.6
Olanzapine 2
Haldol 1
Ziprasidone 16

Sertraline 60
Paroxetine 10
Fuoxetine 10
Citralopram 17
Escitalopram 8
Venlafaxine 88
Desvenlafaxine 35
Bupropion 138

Alprazolam 0.5
Lorazepam 1.0
Clonazepam 0.5
Diazepam 10
Temazepam 15
Zolpidem 20
Zaleplon 20
Eszopiclone 3.0

Ritalin 10mg
Focalin 5mg
Concerta 36mg
Adderall 5mg
Adderall XR 10mg
Dexedrine 3.75mg
Lisdexamph 12mg

I would have fairly different numbers. Few examples below:

Zyprexa - 10
Seroquel - 500
Geodon- 120

Vyvanse - 30
Adderall XR - 10

 

[calvnandhobbs68]

I would have fairly different numbers. Few examples below:

Zyprexa - 10
Seroquel - 500
Geodon- 120

Vyvanse - 30
Adderall XR - 10

Agree. I especially think seroquel is off. No way 50mg Seroquel = 1mg Haldol. 50mg Seroquel is basically a sleep aid. You aren't even getting to a real antipsychotic dose of Seroquel until 300-400mg wheras you're getting 50+% D2 blockade at about 1mg Haldol.

I also agree that your Vyvanse/Adderall XR conversion is more on par. I think I posted this on here somewhere before but most sources I've seen have stated 70mg Vyvanse= 30ish mg Adderall XR.

Abilify is also always difficult to directly compare anyway because of the partial agonist rather than antagonist effect.

 

[kty]

Much appreciated to all responses

 

[Evidence Based]

I am not aware of a single resource, but this is an interesting article that came out a few years back looking at typical effective doses of antipsychotics in schizophrenia.

Psychiatry Online

ajp.psychiatryonline.org

This is a great paper- the same authors just came out with a follow up on dose equivalencies for relapse prevention in stable patients with some slightly different numbers compared to the above paper which is in "acute" psychosis.

Dosing of Antipsychotic Drugs for Relapse Prevention in Schizophrenia

This meta-analysis examines dosing adjustments for prevention of relapse in patients with schizophrenia.

jamanetwork.com

 

[FlowRate]

I had mentioned in another thread recently that I had asked my CPS to look into resources on dose equivalents in terms of receptor binding. She sent that out to a listserv of other psych specialized CPS and basically the only things we found were the resources linked already in this thread.

 

[Old&InTheWay]

This is a great paper- the same authors just came out with a follow up on dose equivalencies for relapse prevention in stable patients with some slightly different numbers compared to the above paper which is in "acute" psychosis.

Dosing of Antipsychotic Drugs for Relapse Prevention in Schizophrenia

This meta-analysis examines dosing adjustments for prevention of relapse in patients with schizophrenia.

jamanetwork.com

One of the most interesting things about the study I cited is in table 1. It lists the ED50, ED95, expert consensus target doses, and FDA approval-based dosing. The expert consensus dosing aligns almost perfectly with Stahl's prescriber guide, which tells me that the "experts" are all getting their info from the same source (which incidentally is not backed up by data).

 

[clozareal]

The Maudsley prescribing guidelines book has equivalent doses for antipsychotics, minimum effective dose for antidepressants, and equivalent doses of benzodiazepines.

 

[Merovinge]

Ritalin 10mg
Focalin 5mg
Concerta 36mg
Adderall 5mg
Adderall XR 10mg
Dexedrine 3.75mg
Lisdexamph 12mg

Really important to recognize this is trying to give equivalents per peak of stimulant. In reality Ritalin 10mg TID = Concerta 36, Adderall 5mg BID = Adderall XR 10mg etc. As mentioned above, it's way off for Vyvanse which is chronically under dosed, Adderall XR 30mg = Vyvanse 70mg although the later will last longer.

 

[whopper]

The "dose equivalency" has to be based on some metric. E.g. % D2 blockage, % relapse, etc. No measure is perfect. Some meds are way better at D2 blockage vs another med yet have less efficacy. Clozapine vs Haldol for example. Clozapine works better for Schizophrenia despite that is has far weaker D2 blockage.

Also meds highly differ between patients and based on several factors we cannot discern until the patient takes the med. E.g. a patient could take one med, at whatever dose, and get no benefit form that med, but another med of the same class have a very good benefit at a low dosage. You have to enter "dose equivalency" in the understanding that with 2 different meds even of the same class there may be no equivalency whatsoever in the specific patient.

I have noticed dose equivalency does work better with benzos which all have the same mechanism but for meds such as antidepressants or antipsychotics there's a lot of room for one med to have nothing beneficial at all no matter what dosage was offered, to other meds working very well on the same patient. IT makes sense. The mechanisms between the antipsychotics differ and not just with D2 blockage. Similarly with antidepressants also highly vary with no dose equivalents being relevant unless the two meds are stereoisomers or prodrugs of the other. E.g. Citalopram vs Escitalopram or Venlafaxine vs Desvenlafaxine.