arimidix vs aromasin

[QuadPower]

Both are AIs from what I understand, but:

arimidix aka anastrozole binds reversibly to aromatase
aromasin aka exemestane is a suicide inhibitor and binds irreversibly to aromatase

Assuming for now that cost is not a factor, why should I choose arimidix during cycle and aromasin after cycle during PCT?

Isnt there a risk of rebound with arimidix, since the binding to aromatase is reversible? Would I be better off using aromasin on and after cycle?

Also, what happens to the bound aromatase? How does your body eliminate it?

[WOLFCRAFT]

I think most people will tell you that letro during cycle is a better choice.
The aromasin in your PCT will take care of any rebound effect from it.

[RapaciousShark]

aromasin shouldn't be used for more than 4 weeks imo. It takes a long time to recover from it. People think letro is stronger but in the long run aromasin beats them all because it cripples your estrogen production for ages. You can just abruptly stop taking a full dose after 3 weeks and it would be the same as if you were still taking it. I've done it.

I wouldn't use it for any amount of time on cycle bc it leaves you wondering how to structure your PCT. It is great for killing rebounds as thunder says.

[RapaciousShark]

presumably the bound aromatase would just get metabolized like all other cell waste instead of entering the cell nucleus and initiating transcription. Aromatase production continues as usual, so the effects aren't permanent.

[QuadPower]

I think most people will tell you that letro during cycle is a better choice.
The aromasin in your PCT will take care of any rebound effect from it.

Relly? Why is letro a better choice on cycle than arimidix? Just wondering coz I need to order my PCT meds soon.

[DS21]

What is your cycle going to be? If it is test only I would run a low dose of arimidex on cycle and use aromasin pct with nolva.

[jc95605]

If you take letro during cycle you could use adex during pct to control the rebound effects?

[QuadPower]

What is your cycle going to be? If it is test only I would run a low dose of arimidex on cycle and use aromasin pct with nolva.

It is going to be a test e cycle... first one... 500 mg/wk broken down into 2 250 mg shots.

If letro is preferable I don't mind getting that, I'd like to know why one is preferred over the other though. Just confused right now because I'm trying to decide on all the meds for my PCT and went through a bunch of stickies and they are all ever so slightly different, in compounds, dosages and length.

[Mulciber]

aromasin is an irreversible, steroidal aromatase inactivator.. it prevents any conversion of test to estrogen. increased test levels due to this is also a benefit.

here is some more info showing that it has a positive effect on lipids and a neutral effect on cholesterol as well

Ann Oncol. 2004 Feb;15(2):211-7. Related Articles, Links


The effect of exemestane on serum lipid profile in postmenopausal women with metastatic breast cancer: a companion study to EORTC Trial 10951, 'Randomized phase II study in first line hormonal treatment for metastatic breast cancer with exemestane or tamoxifen in postmenopausal patients'.

Atalay G, Dirix L, Biganzoli L, Beex L, Nooij M, Cameron D, Lohrisch C, Cufer T, Lobelle JP, Mattiaci MR, Piccart M, Paridaens R.

Jules Bordet Institute, Brussels.

BACKGROUND: The impact of aromatase inhibitors (AIs) on non-cancer-related outcomes, which are known to be affected by oestrogens, has become increasingly important in postmenopausal women with hormone-dependent breast cancer. So far, data related to the effect of AIs on lipid profile in postmenopausal women is scarce. This study, as a companion substudy of an EORTC phase II trial (10951), evaluated the impact of exemestane, a steroidal aromatase inactivator, on the lipid profile of postmenopausal metastatic breast cancer (MBC) patients. PATIENTS AND METHODS: The EORTC trial 10951 randomised 122 postmenopausal breast cancer patients to exemestane (E) 25 mg (n = 62) or tamoxifen (T) 20 mg (n = 60) once daily as a first-line treatment in the metastatic setting. Exemestane showed promising results in all the primary efficacy end points of the trial (response rate, clinical benefit rate and response duration), and it was well tolerated with low incidence of serious toxicity. As a secondary end point of this phase II trial, serum triglycerides (TRG), high-density lipoprotein cholesterol (HDL), total cholesterol (TC), lipoprotein a (Lip a), and apolipoproteins (Apo) B and A1 were measured at baseline and while on therapy (at 8, 24 and 48 weeks) to assess the impact of exemestane and tamoxifen on serum lipid profiles. Of the 122 randomised patients, those who had baseline and at least one other lipid assessment are included in the present analysis. The patients who received concomitant drugs that could affect lipid profile are included only if these drugs were administered throughout the study treatment. Increase or decrease in lipid parameters within 20% of baseline were considered as non-significant and thus unchanged. RESULTS: Seventy-two patients (36 in both arms) were included in the statistical analysis. The majority of patients had abnormal TC and normal TRG, HDL, Apo A1, Apo B and Lip a levels at baseline. Neither exemestane nor tamoxifen had adverse effects on TC, HDL, Apo A1, Apo B or Lip a levels at 8, 24 and 48 weeks of treatment. Exemestane and tamoxifen had opposite effects on TRG levels: exemestane lowered while tamoxifen increased TRG levels over time. There were too few patients with normal baseline TC and abnormal TRG, HDL, Apo A1, Apo B and Lip a levels to allow for assessment of E's impact on these subsets. The atherogenic risk determined by Apo A1:Apo B and TC:HDL ratios remained unchanged throughout the treatment period in both the E and T arms. CONCLUSIONS: Overall, exemestane has no detrimental effect on cholesterol levels and the atherogenic indices, which are well-known risk factors for coronary artery disease. In addition, it has a beneficial effect on TRG levels. These data, coupled with E's excellent efficacy and tolerability, support further exploration of its potential in the metastatic, adjuvant and chemopreventive setting.

[WOLFCRAFT]

Relly? Why is letro a better choice on cycle than arimidix? Just wondering coz I need to order my PCT meds soon.

Best answer I can give...

Letro is more effective than armidex, and only a small dose (.25mg) is needed on cycle.

Also I've read that armidex and nolva are bad together because they sort of counter each other's effects. So if you were running armidex during cycle and nolva during PCT it might not be a good idea.

Someone else I'm sure can answer this better than I can.
But everything I've read favors letro over anything else for an on-cycle AI.

[jc95605]

Letro is more effective than armidex, and only a small dose (.25mg) is needed on cycle.

Also I've read that armidex and nolva are bad together because they sort of counter each other's effects. So if you were running armidex during cycle and nolva during PCT it might not be a good idea.

Someone else I'm sure can answer this better than I can.
But everything I've read favors letro over anything else for an on-cycle AI.[/QUOTE]

Yes but do we need anything to counter letro during pct if we take letro while on cycle?

[WOLFCRAFT]

Yes but do we need anything to counter letro during pct if we take letro while on cycle?

Yes, this is when it'd be a good idea to take aromasin or proviron.
It will stop any of the letro's estrogen rebounds.

[jc95605]

would adex do? I have an overstock of it so might as well use it.

[Mulciber]

it will do fine

[jc95605]

perfect then thats what i'll do. thanks guys.

[QuadPower]

would adex do? I have an overstock of it so might as well use it.

adex = arimidix?

If so then how would adex work to prevent letro rebound? Both arimidix and letro are reversible AIs, which is why you rebound on them in the first place. Aromasin used during PCT makes sense, since it will counter any estro rebound from arimidix or letro, by binding permanently to aromatase.

If you use arimidix to counter letro rebound, then what will counter the arimidix rebound that follows?

[jc95605]

ya thats what i was thinking. I was hoping i was wrong so i wouldn't have to buy something else. Damnit! Oh well, the best cycles are always the expensive ones.

[Mulciber]

letro should be tapered off due to estrogen rebound.. adex not so much imo