# Trigger drugs : specific role



## Guest (May 1, 2009)

Hi 

Do the tigger drugs (Pregnyl etc) initiate the LH-surge process ie towards ovualtion, or do they just mature the eggs and the rest just happens naturally IYSWIM? It seems from reading it is the former when I thought it was the latter?     

Thnx

xxx


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## mazv (Jul 31, 2006)

Hi Lukey,

Pregnyl does both    Basically hCG is almost chemically identical to LH and does the same thing (acts via the LH receptors in exactly the same way that LH does). In IVF/ICSI when you've been using down reg drugs then you won't have a natural LH surge so the hCG mimicks this and causes final maturation of the follicle ready to release the egg, although in this case the timing means they are collected artificially when you have EC. When used during OI protocols they do what LH does and mature the eggs and follicle and then this will naturally rupture and release the egg/s.

Hope this helps?

Maz x


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## Guest (May 27, 2009)

Mazv - thnx - and does Ovitrelle work in exactly the same way? ie maturing the eggs _and _ causing ovulation (I know it is in a prefilled jab so a bit different to administer etc). How, if at all ,is OVitrelle different to Pregnyl?

Similarly - I understand Ovitrelle is 7500units and Pregnyl is usually 2 x 5000s (ie 10000!) - are they equivalent in "activity" at these doses? ie is the 7500 of Ovitrelle equal in effect to the 10000 of Pregnyl? or is 10,000 of Pregnyl slightly more "aggressive"? (IYSWIM!)

Thnx!

xxx


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## mazv (Jul 31, 2006)

Ovitrelle does exactly the same as Pregnyl. Ovitrelle is genetically engineered chorionic gonadotrophin from chinese hamster ovaries (it is chemically identical to hCG, has the same amino acid sequence). Pregnyl is human chorionic gonadotrophin extracted from the urine of pregnant women (the natural hormone). They are exactly the same just obtained from different sources.

Ovitrelle is defined in micrograms/ml as opposed to units of activity but it equates to roughly 6500IU of hCG. Clinical trials have shown it to be equally effective to doses of up to 10,000IU of urinary hCG when used in ART. So basically it is exactly the same as Pregnyl in terms of its chemical structure, mode of action and effect in the body.

Why clinics use one product over another is anyone's guess   If you are asking my opinion then there is absolutely no difference between them.

Hope this helps
Maz x


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## Guest (May 28, 2009)

Mazv you are fab  - so to clarify - 6500 of Ovitrelle (ie one normal jab) would do exactly the same thing as "up to 10,000" of Pregnyl? - the Pregnyl would not do more? ie induce ovuation earlier or something.....     

xxx


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## mazv (Jul 31, 2006)

Yep do exactly the same thing, absolutely no clinical difference between them. The doses are just a fixed amount of drug that will guarentee the same physiological response when injected into the body. Everyone is different though so ovulation won't occur at exactly the same minute in all women and like wise it may vary between cycles in the same woman.

Maz x


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## Guest (May 30, 2009)

Thanks Mazv


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## Guest (Jun 2, 2009)

Oh ..... one more for you Mazv! 

So if pregnyl 10,000 is roughyl the same as Ovitrelle (6500) - can you tell me what pregnyl 15,000 will do over and above the 10,000? ie does it mature the eggs more or does it make you ovulate earlier? Just tryng to understand what the additional 5000 dose would actually do inside you etc?

Thnx!

xxx


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## mazv (Jul 31, 2006)

Nothing as far as I can tell. The minimum effective dose to mature follicle and stimulate ovulation is 5000 units. The licensed dose for use in IVF is 5000 - 10000 units. This dose should be adequate to cause a clinical response in most patients via stimulation of the bodies LH receptors. The only reason to give 15,000 that I can think of is that individuals may be less responsive to lower doses (need higher doses to fully activate the clinical response via LH receptors) Can't see how it would make you ovulate at a different time  

Maz x


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## Guest (Jun 3, 2009)

so as far as you can tell Mazv, you don't think 15,000 would mature the eggs more or make you ovulate earlier? 

xxx


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## mazv (Jul 31, 2006)

Nope


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## Guest (Jun 3, 2009)

cool  - so what is the point of it then    - they must think it MAY help with maturation or they would not do it right? and a good few top places do.....


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