Worried
about persistent thin Et , She is young ?? Thin ET ?? Tamoxifene.
Tamoxifen: -
The theoretical advantage of TMX over 1) CC is that it (TMX) does not exhibit
any antiestrogenic effect on cervical mucus or endometrium. As such, many
specialists use this drug (TMX) in cases
of CC failure (sometime in CC resistant too) - where there is a persistent
thin endometrium in previous CC cycles.
2) As an alternative
to Gonadotrophins as a treatment modality of thin ET:-Honestly
speaking, TMX, so far my belief goes, is occasionally used where couple can’t
afford for gonadotrophins.
Tamoxifen
is a SERM. Like Clomiphene this drug too was initially used for breast cancer. Tamoxifene has never been approved till date by any agency for
Ovulation induction. (Source: Hum. Reprod 2005; 29:1511).
It is claimed
that it (TMX) is as effective as CC in ovulation induction. It is initially used as 20 mg OD schedule. After two
failed cycles with TMX (if there is no evidence of ovulation) -the dose of
Tamoxifene can be increased in a stepwise fashion up to 60mg OD.
It is more probable that endogenous hormones become near normal in
pre-induction phase.
If ET is more than 5 mm,
better to induce withdrawal bleeding before ovulation induction.
The other alternative option is if on day 3 - ET is > 5 mm.
then one can possibly reschedule evaluation of ET after 48 hrs...In some cases,
however, on day 4 /5 ET may shrink down to expected 5 mm by waiting for 48 hrs.
Therefore, one can possibly gainfully utilize that cycle too by initiating
CC/tamoxifen/i.e. on day 5. ET may regress to 5 mm.
Tamoxifene: - The theoretical advantage of TMX over CC is that it (TMX) does not exhibit any antiestrogenic effect on cervical mucus or endometrium. As such, many specialists use this drug (TMX) in cases of CC failure (sometime in CC resistant too) - where there is a persistent thin endometrium in previous CC cycles.
Tamoxifene has never been approved till date by any agency for
Ovulation induction. (Source: Hum. Reprod 2005; 29:1511). It is claimed that it
(TMX) is as effective as CC in ovulation induction. It is initially used as 20
mg OD schedule. After two failed cycles with TMX (if there is no evidence of
ovulation) -the dose of Tamoxifene can be increased in a stepwise fashion up to
60mg OD.
Tamoxifen when?
Scope & Indications of Tamoxifen as Ovulogens:-:- In present day
the main and possibly the only indication of prescribing TMX is when there are
side effects with CC particularly visual /neurological side effects .
Scintillating...
Tamoxifen is the second choice in CC resistant cases. Better
option will be Gonadotrophins. Gonadotrophins are quite effective in CC
resistant cases but costly and requires rigorous monitoring. Such facilities
may not be available in rural settings. There remains a scope of TMX in selected cases
of CC failure/ resistance cases.
CC has failed after couple of cycles. Now, what are the practical
options open to young women in Indian perspective? Once counselling done after
several cycles of failed CC, many Indian couple (even uneducated couple) do
realize that gonadotrophin is badly needed for them but repent because they are
simply unable to afford for G cycle. Put in such a situation (after CC
resistant cases) the option remaining to the treating physician to prescribe
TMX (as an alternative to Gonadotrophin) and make some compromise. Doctor
feel-“Watch- what happens”-.
Ours is a resource poor country: Not to speak of cost of
purchasing Gonadotrophins: Many Indians even cannot afford common low cost
fertility tests (PRL,) that usually should precede CC therapy (tests for
medical fitness of pregnancy- IgG rubella, hepatitis Viral Screen, TSH, etc).
Not to speak of tests prior to initiation of Gonadotrophin—which is the
preferred agent most commonly used after CC failure/ Resistance. Not all such
tests are done free of cot in Govt/Municipal Hospitals.:--Unfortunately, many
Indian couple cannot afford for usual tests at this juncture - so as to why CC
failed in their case.
Such tests, if not carried
out earlier are 1) AMH .2) AFC, 3) Insulin Resistance, 4) high D2 LH &
testosterone 5) DHEASO4, & 6) PRL --not to speak of other costly tests. In
such cases further tests so as to find the etiology of CC resistant in
particular women. We, Indian doctors have to make many compromises at every
step of clinical practice not only in the discipline of reproductive medicine.
Like CC TMX is also an competitive estrogen Antagonist –TMX
,like CC also competitively block the
estrogen binding sites at the level of actuate nucleus of hypothalamus, and
stimulate GnRH receptors located at Pit for accentuated release of pit FSH
& LH.
Is there any differential expression of LH over FSH
–particularly in CC failure cases? In fact there
is about 3-4 fold rise of FSH & LH while someone is on CC.
But the differential
expression FSH & LH in the aforesaid two types of oral Ovulogens is still
under study. I have a feeling this part of CC /TMX have not been adequately
explored. It is hoped by many researcher that CC failure is due possibly to over expression of LH in fair number
women and is a major cause of CC failure poor oocyte quality.
Those who are biased for TMX they claim such disproportionate rise of LH on cycle days 8-11 is not the case with
YMX.
But many researcher believe that CC in fair no. of cases more
rise of LH during the cycle days of Day 8-Day 10thereby interfering the oocyte
quality. Similarly in some cases of CC induced cycle serum E2 remain at
supraphysiological levels –explain partly the reasons of failure of CC
cycles.
In such women one can use TMX
as an iterative if the age of the female partner is< 25 yrs or she cannot
afford for gonadotrophin cycle. Some also have claimed that LUF is more than
TMX.
Why oral Ovulogens
in lieu of gonadotrophins in CC resistant/Failure cases??- The
advantages of CC/ Tamoxifen are low incidence of multiple gestations, OHSS, low
cost, minimal monitoring, .But we are all aware of the fact that whatever agent
we use in fair number of subfertile women CC/TMX become resistant despite
appropriate dosage e.g. Ov insufficiency, Hyperandrogenism, Insulin resistance,
Elderly women and women with BMI> 30 Kg/M2. In such cases one prescribes
oral Ovulogens mostly CC but the doctor concerned is sceptical right from the
beginning that CC/TMX may not work.
Miscarriages rate and multiple pregnancy:--Such rates are more or
less same with CC and Tamoxifen :- e.g. 10% & ABOUT 22% RESPECTIVELY
DEPENDING ON OTHER ASSOCIATED FACTORES LIKE Age of female partner, BMI, ANDROGEN
EXCESS DISORDERS, Hyperinsulinemia, serum testosterone etc etc.
But for the oral Ovulogens to be effective the D2 serum E2 should be
ideally> 50 pg/ml and not less.
Additionally, Women why are contraindicated for CC may also be a given few cycles of TMX RY after due counselling. Such contraindications of CC are impairment of hepatic enzymes.
Tamoxifene:-
There are two important advantages of Tamoxifen over CC. These are
There are two important advantages of Tamoxifen over CC. These are
a) No
anti-estrogenic effects of CC on genital tract b) No recorded neurological abnormality as seen very occasionally in
CC cycles. Abnormalities of vision, the rare occurrence depression, grand mal
epilepsy and hallucinations are not heard of with TMX.
Additionally, researchers working with TMX and CC: - also claim that the very rare threat of Auditory nerve changes in CC induced cycles is nonexistent in TMX cycles.Moreover use of TMX in Ov induction is an “off-level use .
Additionally, researchers working with TMX and CC: - also claim that the very rare threat of Auditory nerve changes in CC induced cycles is nonexistent in TMX cycles.Moreover use of TMX in Ov induction is an “off-level use .
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