ovulation-inducing agent presented by: zinab al-hajari
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Ovulation-Inducing
AgentPresented by: Zinab Al-hajari
Chemical structure:Clomiphene citrate is a
a non-steroidal selective estrogen receptor modulator (SERM) related structurally to triphenylethylene.
It is available as a racemic mixture of
cis (zuclomiphene) and trans form (enclomipene).
Cl
OCH2CH2NCH2CH3
CH2CH3
Mechanism of action:
Clomiphene is a partial agonist at oestrogen receptor.
It leads to an increase in the secretion of gonadotropins and oestrogen by inhibiting estradiol’s feedback effect on the gonadotropins.
Pituitary
hypothalamus
Ovaries
Estrogens
FSH + LH
Clomiphene Citrate
-Ve
+ Ve
+ Ve
Pharmacokinetics:Clomiphene is readily absorbed orally.Has a very large volume of distribution high bioavailability It reaches peak plasma concentration within 6h
Its half-life of an oral dose is about 5 days. Metabolized in the liver by the cytochrome P-450 pathway and there is evidence of enterohepatic recyclingExcreted principally in the feces and minimally
in the urine
Dosage:• The recommended dosage at the beginning of
therapy is 50 mg/d for 5 days, Starting on day 2–5 of the cycle .
ovulation
occurs Does not occur
The next course can be started (can be maintained for 6-12 m ) Double the dose to 100 mg/d
Patients who don’t ovulate for 3 courses
are unlikely to respond to
CC
Effects:Stimulate ovulation in women with
oligomenorrhea or amenorrhea due to ovulatory dysfunction.
The majority of patients suffer from polycystic ovary syndrome( 7% ), which is characterized by
Ovarian hyperandrogenism Olig- or anovulationInfertility
Ovulation can be documented by using any one of a number of methods: Basal body temperature (BBT)
Midcycle LH
Serial transvaginal ultrasound
Clinical uses:Used for treatment of disorders of ovulation in patients wishing to become pregnant.
It is not used in patient with pituitary or hypothalamic failure
Treatment of gynecomastia.
Treatment results:About 80% can be expected to respond by having ovulatory cycles.Approximately half of these patient become pregnantclomiphene resistant are likely to be
• obese• insuline resistant• hyperandrogenic
Adverse effects:Multiple pregnancy Ovarian enlargementAbdominal distension Hot flushesVisual symptomsNausea and VomitingHeadache
Serious medical conditions:
Ovarian hyperstimulation syndrome (OHSS):
Ovulation induction with injectable gonadotropins is a more common cause of OHSS than is clomiphene
serious medical complication characterized by: cystic enlargement of ovaries A marked increase in vascular permeability.
Overdose:As a result of the use of more than the recommended dose during clomiphene citrate therapy. Symptoms:
• Nausea, vomiting• Vasomotor flushes• visual blurring• Ovarian enlargement with pelvic or abdominal
pain.
Contraindication and cautions:
Pregnancy Nursing motherOvarian cyst or enlargement not due to PCOSLiver diseaseAny patient who complains of abdominal symptoms should be examined carefully Special precaution must be taken in patient who have visual symptomsOrganic intracranial lesion such as pituitary tumorHypersensitivity to the drug
Drug interaction:
Danazole may reduce the response to clomiphene
Alternative and combination regimen:
1- With insuline sensitizing agent2- With HCG3- With glucocorticoid
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