Cetrotide (cetrorelix acetate for injection) is a synthetic decapeptide with gonadotropinreleasing
hormone (GnRH) antagonistic activity. Cetrotide (cetrorelix acetate for injection) is indicated for the inhibition of premature LH surges in women undergoing controlled ovarian stimulation.
Ovarian stimulation therapy with gonadotropins (FSH, HMG) is started on cycle Day 2 or 3.
The dose of gonadotropins should be adjusted according to individual response. CetrotideTM
(cetrorelix acetate for injection) may be administered subcutaneously either once daily
(0.25 mg dose) or once (3 mg dose) during the early- to mid-follicular phase.
In the single dose regimen, 3 mg of Cetrotideä is administered when the serum estradiol
level is indicative of an appropriate stimulation response, usually on stimulation day 7 (range
day 5-9). If hCG has not been administered within four days after injection of Cetrotide
3 mg, CetrotideT0.25 mg should be administered once daily until the day of hCG
administration.
In the multiple dose regimen, 0.25 mg of Cetrotideä is administered on either stimulation
day 5 (morning or evening) or day 6 (morning) and continued daily until the day of hCG
administration.
When assessment by ultrasound shows a sufficient number of follicles of adequate size, hCG
is administered to induce ovulation and final maturation of the oocytes. No hCG should be
administered if the ovaries show an excessive response to the treatment with gonadotropins
to reduce the chance of developing ovarian hyperstimulation syndrome (OHSS).
Administration
CetrotideT 0.25 mg and 3 mg can be administered by the patient herself after appropriate
instructions by her doctor.
Directions for using CetrotideT 0.25 mg and 3 mg:
1. Wash hands thoroughly with soap and water.
2. Flip off the plastic cover of the vial and wipe the aluminum ring and the rubber stopper
with an alcohol swab.
3. Put the injection needle with the yellow mark (20 gauge) on the pre-filled syringe.
4. Push the needle through the rubber stopper of the vial and slowly inject the solvent into
the vial.
5. Leaving the syringe on the vial, gently agitate the vial until the solution is clear and
without residues. Avoid forming bubbles.
6. Draw the total contents of the vial into the syringe. If necessary, invert the vial and
pull back the needle as far as needed to withdraw the entire contents of the vial.
7. Replace the needle with the yellow mark by the injection needle with the grey mark (27
gauge).
8. Invert the syringe and push the plunger until all air bubbles have been expelled.
9. Choose an injection site at the lower abdominal wall, preferably around the navel. If
you are on a multiple dose (0.25 mg) regimen, choose a different injection site each day
to minimize local irritation. Use the second alcohol swab to clean the skin at the
injection site. Gently pinch up the skin surrounding the site of injection.
10. Insert the needle completely into the skin at an angle of about 45 degrees.
11. Once you have inserted the needle completely, release your grasp of the skin.
12. Gently pull back the plunger of the syringe to check the correct positioning of the needle.
· If no blood appears, inject the entire solution by slowly pushing the plunger.
Thereafter, withdraw the needle and gently press the alcohol swab on the injection
site.
· If blood appears, withdraw the needle with the syringe and gently press the alcohol
swab on the injection site. Discard the syringe and the drug vial. Use a new pack
and repeat the procedure.
13. Use the syringe and needles only once. Dispose of the syringe and needles properly
after use. If available, use a medical waste container for disposal.
GnRH induces the production and release of luteinizing hormone (LH) and follicle
stimulating hormone (FSH) from the gonadotrophic cells of the anterior pituitary. Due to a
positive estradiol (E2) feedback at midcycle, GnRH liberation is enhanced resulting in an LHsurge.
This LH-surge induces the ovulation of the dominant follicle, resumption of oocyte
meiosis and subsequently luteinization as indicated by rising progesterone levels.
Cetrotide competes with natural GnRH for binding to membrane receptors on pituitary cells
and thus controls the release of LH and FSH in a dose-dependent manner. The onset of LH
suppression is approximately one hour with the 3 mg dose and two hours with the 0.25 mg
dose. This suppression is maintained by continuous treatment and there is a more
pronounced effect on LH than on FSH. An initial release of endogenous gonadotropins has
not been detected with Cetrotide, which is consistent with an antagonist effect. The effects of Cetrotide™ on LH and FSH are reversible after discontinuation of treatment.
In women, Cetrotide delays the LH-surge, and consequently ovulation, in a dose-dependent
fashion. FSH levels are not affected at the doses used during controlled ovarian stimulation.
Following a single 3 mg dose of Cetrotide, duration of action of at least 4 days has been
established. A dose of Cetrotide 0.25 mg every 24 hours has been shown to maintain the
effect.