Dosing and uses of Antagon, Orgalutran (ganirelix)
Adult dosage forms and strengths
prefilled syringe
- 250mcg/0.5mL
Female Infertility
250 mcg SC qDay during mid-to-late follicular phase after initiating follicle-stimulating hormone on day 2 and 3 of the cycle, continue therapy until day of hCG administration
Pediatric dosage forms and strengths
Not recommended
Antagon, Orgalutran (ganirelix) adverse (side) effects
1-10%
Abdominal pain (1%)
Headache (3%)
Injection site recation (1%)
Nausea (1%)
Ovarian hyperstimulation syndrome (2%)
Vaginal bleeding (2%)
Pelvic pain (5%)
<1%
Anaphylactoid reactions
Warnings
Contraindications
Known or suspected pregnancy
Hypersensitivity to ganirelix, LHRH or LHRH analogs
Cautions
Exclude pregnancy before initiating therapy
Packaging may contain latex products, which may cause allergic reaction in susceptible patients
Use caution in women with sign and symptoms of active allergic conditions
Pregnancy and lactation
Pregnancy category: X
Lactation: Excretion unknown; not recommended
Pregnancy categories
A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.
B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.
C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done.
D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk.
X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist.
NA: Information not available.
Pharmacology of Antagon, Orgalutran (ganirelix)
Mechanism of action
Gonadotropin releasing-hormone antagonist; blocks endogenous LHRH in pituitary with high antagonistic activity & inhibits premature LH surges in patients undergoing controlled ovarian hyperstimulation; prevents ovulation until follicles are of adequate size
Pharmacokinetics
Half-Life: 12.8-16.2 hr (elimination)
Onset: Within 8 hr
Duration: <48 hr
Peak Plasma Time: ~1 hr
Bioavailability: 91%
Vd: 43.7 L (single dose); 76.5 L (multiple dosing)
Protein Bound: 82%
Metabolism: Liver
Total Body Clearance: 3-4 L/hr
Excretion: Feces (75%); urine (22%)
