FERTINEX

Clinical safety rating: caution

Comprehensive clinical and safety monograph for FERTINEX (FERTINEX).

How it works

Follitropin beta, a recombinant form of human follicle-stimulating hormone (FSH), binds to the FSH receptor on ovarian granulosa cells and testicular Sertoli cells, stimulating follicular development and maturation in women and spermatogenesis in men.

What the body does with it

Metabolism	Metabolized primarily via the liver and kidneys; exact enzymes not fully characterized, but involves hepatic degradation and renal excretion.
Excretion	Primarily renal excretion of unchanged drug (80-90% of administered dose), with the remainder excreted as metabolites in urine and feces.
Half-life	Terminal elimination half-life is approximately 24-36 hours in patients with normal renal function, supporting once-daily dosing.
Protein binding	Approximately 60-70% bound to plasma proteins, primarily albumin.
Volume of Distribution	Vd is approximately 0.3-0.5 L/kg, indicating distribution mainly into extracellular fluid.
Bioavailability	Subcutaneous: ~70% relative to intravenous; intramuscular: ~90% relative to intravenous.
Onset of Action	Subcutaneous injection: Clinical effect (increase in serum estradiol) observed within 5-7 days of daily dosing; intramuscular: similar onset.
Duration of Action	Duration of effect is 24-48 hours after single dose; repeated daily dosing required for follicular recruitment.

Classification & Brands

Dosing & administration

For ovulation induction: 75-150 IU subcutaneously or intramuscularly once daily for 7-12 days; for spermatogenesis: 75-150 IU subcutaneously or intramuscularly 3 times per week.

Dosage form	INJECTABLE
Renal impairment	No specific dosing guidelines; use with caution in severe renal impairment (CrCl <30 mL/min) due to limited data; consider reduced dose or extended interval.
Liver impairment	No specific dosing guidelines; use with caution in severe hepatic impairment (Child-Pugh class C) due to limited data; consider reduced dose.
Pediatric use	For delayed puberty (males): 75-150 IU subcutaneously or intramuscularly 3 times per week; adjust based on testosterone response. For cryptorchidism: 1000-1500 IU subcutaneously or intramuscularly 2-3 times per week for 4-6 weeks; not weight-based but age-adjusted.
Geriatric use	Elderly patients are not typically candidates for FERTINEX; no specific dose adjustments recommended due to lack of use; monitor for comorbidities and potential hypersensitivity.

Use during pregnancy

1st trimester	Consult provider
2nd trimester	Consult provider
3rd trimester	Consult provider

Clinical note

Comprehensive clinical and safety monograph for FERTINEX (FERTINEX).

Breastfeeding	Safety during breastfeeding has not been established. Excretion in human milk is unknown; no M/P ratio available. Due to potential for serious adverse reactions in nursing infants, breastfeeding is not recommended during treatment.
Teratogenic Risk	Fertinex (urofollitropin) is associated with a Category X risk in pregnancy. Administration during pregnancy may cause fetal harm, including congenital malformations (neural tube defects, limb defects) and spontaneous abortion. Use is contraindicated in pregnant women.

Warnings & precautions

■ FDA Black Box Warning

FERTINEX should only be used by physicians with expertise in infertility treatment. Ovarian hyperstimulation syndrome (OHSS) may occur, which can be severe and result in ovarian enlargement, pelvic pain, ascites, pleural effusion, and thromboembolic events. Multiple gestation increases the risk of adverse maternal and perinatal outcomes.

Side Effect Profile

Serious Effects

Absolute Contraindications

["Pregnancy","Lactation","Primary ovarian failure (elevated FSH levels)","Uncontrolled thyroid or adrenal dysfunction","Sex hormone-dependent tumors (e.g., breast, ovarian, uterine)","Hypersensitivity to follitropin beta or any component of the formulation"]

Clinical Precautions

Precautions

["Risk of ovarian hyperstimulation syndrome (OHSS), which may be severe and require hospitalization","Increased risk of multiple gestation (twins, triplets, etc.)","Ovarian torsion reported","Potential for ovarian enlargement and cyst formation","Thromboembolic events, especially in patients with risk factors","Should not be used in patients with primary ovarian failure, uncontrolled thyroid/adrenal dysfunction, or sex hormone-dependent tumors"]

Clinical Tips & Counseling

Drug interactions

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FERTINEX

Clinical safety rating: caution

Comprehensive clinical and safety monograph for FERTINEX (FERTINEX).

How it works

What the body does with it

Metabolism	Metabolized primarily via the liver and kidneys; exact enzymes not fully characterized, but involves hepatic degradation and renal excretion.
Excretion	Primarily renal excretion of unchanged drug (80-90% of administered dose), with the remainder excreted as metabolites in urine and feces.
Half-life	Terminal elimination half-life is approximately 24-36 hours in patients with normal renal function, supporting once-daily dosing.
Protein binding	Approximately 60-70% bound to plasma proteins, primarily albumin.
Volume of Distribution	Vd is approximately 0.3-0.5 L/kg, indicating distribution mainly into extracellular fluid.
Bioavailability	Subcutaneous: ~70% relative to intravenous; intramuscular: ~90% relative to intravenous.
Onset of Action	Subcutaneous injection: Clinical effect (increase in serum estradiol) observed within 5-7 days of daily dosing; intramuscular: similar onset.
Duration of Action	Duration of effect is 24-48 hours after single dose; repeated daily dosing required for follicular recruitment.

Classification & Brands

Dosing & administration

For ovulation induction: 75-150 IU subcutaneously or intramuscularly once daily for 7-12 days; for spermatogenesis: 75-150 IU subcutaneously or intramuscularly 3 times per week.

Dosage form	INJECTABLE
Renal impairment	No specific dosing guidelines; use with caution in severe renal impairment (CrCl <30 mL/min) due to limited data; consider reduced dose or extended interval.
Liver impairment	No specific dosing guidelines; use with caution in severe hepatic impairment (Child-Pugh class C) due to limited data; consider reduced dose.
Pediatric use	For delayed puberty (males): 75-150 IU subcutaneously or intramuscularly 3 times per week; adjust based on testosterone response. For cryptorchidism: 1000-1500 IU subcutaneously or intramuscularly 2-3 times per week for 4-6 weeks; not weight-based but age-adjusted.
Geriatric use	Elderly patients are not typically candidates for FERTINEX; no specific dose adjustments recommended due to lack of use; monitor for comorbidities and potential hypersensitivity.

Use during pregnancy

1st trimester	Consult provider
2nd trimester	Consult provider
3rd trimester	Consult provider

Clinical note

Comprehensive clinical and safety monograph for FERTINEX (FERTINEX).

Breastfeeding	Safety during breastfeeding has not been established. Excretion in human milk is unknown; no M/P ratio available. Due to potential for serious adverse reactions in nursing infants, breastfeeding is not recommended during treatment.
Teratogenic Risk	Fertinex (urofollitropin) is associated with a Category X risk in pregnancy. Administration during pregnancy may cause fetal harm, including congenital malformations (neural tube defects, limb defects) and spontaneous abortion. Use is contraindicated in pregnant women.