buserelin

Action and Spectrum

Actions and Spectrum: 

Actions: 

In the pituitary gland, buserelin binds to the GnRH receptor and shows its action by the increase, which is transient where LH and FSH are released from the pituitary gland. Still, if buserelin is administered continuously, then it shows its action, which suppresses the release and production of testosterone (Men)  and estrogen (Women). 

Spectrum: 

The spectrum of buserelin is indicated for the treatment of Endometriosis, advanced prostate cancer, breast cancer, and adjunctive therapy in the induction of ovulation. 

Drug Interaction

Adverse Reaction

Frequency defined 

>10% 

Headache (20-29%) 

Impotence (implant: 2%; SC/nasal: 75-79%) 

Back pain (28%) 

Decreased libido (intranasal: 12%; implant: 2%) 

Flatulence (15%) 

Vaginal dryness (29%) 

Loss of libido (SC: 85%; intranasal: 75%) 

Injection site reactions (SC: 12%; implant: 1%) 

Hot flash (SC/nasal: 66-72%; implant: 16%) 

Heavy menstrual bleeding (24%) 

1-10% 

Dry nose (nasal: 2%) 

Arthralgia (5%) 

Anxiety (1%) 

Sleep disorder (1%) 

Limp pain (2%) 

Neck stiffness (1%) 

Myalgia (2%) 

Asthenia (nasal: 7%; implant: <1%) 

Paresthesia (2%) 

Migraine (3%) 

Dyspareunia (2%) 

Vaginitis (2%) 

Mastalgia (females: 3%) 

Edema (nasal: 3-6%; implant: 1%) 

Pruritis (SC/implant: <1%) 

Acne vulgaris (5%) 

HTN (implant: 2%) 

Xeroderma (2%) 

Diaphoresis (implant/nasal: <2%) 

Palpitations (1%) 

Gynecomastia (males: SC: 3%; implant: <1%) 

Weight gain (nasal: 3%; implant: <1%) 

Constipation (nasal/implant: <1%) 

Purpuric disease (1%) 

Hirsutism (nasal/SC: <1%) 

Dysgeusia (2%) 

Nausea (SC/implant: <1%; nasal: 7%) 

Menstrual disease (1%) 

Infection (7%) 

Depression (nasal: 2%; implant: 2%) 

Hostility (1%) 

Dizziness (9%) 

Emotional liability (7%) 

<1% 

Fever 

Muscle cramps (implant) 

Heart failure (implant) 

Vasodilation 

Skin rash 

Abdominal pain  

Myelofibrosis (implant) 

Hypersensitivity reaction 

Bleeding at injection site (implant) 

Pharyngitis (implant) 

Tinnitus  

Dry eye syndrome 

Otalgia 

Dyspnea (implant) 

Accommodation disturbance 

Tremor 

Transient blindness (implant) 

Abnormal thinking 

Amnesia 

Vertigo 

Epistaxis 

Sucidal tendencies 

Drowsiness 

Altered sense of smell 

Myopathy (implant) 

Urinary retention (SC) 

Breast atrophy 

Pelvic pain 

Genital pain (male:implant) 

Fecal incontinence (implant) 

Oral mucosa ulcer 

Skin photosensitivity 

Tachycardia (implant) 

Breast hypertrophy 

Thrombophlebitis (implant) 

Hyperglycemia (implant) 

Ejaculatory disorder (implant) 

Vaginal hemorrhage 

Genital pain (male: implant) 

Increased appetite  

Gastrointestinal pain 

Black Box Warning

Black Box Warning: 

Patients who are on buserelin should not drive or operate machinery. Nasal decongestants should be avoided 30 minutes prior to and after the administration of treatment with buserelin. 

Contraindication / Caution

Contraindication/Caution: 

Contraindications 

• Hypersensitivity 
• Pregnancy 
• Breastfeeding 
• Orchiectomy 
• Undiagnosed abnormal vaginal bleeding 

Cautions 

• Diabetes mellitus 
• Urinary obstruction 
• Cardiovascular disease 
• Endometriosis 
• Polycystic ovarian syndrome 
• History of QT prolongation 
• Depression 

Pregnancy / Lactation

Pregnancy consideration:  

buserelin should be avoided in pregnancy. 

Breastfeeding warnings:  

buserelin should be avoided in breastfeeding women. 

Pregnancy category: 

Category A: well-controlled and satisfactory studies show no risk to the fetus in the first or later trimester. 

Category B: there was no evidence of risk to the fetus in animal studies, and there were not enough studies on pregnant women. 

Category C: there was evidence of risk of adverse effects in animal reproduction studies, and no adequate evidence in human studies must take care of potential risks in pregnant women.    

Category D: adequate data with sufficient evidence of human fetal risk from various platforms, but despite the potential risk, and used only in emergency cases for potential benefits.    

Category X: Drugs listed in this category outweigh the risks over benefits. Hence these categories of drugs need to be avoided by pregnant women.    

Category N: No data is available for the drug under this category. 

Pharmacology

Pharmacology: 

In the pituitary gland, buserelin binds to the GnRH receptor and shows its action by the increase, which is transient where LH and FSH are released from the pituitary gland. Still, if buserelin is administered continuously, then it shows its action, which suppresses the release and production of testosterone (Men)  and estrogen (Women). 

Pharmacodynamics: 

When follicle-stimulating hormone and pituitary gonadotropins luteinizing hormone elevated administration of buserelin will result in the hypothalamic-pituitary-gonadal axis downward regulation, resulting in the decrease in secretion of sex hormone, it will take ten days (3-month depot) after onset when testosterone reaches castrate level. 

Pharmacokinetics: 

Absorption 

The bioavailability is 70% via SC, nasal: 1-3% 

The time to achieve peak effect is in plasma: < 10 days (3-month depot), nasal: 1 hour 

Distribution 

Protein-bound is 15% 

Metabolism 

buserelin is metabolized to inactive metabolites via peptidase. 

Elimination and Excretion 

The half-life is 1-1.2 hours, SC: 1.1.2 hours, implants: 20-30 days, nasal: 1-2 hours. 

The drug is excreted in feces and urine. 

Adminstartion

Administration: 

Under the supervision of a doctor in a clinical setup, buserelin is administered usually as an SC injection or as an intranasal spray. Depending on the response, the dose is decided. 

Patient Information Leaflet

Patient information leaflet 

Generic Name: buserelin 

Pronounced: Byoo-SER-uh-lin 

Why do we use buserelin? 

buserelin is a GnRH agonist/LHRH agonist used in the treatment of Endometriosis, adjunctive therapy in induction of ovulation, and advanced prostate carcinoma.