Deslorelin
**Deslorelin acetate** is a potent synthetic analog of gonadotropin-releasing hormone (GnRH). It is utilized in veterinary medicine for two seemingly opposite purposes, depending on the formulation and duration of exposure: * **Short-term use (Ovulation Induction):** In mares, short-acting injectable suspensions or removable implants are used to induce and precisely time ovulation, facilitating successful breeding. * **Long-term use (Medical Castration/Contraception):** Sustained-release implants provide continuous GnRH stimulation, which ultimately suppresses the reproductive axis. This is used for reversible contraception in male dogs, and off-label for managing benign prostatic hyperplasia (BPH) and incontinence in ovariectomized dogs. > **Clinical Pearl:** Although not explicitly labeled in all regions, deslorelin implants (Suprelorin) are widely considered the gold standard treatment for **adrenal gland disease in ferrets** and are frequently used off-label for reproductive control in exotic species and zoo animals.
Mecanismo: Deslorelin acts as an agonist at **GnRH receptors** in the anterior pituitary gland. Its clinical effect depends entirely on the duration of administration: * **Acute Administration (Flare Effect):** Initial binding to GnRH receptors stimulates a rapid surge in the release of **luteinizing hormone (LH)** and **follicle-stimulating hormone (FSH)**. * *Pathway:* Deslorelin → Pituitary GnRH receptors → ↑ LH/FSH surge → **Induction of ovulation** (in mares with mature follicles >30 mm). * **Continuous Administration (Downregulation):** When provided as a sustained-release implant, the continuous presence of the GnRH analog overstimulates the receptors. * *Pathway:* Continuous deslorelin → **Internalization and downregulation of GnRH receptors** → Profound suppression of LH and FSH secretion → Decreased production of gonadal steroids (testosterone/estrogen) → **Reversible chemical castration/contraception**.
Dosificación por especie
- Induction of ovulation (follicle 30-40 mm in diameter) · 1.8 mg (1 mL) · IM · Once · Single dose · Administer in the neck. Shake vial well before drawing into syringe.
- Induction of ovulation (follicle >30 mm in diameter) · 1 implant (2.1 mg) · SC · Once · Remove after 48h · Implant SC in the neck. Remove after approx 48 hours to prevent prolonged interovulatory interval. Alternative: Infuse 1 mL lidocaine into vulvar edge, insert implant beneath epithelium. Squeeze out after ovulation.
- Contraceptive in male dogs · 4.7 mg implant SC every 6 months OR 9.4 mg implant SC every 12 months · SC · q6mo or q12mo · Continuous · Implant in loose skin between lower neck and lumbar area; avoid implanting into fat. Pregnant women should not administer the implant.
- Temporary chemical castration · 1 implant (4.7 mg or 9.4 mg) per male dog · SC · repeat after 6 or 12 months · 6 to 12 months depending on implant size · Dogs <10 kg may take up to 18 months to recover testosterone. Separation from females in heat required for first 6 weeks.
- Temporary chemical castration · 1 implant (4.7 mg) per male cat · SC · once · 2-4 years · Causes chemical castration for 2-4 years in tom cats.
Las dosis son una referencia clínica para médicos veterinarios. Confirme siempre con la información vigente del producto y el paciente individual.
Vías de administración
Contraindicaciones
- Known hypersensitivity to deslorelin
- Horses intended for human consumption
- Intravenous (IV) administration
- Administration by pregnant women (implants)
Efectos adversos
- Local swelling, pain, and elevated skin temperature at the injection/implant site (usually resolves within 5 days)
- Prolonged interovulatory period in mares if the 2.1 mg implant is not removed
- Initial transient increase in sexual behavior or clinical signs (flare effect) before suppression occurs (with long-acting implants)
Monitoreo
- Follicle size via ultrasound or rectal palpation (mares)
- Injection/implant site for severe swelling or reaction
- Resolution of clinical signs or reduction in testicular size (when used for contraception in dogs)
Sobredosis
In mares receiving a single IM injection at 10X the recommended dose (18 mg), moderate tremors and hives were observed 6 hours after injection in one out of eight horses. If an inadvertent additional implant is administered, it should be removed upon detection if within 96 hours of implantation.
La referencia de fármacos de VetSheet está destinada a médicos veterinarios como apoyo a la decisión clínica; no sustituye el juicio profesional ni la información vigente del fabricante.