GEREF
Clinical safety rating: caution
Comprehensive clinical and safety monograph for GEREF (GEREF).
Geref (sermorelin) is a synthetic analog of growth hormone-releasing hormone (GHRH) that stimulates the pituitary gland to release growth hormone (GH). It binds to GHRH receptors on somatotroph cells, activating adenylate cyclase and increasing intracellular cAMP, leading to GH secretion.
| Metabolism | Primarily hydrolyzed by plasma peptidases and hepatic metabolism; half-life approximately 12 minutes. |
| Excretion | Renal: 100% as unchanged drug via glomerular filtration and tubular secretion. |
| Half-life | Terminal half-life is 3-5 minutes due to rapid enzymatic degradation by peptidases; clinically, this necessitates continuous intravenous infusion for sustained effect. |
| Protein binding | Minimal (<5%), bound to albumin. |
| Volume of Distribution | 0.2-0.4 L/kg, indicating distribution primarily into extracellular fluid. |
| Bioavailability | IV: 100%; oral: negligible (<1%) due to rapid gastrointestinal degradation. |
| Onset of Action | IV: rapid (within seconds to 1 minute). |
| Duration of Action | Very short, approximately 10-15 minutes after bolus; continuous infusion required for sustained effect. |
Geref (sermorelin acetate) is administered subcutaneously at a dose of 0.5 mg once daily at bedtime.
| Dosage form | INJECTABLE |
| Renal impairment | No dose adjustment required for renal impairment; however, safety in severe renal impairment (CrCl <30 mL/min) has not been established. |
| Liver impairment | No specific dose adjustments provided for hepatic impairment; use with caution in Child-Pugh Class C. |
| Pediatric use | Pediatric patients (children with growth hormone deficiency): 0.03 mg/kg subcutaneously once daily at bedtime. Maximum dose not to exceed 1.5 mg daily. |
| Geriatric use | Geriatric use: no specific dose adjustment recommended; however, caution due to age-related renal and hepatic function decline. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for GEREF (GEREF).
| Breastfeeding | It is not known whether sermorelin is excreted in human milk. Because many drugs are excreted in human milk, caution should be exercised when Geref is administered to a nursing woman. No M/P ratio is available. Due to the lack of data, breastfeeding is not recommended during treatment with Geref. |
| Teratogenic Risk | Geref (sermorelin) is a synthetic analog of growth hormone-releasing hormone (GHRH). There are no adequate and well-controlled studies in pregnant women. Animal studies have not been conducted. Therefore, Geref should be used during pregnancy only if clearly needed. No specific risks for spontaneous abortion, major birth defects, or adverse fetal outcomes have been identified, but data are insufficient to exclude risk. The drug is not recommended for use in pregnancy due to lack of safety data. |
■ FDA Black Box Warning
None
| Serious Effects |
["Hypersensitivity to sermorelin or any component","Intracranial lesions (e.g., pituitary tumor)","Active malignancy or history of malignancy"]
| Precautions | ["Intracranial hypertension (pseudotumor cerebri) reported in children","Hypersensitivity reactions","Fluid retention and edema","Hyperglycemia and glucose intolerance","Use with caution in patients with epilepsy or migraine"] |
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| Fetal Monitoring | No specific monitoring required beyond standard obstetric care. If used during pregnancy, monitor fetal growth and development via ultrasound as indicated. Additionally, monitor maternal growth hormone and insulin-like growth factor-1 (IGF-1) levels to ensure appropriate dosing and avoid excessive stimulation. |
| Fertility Effects | Sermorelin is a GHRH analog that stimulates growth hormone secretion. Growth hormone is involved in reproductive function, and alterations in the GH/IGF-1 axis may affect fertility. However, no specific studies have evaluated the effects of Geref on fertility in humans. In animal studies, no adverse effects on fertility were observed. The clinical significance is unknown. |