Nandrolone Decanoate
Nandrolone decanoate is an **injectable anabolic steroid** historically used in veterinary medicine to stimulate **erythropoiesis** in patients with certain anemias (e.g., secondary to chronic renal failure or aplastic anemias) and as an **appetite stimulant**. * **Clinical Shift:** Anabolic steroids are rarely recommended or used today in veterinary medicine due to the availability of safer and more targeted therapies (e.g., recombinant human erythropoietin/darbepoetin for anemia, and mirtazapine or capromorelin for appetite stimulation). * **Regulatory Status:** It is a **C-III Controlled Substance** due to the high potential for human abuse. * **Availability:** There are currently no FDA-approved commercial products marketed in the USA for veterinary or human use; it may only be available through compounding pharmacies.
Mechanism: Nandrolone is a synthetic derivative of testosterone with enhanced anabolic and reduced androgenic properties. * **Anabolic Effects:** Binds to intracellular **androgen receptors (AR)** โ translocates to the nucleus โ alters gene transcription. In the presence of adequate protein and calories, it promotes body tissue-building processes and reverses catabolism. * **Erythropoiesis Stimulation:** Enhances red blood cell counts by directly stimulating red cell precursors in the bone marrow, increasing red cell **2,3-diphosphoglycerate (2,3-DPG)**, and stimulating **erythropoietin (EPO)** production in the kidneys. * **Endocrine Feedback:** Suppresses endogenous testosterone release by inhibiting **luteinizing hormone (LH)**. Large doses impede spermatogenesis via negative feedback inhibition of **follicle-stimulating hormone (FSH)**. * **Metabolic Effects:** Causes retention of nitrogen, sodium, potassium, and phosphorus, and decreases urinary excretion of calcium.
Dosing by species
- FeLV-induced anemia or as a general bone marrow stimulant ยท 10-20 mg IM once weekly ยท IM ยท once weekly ยท Is of questionable benefit.
- Chronic anemia secondary to feline cardiomyopathy ยท 50 mg IM weekly ยท IM ยท weekly
- Adjunctive treatment of chronic idiopathic myelofibrosis ยท 2 mg/kg IM weekly ยท IM ยท weekly ยท 3 weeks ยท Used with prednisolone (2-3 mg/kg PO once daily for 3-4 weeks, then tapered). If anemia does not respond, azathioprine may be added.
- Disuse muscle atrophy secondary to immobilization ยท 1.5 mg/kg IM once weekly ยท IM ยท once weekly ยท up to 8 weeks ยท Start from the day of surgery/immobilization.
- Treatment of anemia in patients with chronic renal failure ยท 1-1.5 mg/kg IM once weekly ยท IM ยท once weekly ยท May require 2-3 months to achieve beneficial effects ยท Evidence to support use is poor.
- Treatment of anemia in patients with chronic renal failure ยท 5 mg/kg IM (maximum of 200 mg/week) every 2-3 weeks ยท IM ยท every 2-3 weeks
- Treatment of metabolic and endocrine anemias ยท 5 mg/kg IM once weekly ยท IM ยท once weekly ยท Maximum of 200 mg. Most resolve with correction of underlying disease process.
- Aplastic anemia ยท 1-3 mg/kg IM weekly ยท IM ยท weekly
- Appetite stimulant ยท 5 mg/kg IM weekly ยท IM ยท weekly ยท Maximum 200 mg/week.
Routes of administration
Contraindications
- Hepatic dysfunction
- Hypercalcemia
- History of myocardial infarction
- Pituitary insufficiency
- Prostate carcinoma
- Mammary carcinoma
- Benign prostatic hypertrophy (BPH)
- Nephrotic stage of nephritis
- Pregnancy (FDA Category X - known teratogen)
Adverse effects
- Sodium, calcium, potassium, water, chloride, and phosphate retention
- Hepatotoxicity
- Behavioral changes (androgenic effects, e.g., increased aggression)
- Reproductive abnormalities (oligospermia, estrus suppression)
- Masculinization of female fetuses (teratogenic)
Drug interactions
- Anticoagulants (e.g., warfarin) ยท Anabolic agents may potentiate the effects of anticoagulants; monitoring of INR and dosage adjustment of the anticoagulant are recommended.
- Corticosteroids, ACTH ยท Anabolics may enhance the edema that can be associated with ACTH or adrenal steroid therapy.
- Insulin ยท Anabolics may decrease blood glucose and decrease insulin requirements; diabetic patients may need dosage adjustments.
Monitoring
- Androgenic side effects (behavioral changes)
- Fluid and electrolyte status (especially sodium, potassium, calcium)
- Liver function tests (AST, ALT, ALP, bilirubin)
- Red blood cell count and indices
- Weight and appetite
Overdose
No specific information was located for this agent in veterinary species. In humans, **sodium and water retention** can occur after overdosage of anabolic steroids. * **Treatment:** Treat supportively. Monitor liver function and electrolyte status should an inadvertent overdose be administered.
VetSheet drug reference is intended for licensed veterinary professionals as a clinical decision-support aid, not a substitute for professional judgement or the manufacturerโs current label.