Finasteride
Finasteride is used in veterinary medicine for benign prostatic hyperplasia in dogs.
Group
5-alpha-reductase inhibitor
Mechanism of Action
Reduces testosterone conversion to dihydrotestosterone and decreases prostatic growth.
Dose Rates
Dog
| Use / stage | Dose | Route | Schedule | Instructions |
|---|---|---|---|---|
| Benign prostatic hyperplasia | 0.1 mg/kg | PO | Every 24 h | Do not use in: Pregnancy |
| Benign prostatic hyperplasia | 0.1–0.5 mg/kg | PO | Every 24 h | Do not use in: Pregnancy; Alternative studied range. |
| Benign prostatic hyperplasia | 5 mg/animal | PO | Every 24 h | Do not use in: Pregnancy; Source fixed regimen for dogs weighing 10–50 kg. |
| Size-selected prostatic hyperplasia regimen | Reference only | PO | Alternative daily fixed amounts: 1.5 mg if under 15 kg, 2.5 mg at 15–30 kg, or 5 mg above 30 kg. The source describes 1.5 mg as approximately one-third of a 5 mg tablet, which is arithmetically inexact; the milligram amount and fraction must not be treated as equal. |
Ferret
| Use / stage | Dose | Route | Schedule | Instructions |
|---|---|---|---|---|
| Adrenal-disease adjunct | 5 mg | PO | Every 24 h |
Indications
- Benign prostatic hyperplasia in dogs
Contraindications
- Pregnancy
- Food-producing animals
Interactions
- May be used with an alpha-blocker such as tamsulosin.
Adverse effects
- No specific canine adverse effects reported in the supplied limited studies.
Preparations
| Preparation | Form | Strength | Route |
|---|---|---|---|
| Finasteride 1 mg | Tablet | 1 mg / tablet | PO |
| Finasteride 5 mg | Tablet | 5 mg / tablet | PO |
Monitoring and Administration
Assess prostate size and clinical signs; semen quality and testosterone production were preserved in cited canine studies.