Apramycin Sulfate

Aminoglycoside antibiotic Antibacterial

Dosage & Administration Guidelines

Species Route Dose Frequency Duration & Clinical Notes
Cattle (calves) Oral 20-40 mg/kg q12h Duration: 3-5 days
Notes: For treatment of colibacillosis and salmonellosis. Use oral solution or powder.
Pigs Oral 7.5-12.5 mg/kg q12h Duration: 3-5 days
Notes: For treatment of colibacillosis. Administer in drinking water or feed.
Poultry Oral (drinking water) 1 g per 10-20 L of drinking water Continuous Duration: 3-5 days
Notes: For control of colibacillosis and salmonellosis. Ensure adequate water intake.
Horse (foals) IV or IM 10-15 mg/kg q12h Duration: 3-5 days
Notes: Off-label use for neonatal septicemia. Monitor renal function.
Dog/Cat IM or SC 10-15 mg/kg q12h Duration: 3-5 days
Notes: Off-label use; not commonly used due to availability of safer alternatives.

Clinical Indications & Species Uses

General Indications
  • Treatment of gastrointestinal infections caused by susceptible Gram-negative bacteria.
  • Control of neonatal diarrhea in calves and piglets.
Horse (Equine)
  • Treatment of neonatal septicemia caused by susceptible Gram-negative bacteria (off-label).
Cattle (Bovine)
  • Treatment of bacterial enteritis caused by Escherichia coli and Salmonella spp. in calves.
  • Control of porcine colibacillosis (in pigs, but cattle are not the primary target).
Avian & Poultry
  • Treatment of colibacillosis and salmonellosis in poultry (off-label in some countries).

Pharmacology & Mechanism of Action

Drug Class: Aminoglycoside antibiotic | Pharmacological Group: Antibacterial

Mechanism of Action: Apramycin is an aminoglycoside antibiotic that acts by binding irreversibly to the 30S ribosomal subunit of susceptible bacteria, interfering with the initiation of protein synthesis. This leads to misreading of the genetic code and production of nonfunctional or toxic proteins, ultimately causing bacterial cell death. It is bactericidal and exhibits concentration-dependent killing.

Pharmacodynamics: Apramycin is active primarily against Gram-negative bacteria, including Escherichia coli, Salmonella spp., Klebsiella spp., and some Pasteurella spp. It also has activity against some Gram-positive organisms such as Staphylococcus spp. It is poorly absorbed from the gastrointestinal tract, making it effective for local action in the gut when given orally. Its activity is enhanced in an alkaline environment and is reduced in the presence of pus or acidic conditions.

⚑ Pharmacokinetics Summary

Absorption: Apramycin is poorly absorbed from the gastrointestinal tract after oral administration, with bioavailability typically less than 10%. After parenteral administration, it is rapidly and completely absorbed.
Distribution: Apramycin distributes primarily into the extracellular fluid. It does not penetrate well into the central nervous system, eyes, or prostatic fluid. It crosses the placenta and is distributed into milk. It accumulates in the renal cortex and inner ear, which is related to its nephrotoxicity and ototoxicity.
Metabolism: Apramycin undergoes minimal metabolism; it is primarily excreted unchanged.
Excretion: Apramycin is excreted primarily by glomerular filtration in the kidneys. After oral administration, most of the drug is eliminated in feces. In animals with normal renal function, the elimination half-life is short, but it is prolonged in animals with renal impairment.
Half-Life: Cattle: 2-3 hours (IV); Pigs: 2-4 hours (IM); Dogs: 1-2 hours (IV)
Bioavailability: Oral: <10% (due to poor absorption); IM: >90%
Protein Binding: Low protein binding, approximately 10-20%.

Available Formulations & Strengths

Oral Solution 100 mg/mL (Oral)
Soluble Powder 50% (500 mg/g) (Oral)
Injectable Solution 100 mg/mL (IM, IV, SC)

Contraindications & Clinical Warnings

Contraindications:
  • Hypersensitivity to apramycin or other aminoglycosides.
  • Pre-existing renal disease or hearing impairment.
  • Concurrent use with other nephrotoxic or ototoxic drugs (e.g., other aminoglycosides, loop diuretics).
  • Use in animals with severe dehydration or electrolyte imbalances.
Warnings & Clinical Precautions:
  • Use with caution in animals with renal insufficiency; monitor renal function and adjust dose if necessary.
  • Avoid prolonged use to prevent superinfection.
  • Ensure adequate hydration during therapy.
  • In food animals, observe withdrawal times.
  • Use in horses may be associated with gastrointestinal disturbances; monitor for diarrhea.
  • In poultry, ensure proper mixing to avoid underdosing or overdosing.

Adverse Effects & Reactions

Common:

  • Gastrointestinal upset (nausea, diarrhea) after oral administration.
  • Injection site pain or swelling.

Serious / Severe:

  • Nephrotoxicity (acute tubular necrosis).
  • Ototoxicity (cochlear and vestibular damage).
  • Neuromuscular blockade (respiratory depression).

Rare:

  • Allergic reactions (anaphylaxis).
  • Hepatotoxicity.

Key Drug Interactions

Interacting Drug / Class Clinical Effect & Mechanism Severity
Other aminoglycosides (e.g., gentamicin, neomycin) Additive nephrotoxicity and ototoxicity. High
Loop diuretics (e.g., furosemide) Increased risk of ototoxicity and nephrotoxicity. High
Neuromuscular blocking agents (e.g., succinylcholine) Enhanced neuromuscular blockade, leading to respiratory depression. High
Nonsteroidal anti-inflammatory drugs (NSAIDs) Increased risk of nephrotoxicity due to reduced renal blood flow. Moderate
Penicillins (e.g., ampicillin) In vitro antagonism; avoid mixing in same solution. Mild

Overdose & Toxicity Management

Signs of Toxicity:

  • Nephrotoxicity (increased BUN/creatinine, oliguria).
  • Ototoxicity (head tilt, ataxia, deafness).
  • Neuromuscular blockade (muscle weakness, respiratory depression).
  • Gastrointestinal signs (vomiting, diarrhea).

Emergency Treatment Protocol: Discontinue drug immediately. Provide supportive care: intravenous fluids to maintain hydration and promote diuresis. Monitor renal function and electrolytes. In severe cases, consider hemodialysis or peritoneal dialysis. For neuromuscular blockade, administer calcium gluconate and neostigmine (with atropine) if respiratory depression occurs.

Food Animal Withdrawal Times

πŸ₯© Meat: 28 daysπŸ₯› Milk: 7 daysπŸ₯š Eggs: 7 days

Withdrawal times may vary by country and formulation. Always follow local regulations and label instructions. For extra-label use, consult a veterinarian.

Storage, Handling & Regulatory Information

Storage Temperature: Store at controlled room temperature 15-30Β°C (59-86Β°F).

Handling & Special Conditions: Protect from freezing. Keep container tightly closed. Store in a dry place.

Dispensing Status: Prescription Required (Rx Only)

Approval Status: Approved for use in cattle and pigs in certain formulations (e.g., oral solution for calves). Not approved for use in dogs, cats, or horses in the US.

Extra-Label (Off-Label) Use: In the US, extra-label use of apramycin is permitted under AMDUCA (Animal Medicinal Drug Use Clarification Act) only by or on the order of a licensed veterinarian within a valid veterinarian-client-patient relationship. It is prohibited in feed for food-producing animals unless specifically approved.

Clinical Pearls & Practice Notes

πŸ’‘ Clinical Insights: Apramycin is a valuable antibiotic for treating enteric infections in livestock, particularly in calves and piglets. Its poor oral absorption makes it ideal for local action in the gastrointestinal tract. However, its use is limited by potential nephrotoxicity and ototoxicity, especially with parenteral administration. In companion animals, it is rarely used due to the availability of safer aminoglycosides. When using apramycin, always confirm susceptibility of the pathogen, monitor renal function, and adhere to withdrawal times in food animals. For extra-label use, follow regulatory guidelines and ensure proper dosing to minimize adverse effects.

References & Literature

  • πŸ“š Plumb's Veterinary Drug Handbook
  • πŸ“š Papich Veterinary Pharmacology and Therapeutics
  • πŸ“š Compendium of Veterinary Products (CVP)