Drug Class: Aminoglycoside Antibiotic | Form: Intramuscular (IM) / Intravenous (IV) Injection | Prescription Status: Prescription Only (Rx) — DRAP Registered
What is Grasil (Amikacin) Injection?
Grasil Injection contains Amikacin — a powerful aminoglycoside antibiotic available in two concentrations: 25mg/ml for paediatric use and 50mg/ml for adult use. It is reserved for serious, life-threatening bacterial infections that have not responded to safer first-line antibiotics, or where the infecting bacteria are known or strongly suspected to be resistant to other antibiotic classes.
Amikacin is one of the broadest-spectrum aminoglycosides available — effective against a wide range of Gram-negative bacteria and some Gram-positive organisms, including many that are resistant to Gentamicin and Tobramycin. Because of its significant potential for kidney and hearing toxicity, Grasil Injection is strictly a hospital-only medicine requiring careful dose calculation, therapeutic drug monitoring, and close organ function surveillance throughout treatment. It must be prepared and administered exclusively by trained healthcare professionals in a clinical setting.
What is Grasil Injection Used For?
Grasil Injection is approved for short-term treatment of the following serious bacterial infections:
- Lower respiratory tract infections — severe bacterial pneumonia and lung infections caused by Gram-negative organisms (پھیپھڑوں کا شدید انفیکشن)
- Bloodstream infections (septicaemia) — life-threatening bacterial infection of the blood (خون کا شدید بیکٹیریل انفیکشن)
- Bone and joint infections — osteomyelitis and septic arthritis caused by susceptible organisms (ہڈی اور جوڑ کا انفیکشن)
- Skin and soft tissue infections — serious infections not responding to standard antibiotics (جلد کا شدید انفیکشن)
- Abdominal infections — peritonitis and intra-abdominal infections, typically as part of combination therapy
- Urinary tract infections — complicated UTIs and kidney infections caused by multi-drug resistant bacteria (گردے کا شدید انفیکشن)
- Neonatal sepsis — serious bacterial infections in newborns, using the 25mg/ml paediatric concentration under strict neonatology supervision
- Burns infections — serious bacterial infections of extensive burn wounds
- Multi-drug resistant (MDR) infections — infections caused by bacteria resistant to most other available antibiotics — Amikacin is often one of the last effective options
How Does Grasil Injection Work?
Amikacin belongs to the aminoglycoside class and kills bacteria through a highly specific and irreversible mechanism. Once absorbed into the bacterial cell, Amikacin binds permanently to the 30S ribosomal subunit — the cellular machinery that bacteria use to manufacture the proteins essential for their survival and reproduction.
When Amikacin occupies this ribosomal binding site, it causes the bacterium to produce faulty, non-functional proteins — essentially corrupting the bacterial protein production process. Without correctly functioning proteins, the bacterium cannot maintain its cell membrane, regulate internal processes, or replicate. The cell membrane breaks down, critical cellular contents leak out, and the bacterium dies rapidly.
This mechanism makes Amikacin bactericidal — it actively kills bacteria rather than merely slowing their growth. Amikacin's structural modifications compared to other aminoglycosides make it resistant to most bacterial enzymes that inactivate Gentamicin and Tobramycin — explaining its superior activity against many resistant Gram-negative organisms.
Administered by injection, Amikacin achieves immediate and complete systemic distribution — reaching the bloodstream, lungs, bone tissue, peritoneal fluid, and infected organs rapidly.
Dosage and Administration
⚠️ Grasil Injection is a hospital-only medicine requiring strict dose calculation based on body weight, kidney function, and therapeutic drug monitoring. It must be prepared and administered exclusively by qualified healthcare professionals. Never attempt self-administration.
| Patient Group | Usual Dose | Frequency | Maximum Daily Dose |
|---|---|---|---|
| Adults (serious infections) | 15mg/kg/day | Every 8 – 12 hours or once daily | 1.5g/day |
| Adults (once-daily dosing) | 15 – 20mg/kg | Once daily | 1.5g |
| Children | 15 – 22.5mg/kg/day | Every 8 hours | 1.5g/day |
| Neonates (initial dose) | 10mg/kg | Then 7.5mg/kg every 12 hours | As calculated |
| Urinary tract infections (uncomplicated) | 7.5mg/kg | Every 12 hours | 1.5g/day |
Concentration Selection:
- 25mg/ml formulation — used for neonates, infants, and young children where precise small-volume dosing is required
- 50mg/ml formulation — standard adult concentration
Administration Guidelines:
- Administer as a slow IV infusion over 30 to 60 minutes for IV use — never as a rapid IV bolus
- For IM use, inject deep into a large muscle
- Therapeutic drug monitoring (TDM) is mandatory — peak and trough blood levels must be measured regularly to ensure effectiveness while preventing toxicity
- Kidney function must be assessed before starting and monitored throughout treatment — dosing intervals must be extended in patients with impaired kidney function
- Treatment duration: typically 7 to 10 days — prolonged courses significantly increase toxicity risk
- Ensure adequate patient hydration throughout treatment to protect kidney function
Active Ingredient
| Ingredient | Paediatric Strength | Adult Strength |
|---|---|---|
| Amikacin Sulphate | 25mg per ml | 50mg per ml |
Who Should NOT Receive Grasil Injection?
Do not administer if the patient:
- Is allergic to Amikacin or any other aminoglycoside antibiotic
- Has a history of aminoglycoside-induced hearing loss, tinnitus, or severe kidney damage
- Has myasthenia gravis — aminoglycosides can severely worsen neuromuscular blockade
Always inform the treating doctor before administration if the patient has:
- Kidney disease of any degree — mandatory dose adjustment and extended dosing intervals required; Amikacin is primarily eliminated by the kidneys
- Pre-existing hearing impairment or tinnitus — aminoglycosides can cause irreversible hearing loss; baseline hearing assessment is recommended
- Vestibular disorder — pre-existing balance problems can be permanently worsened
- Dehydration or low blood volume — dramatically increases kidney toxicity risk
- Neuromuscular disorders — Parkinson's disease, botulism, or other conditions affecting neuromuscular transmission
- Is pregnant — aminoglycosides can cause permanent deafness in the unborn baby; use only when no safer alternative exists for a life-threatening infection
- Is elderly — age-related reduction in kidney function greatly increases both nephrotoxicity and ototoxicity risk
Side Effects
Amikacin has a narrow therapeutic window — the difference between an effective dose and a toxic dose is small. Close monitoring is not optional — it is essential to prevent serious and potentially permanent harm.
Common Side Effects:
- Injection site pain or irritation
- Mild nausea or vomiting
- Headache or mild dizziness
Serious Toxicities — The Two Critical Risks of Aminoglycosides:
- 🔴 Nephrotoxicity (Kidney Damage) — the most common serious adverse effect; Amikacin accumulates in kidney tubule cells and causes direct damage — presenting as rising creatinine levels, reduced urination, and electrolyte disturbances. Kidney function must be tested before and repeatedly throughout treatment. Nephrotoxicity is usually reversible if detected early and treatment is modified promptly.
- 🔴 Ototoxicity (Hearing and Balance Damage) — Amikacin accumulates in the fluid of the inner ear (کان کا اندرونی حصہ) and damages cochlear hair cells — causing irreversible hearing loss (بہرا پن) that may not become apparent until after treatment ends. Balance damage (vestibular toxicity) can also occur, causing dizziness and unsteady walking. Unlike nephrotoxicity, ototoxicity is often permanent. Report any ringing in the ears (tinnitus), muffled hearing, or new dizziness immediately.
Other Serious Side Effects:
- Neuromuscular blockade — rare but potentially life-threatening respiratory muscle paralysis, particularly in patients with underlying neuromuscular disorders or those receiving anaesthetic agents
- Severe allergic reaction — sudden rash, swelling, difficulty breathing — emergency treatment required (یہ طبی ہنگامی صورتحال ہے)
- Electrolyte disturbances — low potassium, magnesium, or calcium levels from kidney tubule damage — requires monitoring and replacement
Immediately report any new ringing in the ears, hearing changes, dizziness, reduced urination, or muscle weakness to the medical team during Amikacin treatment.
Drug Interactions
| Medicine / Substance | Possible Interaction |
|---|---|
| Other aminoglycosides (e.g., Gentamicin) | Never combine — additive kidney and hearing toxicity |
| Loop diuretics (e.g., Furosemide) | Dramatically increases hearing toxicity risk — avoid combination; if essential, close audiological monitoring required |
| Vancomycin | Additive kidney toxicity — one of the most dangerous combinations; kidney function monitoring mandatory |
| Beta-lactam antibiotics (e.g., Piperacillin) | Never mix in the same IV bag or syringe — chemical inactivation occurs; administer through separate lines |
| NSAIDs (e.g., Ibuprofen, Diclofenac) | Reduce kidney blood flow — increase Amikacin accumulation and nephrotoxicity risk |
| Neuromuscular blocking agents (e.g., Vecuronium) | Amikacin potentiates neuromuscular blockade — risk of respiratory paralysis; anaesthetist must be informed |
| Ciclosporine and Tacrolimus | Additive kidney toxicity — close monitoring required |
| Amphotericin B (antifungal) | Combined kidney toxicity risk — avoid unless no alternative exists |
| Cisplatin (cancer medicine) | Additive hearing and kidney toxicity — avoid combination |
Storage Instructions
- Store below 25°C in a cool, dry place protected from light
- Do not freeze — freezing can alter the solution concentration
- Keep in original packaging until immediately before use
- Keep out of reach of children (بچوں کی پہنچ سے دور رکھیں)
- Inspect ampoule before use — solution must be clear and colourless to pale yellow; discard if discoloured or contains particles
- Use immediately once ampoule is opened — never store a partially used ampoule
- Do not use after the expiry date on the ampoule or carton
Frequently Asked Questions
Why is Amikacin used instead of Gentamicin for some infections?
Amikacin has a broader spectrum of activity than Gentamicin and is structurally modified to resist most bacterial enzymes that inactivate other aminoglycosides. This makes it effective against many multi-drug resistant Gram-negative bacteria — including resistant strains of Pseudomonas, Klebsiella, and Acinetobacter — that are no longer susceptible to Gentamicin or Tobramycin. Your doctor will select Amikacin based on culture and sensitivity results confirming the specific bacteria causing the infection and its resistance pattern.
What is therapeutic drug monitoring and why is it essential with Grasil?
Therapeutic drug monitoring (TDM) involves measuring the actual Amikacin concentration in the patient's blood at specific times after the dose — typically the peak level (highest concentration) and the trough level (lowest concentration before the next dose). Because Amikacin has a very narrow therapeutic window — the dose range between being effective and being toxic is small — TDM is essential to confirm the dose is high enough to kill the bacteria while simultaneously confirming it is not accumulating to levels that damage the kidneys or ears. Dosing is then adjusted individually based on these measured levels.
Can Amikacin cause permanent hearing loss?
Yes — this is the most serious long-term risk of Amikacin therapy and must be clearly understood. Amikacin concentrates in the fluid of the inner ear and progressively damages the delicate hair cells of the cochlea — the cells responsible for converting sound into nerve signals. Once these hair cells are destroyed, they do not regenerate — meaning the hearing loss is permanent and irreversible. High-frequency hearing is typically affected first. The risk is greater with higher doses, longer treatment durations, pre-existing hearing impairment, dehydration, and concurrent use of other ototoxic medicines such as Furosemide. Report any tinnitus or hearing change to your doctor immediately during treatment.
Why are two different concentrations of Grasil available?
The 25mg/ml paediatric concentration is designed for accurate dosing in neonates, infants, and young children where the required dose per kg of body weight results in very small volumes that must be measured with precision. Using the adult 50mg/ml concentration in very small patients would require impractically tiny, difficult-to-measure volumes — increasing the risk of dosing errors. The 25mg/ml concentration allows safer, more accurate volume measurement for smaller patients. The 50mg/ml adult concentration is appropriate for older children, adolescents, and adults where larger total doses are required.
How is kidney function monitored during Grasil treatment?
Before starting Amikacin, baseline kidney function is measured through blood tests — specifically serum creatinine and blood urea nitrogen — and urine output is assessed. During treatment, these tests are repeated every 2 to 3 days or more frequently in high-risk patients. Any significant rise in creatinine, fall in urine output, or electrolyte disturbance signals early kidney damage and requires immediate reassessment of the dose, dosing interval, or continuation of treatment. Patients must also be kept well hydrated throughout the treatment course — dehydration dramatically increases the risk of aminoglycoside kidney toxicity.
⚕️ Medical Disclaimer: This product description is provided for general informational purposes only and does not replace professional medical advice, diagnosis, or treatment. Grasil Injection is a prescription-only hospital medicine requiring strict therapeutic drug monitoring and organ function surveillance. It must be administered exclusively by qualified healthcare professionals. Report any hearing changes, tinnitus, reduced urination, or muscle weakness to the medical team immediately during treatment.
DRAP Registered | Prescription Required (Rx) | Hospital use only — mandatory kidney function and drug level monitoring throughout treatment — report any hearing changes immediately