Drug Class: Aminoglycoside Antibiotic | Form: Intramuscular (IM) / Intravenous (IV) Injection | Prescription Status: Prescription Only (Rx) — DRAP Registered
What is Grasil 50mg Injection?
Grasil 50mg Injection contains Amikacin Sulphate — a powerful aminoglycoside antibiotic in a lower-strength formulation designed primarily for neonates, infants, and young children where precise, small-volume dosing is clinically essential. Each vial delivers 50mg of Amikacin — suitable for patients whose weight-based dose requirements are smaller than those of older children and adults.
Amikacin is one of the most broad-spectrum aminoglycosides available and is specifically valued for its effectiveness against multi-drug resistant (MDR) Gram-negative bacteria — including resistant strains of Pseudomonas aeruginosa, Klebsiella, Acinetobacter, and Enterobacter — organisms that frequently cause the most serious hospital-acquired and community infections in Pakistan. Its structural design makes it resistant to most bacterial enzymes that inactivate other aminoglycosides like Gentamicin, making Grasil 50mg a critical last-resort or directed-therapy option when bacterial culture and sensitivity results confirm its necessity.
This is strictly a hospital-only medicine. It carries a well-defined and serious toxicity profile — particularly for the kidneys and hearing — requiring mandatory therapeutic drug monitoring, kidney function testing, and close clinical supervision throughout the entire course of treatment.
What is Grasil 50mg Injection Used For?
Grasil 50mg Injection is approved for the short-term treatment of the following serious bacterial infections caused by susceptible organisms:
- Respiratory tract infections — severe bacterial pneumonia and lower respiratory tract infections caused by Gram-negative organisms (پھیپھڑوں کا شدید انفیکشن)
- Septicaemia — life-threatening bacterial infection of the bloodstream (خون کا شدید بیکٹیریل انفیکشن) including neonatal sepsis
- Bone and joint infections — osteomyelitis and septic arthritis caused by susceptible bacteria (ہڈی اور جوڑ کا انفیکشن)
- Skin and soft tissue infections — serious infections not responding to standard antibiotics (جلد کا شدید انفیکشن)
- Urinary tract infections — complicated UTIs and kidney infections caused by multi-drug resistant Gram-negative bacteria
- Abdominal infections — peritonitis and intra-abdominal sepsis, typically as part of combination antibiotic therapy
- Neonatal sepsis — serious bacterial infections in newborns where precise low-dose administration is required
- Multi-drug resistant infections — infections confirmed resistant to broader first-line antibiotic options where Amikacin sensitivity is confirmed on culture
How Does Grasil 50mg Injection Work?
Amikacin kills bacteria through a precise and irreversible mechanism targeting bacterial protein synthesis — a process essential for bacterial survival and reproduction.
Once Amikacin enters the bacterial cell, it binds permanently to the 30S ribosomal subunit — the molecular machinery bacteria use to assemble proteins. This binding corrupts the protein manufacturing process, causing bacteria to produce defective, non-functional proteins. Without correctly functioning proteins, bacteria cannot maintain their cell membranes, regulate internal processes, or reproduce — leading to rapid bacterial cell death.
This mechanism makes Amikacin bactericidal — it actively kills bacteria rather than simply inhibiting their growth. Its modified chemical structure resists most bacterial aminoglycoside-inactivating enzymes — explaining its superior effectiveness against organisms resistant to Gentamicin and Tobramycin.
When administered by injection, Amikacin achieves rapid systemic distribution — reaching the bloodstream, lungs, bone tissue, peritoneal fluid, and infected organs within minutes, with no dependence on gastrointestinal absorption.
Dosage and Administration
⚠️ Grasil 50mg Injection is a hospital-only medicine. All doses must be individually calculated based on body weight and kidney function. Therapeutic drug monitoring is mandatory. Must be prepared and administered exclusively by qualified healthcare professionals.
| Patient Group | Dose | Frequency | Typical Duration |
|---|---|---|---|
| Neonates (0 – 7 days) | 10mg/kg loading, then 7.5mg/kg | Every 12 hours | 7 – 10 days |
| Neonates (over 7 days) | 10mg/kg | Every 8 – 12 hours | 7 – 10 days |
| Infants and children | 15 – 22.5mg/kg/day | Divided every 8 hours | 7 – 10 days |
| Adults (where 50mg vials are used) | As calculated by clinical team | Every 8 – 12 hours or once daily | Maximum 10 days |
| Kidney-impaired patients | Dose reduction and extended intervals | As calculated | Individually determined |
Administration Guidelines:
- Administer IV doses as a slow infusion over 30 to 60 minutes — never as a rapid IV bolus injection
- For IM administration, inject deep into a large muscle with careful site rotation
- Therapeutic drug monitoring (TDM) is mandatory — peak and trough Amikacin blood levels must be measured and doses adjusted accordingly
- Kidney function must be tested before starting and monitored every 2 to 3 days throughout treatment
- Ensure adequate patient hydration throughout the course — dehydration dramatically increases nephrotoxicity risk
- Maximum treatment duration: 10 days — prolonged courses significantly increase the risk of irreversible hearing and kidney damage
Active Ingredient
| Ingredient | Strength per Vial |
|---|---|
| Amikacin Sulphate | 50mg |
Who Should NOT Receive Grasil 50mg 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 severely worsen neuromuscular blockade and can cause respiratory failure
Always inform the treating doctor before administration if the patient has:
- Any degree of kidney impairment — dose reduction and extended intervals are mandatory; Amikacin is eliminated entirely through the kidneys
- Pre-existing hearing loss or tinnitus — existing inner ear damage makes further aminoglycoside ototoxicity risk substantially higher
- Dehydration or low blood volume — dramatically increases nephrotoxicity risk; correct fluid status before starting treatment
- Neuromuscular disorders — conditions affecting nerve-muscle transmission increase the risk of dangerous neuromuscular blockade
- Is pregnant — Amikacin crosses the placenta and can cause permanent deafness in the unborn baby; use only when a life-threatening infection leaves no safer alternative
- Is elderly — age-related kidney function decline greatly increases both nephrotoxicity and ototoxicity risk
Side Effects
Amikacin has a narrow therapeutic window — the margin between an effective dose and a toxic dose is small. The two most serious risks are kidney toxicity and irreversible hearing loss. Both require active monitoring throughout the entire treatment course.
Common Side Effects:
- Injection site pain, redness, or localised swelling
- Mild nausea or vomiting
- Headache or mild dizziness
The Two Critical Toxicities:
🔴 Nephrotoxicity (Kidney Damage) — Amikacin accumulates in kidney tubule cells and causes direct cellular damage — presenting as rising creatinine levels, reduced urination, and electrolyte disturbances. Kidney function tests must be performed before and every 2 to 3 days during treatment. Nephrotoxicity is usually reversible if detected early and treatment is modified promptly — but can progress to acute kidney failure if missed.
🔴 Ototoxicity (Hearing and Balance Damage) — Amikacin concentrates in the inner ear fluid (کان کا اندرونی حصہ) and permanently destroys cochlear hair cells — causing irreversible high-frequency hearing loss (بہرا پن) that may not become apparent until after treatment ends. Vestibular damage causing dizziness and balance problems can also occur. Unlike nephrotoxicity, hearing loss from Amikacin is permanent and cannot be reversed. Any ringing in the ears (tinnitus), muffled hearing, or new dizziness during treatment must be reported to the medical team immediately.
Other Serious Side Effects:
- Neuromuscular blockade — rare but potentially fatal respiratory muscle paralysis, particularly in patients with neuromuscular conditions or those receiving anaesthetic agents
- Severe allergic reaction — sudden rash, swelling of face or throat, difficulty breathing — emergency treatment required (یہ طبی ہنگامی صورتحال ہے)
- Electrolyte disturbances — low potassium, magnesium, or calcium caused by kidney tubule damage — requires monitoring and replacement
Drug Interactions
| Medicine / Substance | Possible Interaction |
|---|---|
| Other aminoglycosides (e.g., Gentamicin, Tobramycin) | Never combine — additive and severe kidney and hearing toxicity |
| Loop diuretics (e.g., Furosemide) | Dramatically increases irreversible hearing toxicity — avoid combination; if unavoidable, audiological monitoring is mandatory |
| Vancomycin | Additive nephrotoxicity — one of the most dangerous combinations in clinical practice; kidney function monitoring mandatory |
| Beta-lactam antibiotics (e.g., Piperacillin, Carbenicillin) | Never mix in the same syringe or IV bag — chemical inactivation of both medicines; administer through separate lines with adequate flushing |
| NSAIDs (e.g., Diclofenac, Ibuprofen) | Reduce kidney blood flow — increase Amikacin accumulation and nephrotoxicity risk |
| Neuromuscular blocking agents (e.g., Vecuronium, Suxamethonium) | Amikacin potentiates neuromuscular blockade — risk of prolonged respiratory paralysis; anaesthetist must be informed before any procedure |
| Ciclosporine and Tacrolimus | Additive nephrotoxicity — avoid combination or monitor kidney function very closely |
| Cisplatin (cancer medicine) | Additive hearing and kidney toxicity — avoid concurrent use |
| Amphotericin B (antifungal) | Combined nephrotoxicity — use together only when no safer alternative exists |
Storage Instructions
- Store below 25°C in a cool, dry place protected from direct light
- Do not freeze — freezing alters solution integrity
- Keep in original packaging until immediately before use
- Keep out of reach of children (بچوں کی پہنچ سے دور رکھیں)
- Inspect vial before use — solution must be clear and colourless to pale yellow; discard if discoloured or particles are visible
- Use immediately once opened — never store a partially used vial
- Do not use after the expiry date printed on the vial or carton
Frequently Asked Questions (FAQs)
Why is the 50mg vial used instead of the higher-strength Amikacin formulations?
The 50mg vial is specifically designed for patients — primarily neonates, infants, and small children — whose weight-based dose requirements result in very small volumes. Using a higher-concentration vial such as 250mg/ml in these patients would require impractically tiny volumes that are extremely difficult to measure accurately, significantly increasing the risk of dosing errors. The 50mg vial allows safer, more precise volume measurement for smaller patients, reducing both under-dosing (treatment failure) and over-dosing (toxicity risk). The treating paediatrician or neonatologist will select the appropriate concentration and calculate the exact volume per dose.
What is therapeutic drug monitoring and why is it mandatory with Amikacin?
Therapeutic drug monitoring (TDM) involves measuring Amikacin blood concentrations at specific times — typically the peak level after a dose and the trough level before the next dose. Because Amikacin has a very narrow therapeutic window — meaning effective doses and toxic doses are close together — TDM is the only reliable way to confirm that each individual patient is receiving enough antibiotic to kill the bacteria while not accumulating to levels that damage the kidneys or inner ear. Doses are then individually adjusted based on these measured levels and the patient's kidney function. TDM is not optional for Amikacin therapy — it is a mandatory clinical safety requirement.
Can Amikacin cause permanent hearing loss?
Yes — this is the most serious long-term risk of Amikacin therapy and must be clearly understood by patients and families. Amikacin accumulates in the fluid of the inner ear and progressively destroys cochlear hair cells — the cells responsible for converting sound into nerve signals. Once destroyed, these cells do not regenerate — making the hearing loss permanent and irreversible. High-frequency hearing is typically affected first, often before the patient notices any change. Risk is substantially higher with longer treatment, higher doses, dehydration, pre-existing hearing impairment, and concurrent ototoxic medicines like Furosemide. Any ringing in the ears, muffled sounds, or new dizziness must be reported to the medical team immediately during treatment.
Why must Amikacin never be mixed in the same IV line as Penicillin-type antibiotics?
Amikacin and beta-lactam antibiotics such as Piperacillin or Ampicillin are chemically incompatible — when mixed together in the same syringe, IV bag, or line, they undergo a direct chemical reaction that inactivates both medicines simultaneously. This means neither antibiotic reaches the patient at its intended therapeutic concentration — potentially resulting in treatment failure for a life-threatening infection. They must always be administered through separate IV lines, or the shared line must be thoroughly flushed with compatible fluid between each medicine. The clinical pharmacist will advise on compatible administration sequences.
How long can Amikacin be safely used?
The recommended maximum treatment duration is 7 to 10 days. Prolonged use beyond this period substantially increases the cumulative risk of both irreversible hearing loss and permanent kidney damage — as Amikacin continues to accumulate in inner ear and kidney cells with ongoing exposure. If the clinical situation requires continued antibiotic coverage beyond 10 days, the treating doctor will reassess whether Amikacin remains necessary or whether transition to a less toxic antibiotic is possible based on culture sensitivity results.
Is Grasil 50mg Injection safe during pregnancy?
Amikacin should be avoided during pregnancy unless a life-threatening bacterial infection leaves absolutely no safer alternative. Amikacin crosses the placental barrier and can concentrate in the developing baby's inner ear — causing permanent congenital hearing loss in the unborn child. This risk applies even at doses that are considered safe for the mother. If Amikacin is unavoidable in a pregnant patient, the decision must be made jointly by the infectious disease specialist and obstetrician, with full informed discussion of the risk, and the shortest possible course at the lowest effective dose must be used.
⚕️ Medical Disclaimer: This product description is provided for general informational purposes only and does not replace professional medical advice, diagnosis, or treatment. Grasil 50mg Injection is a prescription-only hospital medicine requiring mandatory therapeutic drug monitoring and continuous organ function surveillance. It must be administered exclusively by qualified healthcare professionals. Report any new hearing changes, tinnitus, reduced urination, or muscle weakness to the medical team immediately.
DRAP Registered | Prescription Required (Rx) | Hospital use only — mandatory kidney function and drug level monitoring throughout treatment — report any hearing or urinary changes immediately