Grasil 250mg Injection (Amikacin Sulphate)

Drug Class: Aminoglycoside Antibiotic | Form: Intramuscular (IM) / Intravenous (IV) Injection | Prescription Status: Prescription Only (Rx) — DRAP Registered

What is Grasil 250mg Injection?

Grasil 250mg Injection contains Amikacin Sulphate — a powerful aminoglycoside antibiotic in the highest standard clinical strength, delivering 250mg of Amikacin per vial. This is the primary formulation used for adults and larger patients requiring the full weight-based therapeutic dose of Amikacin in a single, conveniently measured vial — making it the most widely used Amikacin strength in adult hospital wards, intensive care units, and emergency settings across Pakistan.

At 250mg per vial, Grasil 250mg achieves the high systemic antibiotic concentrations required to effectively combat the most serious, life-threatening Gram-negative bacterial infections — including multi-drug resistant (MDR) organisms that have failed to respond to multiple other antibiotic classes. It is specifically reserved for severe infections where culture and sensitivity testing has confirmed Amikacin as an appropriate or last-resort treatment option, or where clinical urgency demands empirical coverage of resistant Gram-negative organisms while awaiting laboratory results.

As with all Amikacin formulations, Grasil 250mg carries a well-defined and serious toxicity profile. The higher dose delivered per vial means that precise weight-based calculation, mandatory therapeutic drug monitoring, and continuous kidney function and hearing surveillance are even more critical at this strength than at lower formulations. This is strictly a hospital-only medicine requiring preparation and administration exclusively by qualified healthcare professionals.

What is Grasil 250mg Injection Used For?

Grasil 250mg Injection is approved for short-term treatment of the following serious bacterial infections caused by susceptible organisms:

• Septicaemia — life-threatening bacterial bloodstream infection requiring immediate, high-concentration systemic antibiotic coverage (خون کا شدید بیکٹیریل انفیکشن) including Gram-negative sepsis and hospital-acquired bacteraemia
• Respiratory tract infections — severe bacterial pneumonia, hospital-acquired pneumonia, and ventilator-associated pneumonia caused by MDR Gram-negative organisms (پھیپھڑوں کا شدید انفیکشن)
• Bone and joint infections — osteomyelitis and septic arthritis caused by susceptible organisms requiring prolonged high-dose antibiotic therapy (ہڈی اور جوڑ کا انفیکشن)
• Intra-abdominal infections — peritonitis, abdominal cavity sepsis, and post-surgical abdominal infections — typically combined with anaerobic coverage such as Metronidazole
• Urinary tract infections — complicated UTIs and pyelonephritis caused by MDR Gram-negative bacteria resistant to all oral and standard injectable options (گردے کا شدید انفیکشن)
• Skin and soft tissue infections — serious or necrotising infections involving resistant Gram-negative organisms (جلد کا شدید انفیکشن)
• Burns infections — serious bacterial infections complicating extensive burn wounds — Pseudomonas aeruginosa coverage is particularly important in burns patients
• Multi-drug resistant infections — infections caused by organisms including resistant Pseudomonas, Acinetobacter, Klebsiella, and Enterobacter confirmed susceptible to Amikacin on culture and sensitivity testing

How Does Grasil 250mg Injection Work?

Amikacin kills bacteria through a precise, irreversible mechanism targeting bacterial protein synthesis — the process fundamental to bacterial survival, structural integrity, and reproduction.

Once Amikacin enters the bacterial cell, it binds permanently to the 30S ribosomal subunit — the molecular machinery that assembles proteins from amino acid chains. This permanent binding corrupts the entire protein production process — causing bacteria to manufacture defective, non-functional proteins. Without correctly functioning proteins, bacteria cannot maintain cell membrane integrity, regulate vital internal processes, or replicate — leading to rapid and complete bacterial cell death.

This mechanism makes Amikacin bactericidal — actively killing bacteria rather than slowing their growth — a critical distinction in life-threatening infections where rapid and complete bacterial eradication determines survival outcomes. Its chemically modified structure resists most bacterial aminoglycoside-inactivating enzymes — explaining its preserved activity against MDR organisms resistant to Gentamicin and Tobramycin.

At the 250mg dose, Amikacin achieves the high systemic peak concentrations needed for the concentration-dependent killing characteristic of aminoglycosides — where higher peak concentrations relative to the bacterial Minimum Inhibitory Concentration (MIC) produce faster and more complete bacterial eradication. This pharmacodynamic principle is the foundation of once-daily high-dose Amikacin dosing strategies increasingly used in adult patients.

Dosage and Administration

⚠️ Grasil 250mg Injection is strictly a hospital-only medicine. All doses must be individually calculated based on actual body weight and kidney function. Therapeutic drug monitoring is mandatory. Must be prepared and administered exclusively by qualified healthcare professionals.

Administration Guidelines:

• Administer IV doses as a slow infusion over 30 to 60 minutes — never as a rapid IV bolus injection under any circumstances
• For IM administration, inject deep into a large muscle with strict rotation of injection sites between doses
• Therapeutic drug monitoring (TDM) is mandatory — peak blood levels (30 minutes after end of infusion) and trough levels (just before next dose) must be measured and doses individually adjusted
• Assess kidney function before starting with serum creatinine and creatinine clearance — repeat every 2 to 3 days throughout treatment
• Maintain adequate patient hydration throughout the entire course
• Maximum treatment duration: 10 days — prolonged courses are associated with significantly increased risk of permanent hearing damage and irreversible kidney injury

Active Ingredient

Who Should NOT Receive Grasil 250mg 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 life-threatening respiratory failure

Always inform the treating doctor before administration if the patient has:

• Any degree of kidney impairment — mandatory dose reduction and extended intervals; at the 250mg dose, accumulation in kidney disease is a serious and immediate risk
• Pre-existing hearing loss or tinnitus — substantially increases ototoxicity risk at higher doses
• Dehydration or reduced blood volume — must be corrected before starting; dehydration concentrates Amikacin in kidney and cochlear tissue increasing toxicity risk markedly
• Neuromuscular disorders — increased risk of dangerous neuromuscular blockade
• Is pregnant — Amikacin crosses the placenta and causes permanent congenital deafness; use only when a life-threatening infection leaves no safer alternative
• Is elderly — age-related kidney decline substantially increases both nephrotoxicity and ototoxicity risk at this higher dose

Side Effects

At the 250mg dose, Amikacin's narrow therapeutic window makes close monitoring more critical than at lower strengths. The two primary and most serious risks — irreversible hearing loss and kidney damage — are dose-dependent and accumulate with ongoing exposure.

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 causing direct cellular damage — presenting as rising serum creatinine, reduced urination, and electrolyte disturbances. At the 250mg dose, the risk is higher than with lower-strength vials. Kidney function tests are mandatory before starting and every 2 to 3 days throughout treatment. When detected early and treatment modified promptly, nephrotoxicity is usually reversible — but can progress to acute kidney failure if monitoring is delayed.

🔴 Ototoxicity (Permanent Hearing and Balance Damage) — Amikacin concentrates in cochlear fluid (کان کا اندرونی حصہ) and irreversibly destroys inner ear hair cells — causing permanent high-frequency hearing loss (بہرا پن) that often only becomes apparent after treatment ends. Vestibular damage causing lasting dizziness and balance problems can also occur. This hearing damage is permanent — no treatment can restore lost hearing. At 250mg, this risk is substantially higher than at lower doses. Any tinnitus, muffled hearing, or new dizziness must be reported to the medical team immediately without waiting.

Other Serious Side Effects:

• Neuromuscular blockade — rare but potentially fatal respiratory paralysis in patients with neuromuscular disorders or those receiving anaesthetic agents
• Severe allergic reaction — sudden widespread rash, facial or throat swelling, difficulty breathing — emergency intervention required (یہ طبی ہنگامی صورتحال ہے)
• Electrolyte disturbances — low potassium, magnesium, or calcium from kidney tubule damage requiring close monitoring and active replacement

Drug Interactions

Storage Instructions

• Store below 25°C in a cool, dry place protected from direct light
• Do not freeze — freezing alters solution concentration and integrity
• Keep in original packaging until immediately before use
• Keep out of reach of children (بچوں کی پہنچ سے دور رکھیں)
• Inspect vial before every use — solution must be clear and colourless to pale yellow; discard immediately if discoloured or particles are visible
• Use immediately once opened — never store a partially used vial for subsequent doses
• Do not use after the expiry date on the vial label or outer carton

Frequently Asked Questions

Why is Grasil 250mg the most commonly used Amikacin strength in adult hospital settings?

For most adult patients, the required weight-based Amikacin dose — typically 15mg/kg for once-daily dosing or 7.5mg/kg per dose for twice-daily regimens — results in total amounts that are most conveniently and accurately delivered using 250mg vials. Using lower-strength vials for adult doses would require opening and combining multiple vials per dose, increasing preparation complexity, calculation error risk, and medication waste. The 250mg vial allows most adult doses to be prepared from one or two vials with straightforward, accurate measurement — reducing preparation errors in busy clinical settings.

What is once-daily dosing of Amikacin and is it safer than divided doses?

Once-daily high-dose Amikacin — typically 15 to 20mg/kg given as a single daily infusion — is an evidence-based dosing strategy that exploits the pharmacodynamic properties of aminoglycosides. Amikacin kills bacteria in a concentration-dependent manner — meaning a single high peak concentration kills bacteria more effectively than the same total dose spread across multiple smaller doses. Additionally, aminoglycosides exhibit a post-antibiotic effect — bacteria remain suppressed for several hours after drug levels fall below the MIC. Once-daily dosing achieves higher peak concentrations for better bacterial killing while allowing trough levels to fall lower — giving kidneys and inner ear tissue a daily recovery period that may reduce — though not eliminate — toxicity risk compared to multiple daily doses.

How urgently should tinnitus or hearing changes be reported during Grasil 250mg treatment?

Immediately — without waiting for the next scheduled review or blood test. Tinnitus (ringing, buzzing, or hissing in the ears) and perception of muffled or reduced sounds are early warning signs that Amikacin is beginning to accumulate in cochlear tissue at damaging concentrations. At 250mg doses, this accumulation can progress quickly. The window between early, potentially reversible cochlear stress and permanent irreversible hair cell destruction can be narrow. Stopping or modifying treatment at the first sign of auditory change gives the best — and sometimes only — chance of limiting the extent of permanent hearing damage. Reporting these symptoms the same day they are noticed is essential.

Why must Grasil 250mg never be mixed with Piperacillin or Ampicillin in the same IV bag?

Amikacin and beta-lactam antibiotics such as Piperacillin and Ampicillin are chemically incompatible in solution. When mixed together — even briefly — the positively charged aminoglycoside molecules and negatively charged beta-lactam molecules form an insoluble complex that inactivates both antibiotics simultaneously. The patient receives neither drug at its intended therapeutic concentration — potentially resulting in treatment failure for a life-threatening infection. Both medicines must be administered through separate IV lines, or the shared line must be thoroughly flushed with 0.9% Sodium Chloride between infusions. This incompatibility applies even when the antibiotics are prescribed together as an intentional combination therapy — separate administration is always mandatory.

How is Grasil 250mg dose adjusted in patients with kidney impairment?

Because Amikacin is eliminated entirely through the kidneys without any liver metabolism, kidney impairment directly causes Amikacin to accumulate in the body — increasing exposure of the kidneys and inner ear to toxic concentrations with each successive dose. Dose adjustment follows one of two approaches: either reducing the amount of each individual dose while maintaining the standard interval, or maintaining the standard dose but significantly extending the time between doses. The choice and extent of adjustment is calculated using the patient's creatinine clearance measurement. Whichever approach is used, therapeutic drug monitoring becomes even more critical in kidney-impaired patients — with more frequent peak and trough measurements to verify that adjusted doses are achieving therapeutic but not toxic blood levels.

Can Grasil 250mg be used in elderly patients with serious infections?

Yes — when a serious infection confirmed or strongly suspected to involve Amikacin-susceptible organisms leaves no safer antibiotic alternative, Grasil 250mg can be used in elderly patients. However, elderly patients require substantially more careful management than younger adults at this dose. Age-related reduction in kidney function — which often exists even when serum creatinine appears near-normal due to reduced muscle mass in older patients — means Amikacin clears more slowly, accumulating to higher-than-expected levels. Creatinine clearance must be calculated using an age-adjusted formula before starting. Doses should typically be reduced and intervals extended, TDM performed more frequently, kidney function tested daily, and any hearing or balance changes investigated immediately.

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⚕️ Medical Disclaimer: This product description is provided for general informational purposes only and does not replace professional medical advice, diagnosis, or treatment. Grasil 250mg Injection is a prescription-only hospital medicine requiring mandatory therapeutic drug monitoring and continuous kidney 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.

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DRAP Registered | Prescription Required (Rx) | Hospital use only — mandatory kidney function and drug level monitoring — report any hearing changes or reduced urination immediately — maximum 10 days treatment