0.5% w/v METRONIDAZOLE INJECTION, USP [MEDISAL] Injection

What is 0.5% w/v METRONIDAZOLE INJECTION, USP [MEDISAL]

0.5% w/v Metronidazole Injection, USP [MEDISAL] is a sterile, ready-to-use intravenous infusion containing the antimicrobial agent metronidazole. It is primarily used for the treatment and prevention of anaerobic bacterial and protozoal infections. This formulation is particularly suited for patients who cannot take oral medication or require parenteral therapy for severe infections.

• Generic Name: Metronidazole
• Form: Intravenous Infusion
• Strength: 0.5% w/v (i.e., 500 mg in 100 ml)
• Container: 100ml Polypropylene Bottle
• Therapeutic Class: Antibacterial and Antiprotozoal Agent
• ATC Code: J01XD01

This medication is widely used in the management of:

• Intra-abdominal infections (e.g., peritonitis, liver abscess)
• Gynecological infections (e.g., endometritis, pelvic cellulitis)
• Bone and joint infections
• Central nervous system infections (e.g., brain abscess)
• Septicemia caused by anaerobic bacteria
• Post-operative prophylaxis in colorectal surgeries

Due to its excellent anaerobic coverage, metronidazole is often combined with other antimicrobials for synergistic effect against mixed infections.

How to use 0.5% w/v METRONIDAZOLE INJECTION, USP [MEDISAL]

0.5% w/v Metronidazole Injection, USP [MEDISAL] should only be administered under the supervision of healthcare professionals. The intravenous route is appropriate for moderate to severe infections or when oral administration is not feasible.

• Route of Administration: Intravenous infusion
• Infusion Rate: Infuse over 20 to 60 minutes
• Preparation: The solution comes pre-mixed and does not require dilution; inspect for particulate matter before use.
• Aseptic Technique: Ensure sterile technique is used to prevent contamination during administration.

Steps for use:

1. Check the expiry date and ensure the solution is clear and free of particulates.
2. Connect the infusion bottle to the IV set using sterile equipment.
3. Administer slowly via intravenous drip to avoid potential side effects like thrombophlebitis or seizures.
4. Monitor patient for signs of allergic reactions or infusion-related complications.

Always adhere strictly to your physician's dosing schedule, and do not co-administer with incompatible IV drugs in the same line. Flush lines as needed between medications.

Mode of Action 0.5% w/v METRONIDAZOLE INJECTION, USP [MEDISAL]

Metronidazole is a nitroimidazole class antimicrobial agent that exhibits potent bactericidal and protozoal activity under anaerobic conditions.

• Target Organisms: Anaerobic bacteria and protozoa
• Antibacterial Spectrum: Bacteroides spp., Clostridium spp., Fusobacterium spp., and others

Mechanism of Action:

• After passive diffusion into anaerobic cells, metronidazole is reduced by intracellular transport proteins to its active form.
• The reduced form of metronidazole interacts with DNA, leading to strand breakage and inhibition of nucleic acid synthesis.
• This disruption of DNA function is lethal to the target organism, resulting in cell death.

Metronidazole is selectively toxic to anaerobic cells because the drug requires reduction by anaerobic enzymes for activation. Aerobic organisms generally lack these reductive systems and are therefore resistant.

0.5% w/v METRONIDAZOLE INJECTION, USP [MEDISAL] Interactions 0.5% w/v METRONIDAZOLE INJECTION, USP [MEDISAL]

Metronidazole may interact with various medications and substances, leading to altered efficacy or increased toxicity. It is essential to inform healthcare providers about all concurrent medications.

• Alcohol: Should be avoided; may cause a disulfiram-like reaction with symptoms such as nausea, vomiting, flushing, and tachycardia.
• Disulfiram: Concomitant use may lead to acute psychosis and confusion; avoid combining.
• Warfarin and Other Anticoagulants: May enhance anticoagulant effect due to inhibition of warfarin metabolism; monitor INR closely.
• Phenytoin and Phenobarbital: May decrease plasma concentrations of metronidazole by inducing hepatic enzymes.
• Lithium: Risk of lithium toxicity increases; monitor serum lithium levels when used concurrently.
• Cimetidine: May inhibit hepatic metabolism of metronidazole, raising plasma levels and risk of side effects.
• Cyclosporine: Risk of elevated cyclosporine and creatinine levels; monitor carefully.

Patients must disclose herbal supplements and over-the-counter drugs to minimize the risk of adverse interactions.

Dosage of 0.5% w/v METRONIDAZOLE INJECTION, USP [MEDISAL]

The dosage of 0.5% w/v Metronidazole Injection, USP [MEDISAL] varies depending on the type and severity of the infection, age, and renal or hepatic function of the patient.

• Adults: Typically 500 mg every 8 hours intravenously over 20–60 minutes
• Severe Infections: Up to 1.5–2 g/day may be required in divided doses
• Prophylaxis (Pre-Op): 500 mg IV 30–60 minutes before surgery, followed by 500 mg every 8 hours for up to 24 hours
• Children: 7.5 mg/kg every 8 hours (not exceeding adult dose)

Special Considerations:

• Adjust dosage in severe hepatic impairment due to prolonged half-life.
• No significant dose adjustment in renal impairment, but caution in dialysis patients.
• Continue treatment for the full prescribed course to prevent resistance.

Dosing should always be guided by microbial sensitivity, clinical response, and therapeutic drug monitoring when appropriate.

Possible side effects of 0.5% w/v METRONIDAZOLE INJECTION, USP [MEDISAL]

Metronidazole is generally well-tolerated, but like all medications, it may cause side effects ranging from mild to severe. These reactions may require dose adjustments or discontinuation in some cases.

• Common Side Effects:
  • Nausea and vomiting
  • Metallic taste
  • Headache
  • Abdominal discomfort or cramping
  • Loss of appetite
• Less Common Effects:
  • Dark-colored urine (harmless but alarming to some patients)
  • Dizziness or lightheadedness
  • Rash or itching
• Serious Adverse Effects:
  • Seizures or peripheral neuropathy (long-term use)
  • Allergic reactions such as anaphylaxis or angioedema
  • Hepatotoxicity (especially in those with liver disease)
  • Blood dyscrasias (e.g., leukopenia, thrombocytopenia)

Patients are advised to report any unusual neurological symptoms, allergic reactions, or gastrointestinal issues promptly to their healthcare provider.

0.5% w/v METRONIDAZOLE INJECTION, USP [MEDISAL] Contraindications 0.5% w/v METRONIDAZOLE INJECTION, USP [MEDISAL]

Not all patients are suitable candidates for metronidazole therapy. Specific contraindications and cautions should be considered before prescribing.

• Absolute Contraindications:
  • Hypersensitivity to metronidazole, other nitroimidazoles, or any excipients in the formulation
  • First trimester of pregnancy (unless clearly needed)
  • Concurrent use with disulfiram
  • Alcohol consumption during and up to 48 hours after treatment
• Relative Contraindications / Caution Required:
  • Severe hepatic impairment
  • History of blood dyscrasias
  • Neurological disorders, including epilepsy
  • Chronic alcohol use

Risk-benefit evaluation is crucial in vulnerable populations, such as pregnant women (especially in the first trimester) and patients with central nervous system disorders.

Storage of 0.5% w/v METRONIDAZOLE INJECTION, USP [MEDISAL]

Proper storage ensures the efficacy and safety of the medication until its expiration. Careful handling also prevents degradation or contamination of the solution.

• Storage Temperature: Store at 20°C to 25°C (68°F to 77°F)
• Light Sensitivity: Protect from direct light; store in original packaging
• Freezing: Do not freeze; freezing can cause precipitation or damage to the container
• Container: Keep in the polypropylene bottle; inspect for leakage, discoloration, or particulate matter before use

Stability Notes:

• Use immediately after opening
• Once opened, any unused portion must be discarded
• Do not mix with incompatible IV solutions in the same line unless confirmed stable

Adhering to proper storage guidelines is critical to maintain the drug’s potency and sterility.