Nilfene (Fentanyl Citrate)

• Nilfene (fentanyl citrate) is used in the management of severe pain conditions where rapid opioid analgesia is required.
• Severe acute pain: provides rapid, potent analgesia for postoperative, trauma or burn pain.
• Breakthrough cancer pain: delivers fast relief of episodic pain spikes in patients receiving opioid maintenance therapy.
• Adjunct to general anesthesia: enhances intra‑operative analgesia and reduces anesthetic requirements during surgical procedures.

• Fentanyl citrate exerts its effect by binding as a high‑affinity agonist to the μ‑opioid receptors located in the central nervous system. Activation of these G‑protein‑coupled receptors inhibits adenylate cyclase activity, reduces calcium influx and increases potassium efflux, leading to decreased neuronal excitability and suppression of pain signal transmission. Its rapid onset is due to high lipid solubility allowing swift crossing of the blood‑brain barrier.

Fentanyl citrate may be associated with a range of adverse reactions, varying from mild to life‑threatening.

Common Side Effects

• Nausea
• Vomiting
• Constipation
• Dizziness
• Sedation
• Respiratory depression (common)

Serious or Rare Side Effects

• Severe respiratory depression
• Hypotension
• Chest wall rigidity
• Anaphylaxis
• Adrenal insufficiency
• Opioid dependence

• When using Nilfene, careful clinical assessment and monitoring are essential to minimize risks.
• Respiratory monitoring: continuously assess breathing rate and oxygen saturation, especially during initiation and dose adjustments.
• Opioid tolerance assessment: evaluate patient’s prior opioid exposure to determine appropriate starting dose.
• Elderly patients: use lower initial doses and monitor for heightened sensitivity.
• Concomitant CNS depressants: avoid or use with caution when combined with benzodiazepines, barbiturates, or alcohol.
• Hepatic impairment: consider dose reduction and close observation in patients with liver dysfunction.
• Store at 2-8°C: keep refrigerated, protect from light, do not freeze or shake.

Fentanyl citrate can interact with other medicines, altering its analgesic effect or increasing the risk of adverse events.

Major Interactions (Avoid)

• Other opioids: additive respiratory depression and sedation.
• Benzodiazepines or other CNS depressants: profound sedation and respiratory compromise.
• Potent CYP3A4 inhibitors (e.g., ketoconazole, erythromycin): increased fentanyl plasma levels.

Moderate Interactions (Monitor Closely)

• CYP3A4 inducers (e.g., rifampin, carbamazepine): reduced fentanyl efficacy.
• Alcohol: may increase central nervous system depression.