Nefalgic (Nefopam Hydrochloride)

Nefopam, a non‑opioid central acting analgesic, is employed in the treatment of moderate pain conditions, particularly after surgery.

• Moderate acute pain: provides effective analgesia without opioid‑related side effects.
• Post‑operative pain: reduces the need for additional opioid rescue medication following surgical procedures.
• Procedural pain: helps control discomfort during minor surgical or diagnostic interventions.

• Nefopam inhibits the reuptake of serotonin, norepinephrine, and dopamine, while also blocking sodium channels and modulating NMDA receptors. This multimodal action reduces neuronal excitability and pain signal transmission in the central nervous system, resulting in analgesic effects without engaging opioid pathways.

Nefopam may cause a range of adverse reactions, most of which are mild and transient.

Common Side Effects

• Nausea: mild to moderate gastrointestinal upset.
• Dry mouth: reduced salivation leading to throat discomfort.
• Sweating: increased perspiration, especially during the first doses.
• Dizziness: transient light‑headedness or vertigo.
• Tachycardia: elevated heart rate without significant hemodynamic compromise.
• Constipation: reduced bowel motility in some patients.

Serious or Rare Side Effects

• Seizures: rare occurrence, particularly in patients with a seizure history.
• Severe hypotension: marked drop in blood pressure requiring medical attention.
• Anaphylactic reaction: acute allergic response with rash, bronchospasm, or angioedema.
• Agranulocytosis: very rare hematologic abnormality with risk of infection.

When prescribing Nefopam, clinicians should consider several safety aspects.

• Renal impairment: monitor renal function and adjust therapy if needed.
• Hepatic impairment: use cautiously and observe liver enzyme levels.
• Cardiovascular disease: watch for tachycardia or arrhythmias during treatment.
• Seizure disorder: avoid or use with heightened vigilance due to seizure risk.
• Concomitant MAO inhibitors: contraindicated because of potential hypertensive crisis.
• Store at room temperature: keep in the original container, protect from moisture and light.

Nefopam can interact with several drug classes, requiring attention to avoid adverse outcomes.

Major Interactions (Avoid)

• MAO inhibitors: may precipitate hypertensive crisis.
• SSRIs or SNRIs: increased risk of serotonin syndrome.
• Anticholinergic agents: additive anticholinergic burden leading to severe dryness and urinary retention.

Moderate Interactions (Monitor Closely)

• Beta‑blockers: may mask tachycardia induced by Nefopam.
• Diuretics: potential electrolyte disturbances when combined.
• General anesthetics: additive central nervous system effects requiring dose adjustment.