Kaptic (Fentanyl Citrate)

• Kaptic, an opioid analgesic, is indicated for conditions involving intense nociceptive pain.
• Severe chronic non‑cancer pain: provides sustained relief when other analgesics are insufficient.
• Breakthrough cancer pain: delivers rapid analgesia for episodic pain spikes in oncology patients.
• Severe acute pain in controlled settings: used under strict medical supervision for intense short‑term pain.

• Fentanyl citrate acts as a high‑affinity agonist at the mu‑opioid receptors in the central nervous system. Binding to these receptors inhibits adenylate cyclase activity, reduces calcium influx, and increases potassium efflux, leading to decreased neuronal excitability and diminished transmission of pain signals.

Fentanyl citrate may cause a range of adverse reactions, from mild to life‑threatening.

Common Side Effects

• Nausea and vomiting
• Constipation
• Drowsiness or sedation
• Dizziness or light‑headedness
• Dry mouth
• Sweating or flushing

Serious or Rare Side Effects

• Respiratory depression or arrest
• Severe hypotension or cardiovascular collapse
• Anaphylactic or hypersensitivity reactions
• Adrenal insufficiency
• Seizures
• Severe confusion or delirium

• When prescribing Kaptic, clinicians should observe several safety measures.
• Assess pain severity and opioid tolerance: confirm that the patient requires a strong opioid.
• Evaluate respiratory function: monitor for depression, especially during initiation.
• Avoid concomitant CNS depressants: limit use with benzodiazepines or alcohol.
• Use the lowest effective dose: titrate carefully to balance analgesia and safety.
• Store at ambient temperature: keep in the original packaging, protect from moisture and light.

Fentanyl citrate interacts with several drug classes that can alter its safety profile.

Major Interactions (Avoid)

• Other opioids or strong analgesics: risk of additive respiratory depression.
• CNS depressants (benzodiazepines, alcohol): profound sedation and respiratory compromise.
• MAO inhibitors: potential for severe hypertension or serotonin syndrome.
• Potent CYP3A4 inhibitors (ketoconazole, erythromycin): increased fentanyl plasma levels.
• Respiratory depressants (muscle relaxants, barbiturates): heightened risk of respiratory failure.

Moderate Interactions (Monitor Closely)

• CYP3A4 inducers (rifampin, carbamazepine): may reduce efficacy.
• Serotonergic agents (SSRIs, SNRIs): monitor for serotonin syndrome.
• Antihistamines and antihypertensives: may enhance sedative effects.
• Diuretics: watch for electrolyte disturbances that could affect cardiac stability.