fentanyl citrate: clinical use

Prescribing considerations

• Confirm the licensed indication and opioid tolerance before prescribing Abstral or PecFent; neither is intended for opioid-naive patients or general acute pain.
• Do not assume rapid-acting fentanyl products are directly interchangeable; absorption and exposure differ between formulations.
• Assess respiratory disease, sleep-related breathing disorders, cardiovascular status, hepatic or renal impairment, frailty and risk factors for opioid misuse.
• Document treatment goals, safe storage, overdose recognition and an eventual withdrawal strategy.
• Injectable fentanyl requires trained staff, airway-control capability, resuscitation equipment and an opioid antagonist immediately available.

Contraindications and cautions

• Hypersensitivity to fentanyl or relevant excipients.
• Abstral and PecFent: absence of established maintenance opioid therapy, severe respiratory depression or severe obstructive lung disease, acute pain other than breakthrough pain, and concurrent sodium oxybate.
• Selected injectable products: respiratory depression, obstructive airways disease and concurrent or recent MAO-inhibitor treatment. Contraindications differ between formulations, so check the exact product information.

Monitoring

• Respiratory rate, oxygenation, consciousness and sedation.
• Blood pressure and heart rate, including bradycardia.
• Analgesic response and signs of opioid-induced hyperalgesia.
• Constipation, nausea and other opioid adverse effects.
• Tolerance, dependence, withdrawal, misuse or opioid use disorder.
• Serotonin-syndrome features when serotonergic medicines are present.
• Signs of accumulation or prolonged toxicity in older, frail, hepatically impaired or renally impaired patients.

Clinical pharmacology

Fentanyl is a highly lipophilic mu-opioid receptor agonist. It is rapidly distributed, primarily metabolised by CYP3A4 to inactive metabolites and eliminated mainly in urine as metabolites; impaired clearance or CYP3A4 inhibition can prolong opioid effects.

Formulation and product differences

• Injection is administered intravenously or intramuscularly in monitored clinical settings and is licensed for perioperative analgesia and severe pain.
• Abstral is a rapidly dissolving sublingual formulation for breakthrough cancer pain in opioid-tolerant adults.
• PecFent is an intranasal formulation that forms a gel in the nose; delivery is confirmed by its click and counter.
• Rapid-acting fentanyl products have important absorption differences and should not be treated as equivalent when switching.

Nasal preparation

Route: Nasal

Strengths: 100 micrograms, 400 micrograms

Injection

Route: Parenteral

Strengths: 50 micrograms/mL

Sublingual tablet

Route: Sublingual

Strengths: 100 micrograms, 200 micrograms, 300 micrograms, 400 micrograms, 600 micrograms, 800 micrograms