Rectal Suppository is NOT an Available Dosage Form of Fentanyl
Rectal suppository is not a commercially available or FDA-approved dosage form of fentanyl. While the other three options—buccal film, intravenous injection, and iontophoretic transdermal system—are all established formulations, fentanyl has never been developed or approved as a rectal suppository.
Available Fentanyl Formulations
Buccal Film (Available)
- Buccal formulations are FDA-approved for breakthrough cancer pain in opioid-tolerant patients, providing rapid onset of analgesia within 10-15 minutes 1
- These transmucosal formulations have Grade I, Level A recommendation from the European Society for Medical Oncology for unpredictable and rapid-onset breakthrough cancer pain 1
- Indicated only for patients receiving oral morphine equivalents of at least 60 mg daily 1
Intravenous (Available)
- Intravenous fentanyl is the original and most established formulation, widely used in anesthesia and acute pain management 2
- Onset of action after IV administration is 1-2 minutes with duration of 30-60 minutes 1
- Approximately 80 times more potent than parenteral morphine 2, 1
- Extensively recommended across all levels of care (basic, intermediate, and advanced) for postoperative pain management 2
Iontophoretic Transdermal (Available)
- Patient-controlled iontophoretic transdermal system was developed specifically for on-demand delivery of transdermal bolus doses to treat postoperative pain 3
- Offers a needle-free system to provide patient-controlled analgesia otherwise offered by intravenous pumps 3
- Note: Due to technical difficulties, this system has had periods of clinical unavailability 3
Why Rectal Suppository Does NOT Exist
Documented Formulations in Literature
- Comprehensive reviews of fentanyl formulations consistently list: transdermal patches, oral transmucosal, intranasal, buccal, sublingual, iontophoretic transdermal, and parenteral routes 4, 5, 3
- Rectal administration is conspicuously absent from all pharmaceutical formulation reviews of fentanyl 4, 5, 3
Pharmacokinetic Rationale
- Fentanyl's high lipophilicity (octanol:water partition coefficient >700) and first-pass metabolism make it suitable for transmucosal and transdermal routes that bypass hepatic metabolism 4
- While rectal administration can bypass some first-pass metabolism, fentanyl has never been commercially developed in this form despite its theoretical feasibility 4
Clinical Practice Evidence
- Pediatric and adult pain management guidelines extensively document rectal administration of NSAIDs, paracetamol, and tramadol, but never mention rectal fentanyl 2
- The only documented non-approved rectal use involves illicit extraction from transdermal patches for abuse purposes, not legitimate pharmaceutical formulations 6
Common Pitfall to Avoid
- Do not confuse the availability of other opioids in rectal suppository form (such as morphine or oxycodone 2) with fentanyl availability—fentanyl has never been marketed as a rectal suppository despite other opioids having this formulation