Comparative Pharmacology
Head-to-head clinical analysis: IONSYS versus ZOHYDRO ER.
Peer-Reviewed Evidence
Head-to-head clinical analysis: IONSYS versus ZOHYDRO ER.
IONSYS vs ZOHYDRO ER
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
IONSYS is an iontophoretic delivery system for fentanyl, a mu-opioid receptor agonist. Fentanyl binds to mu-opioid receptors in the CNS, inhibiting ascending pain pathways and altering pain perception and emotional response.
Zohydro ER is a pure opioid agonist with relative selectivity for mu-opioid receptors, although it can interact with other opioid receptors at higher doses. Its primary therapeutic action is analgesia via binding to mu-opioid receptors in the central nervous system, leading to activation of descending inhibitory pathways and modulation of pain perception.
Apply one 40 mcg fentanyl iontophoretic transdermal system to skin on upper arm or chest; delivers 40 mcg per dose on-demand for up to 24 hours or 80 doses, whichever is shorter. Maximum 2 doses per hour, 6 doses per application. Patient must be opioid-tolerant.
Initial: 20 mg orally every 24 hours; titrate in increments of 10-20 mg every 3-7 days as needed; maximum dose 200 mg every 24 hours.
None Documented
None Documented
Terminal elimination half-life: 16.3 ± 9.1 hours for fentanyl released from IONSYS; accounts for prolonged release from depot and is longer than intravenous fentanyl (3-12 hours).
Terminal elimination half-life is approximately 10.6 hours (range 8-17 hours) due to extended-release formulation; immediate-release hydromorphone half-life is 2-3 hours. Clinically, steady-state is achieved after 3-5 days of dosing.
Renal: approximately 90% as fentanyl metabolites (mainly norfentanyl) and less than 10% as unchanged drug; fecal: less than 10%.
Primarily renal excretion of hydromorphone-3-glucuronide (H3G, ~60%), unchanged hydromorphone (~15%), and other conjugates. Fecal excretion accounts for ~25%.
Category C
Category C
Opioid Analgesic
Opioid Analgesic