Ziconotide

PRIALT (ziconotide) solution, intrathecal infusion is indicated for the management of severe chronic pain in adult patients for whom intrathecal therapy is warranted, and who are intolerant of or refractory to other treatment, such as systemic analgesics, adjunctive therapies, or intrathecal morphine. PRIALT (ziconotide) solution, intrathecal infusion is an N-type calcium channel antagonist indicated for the management of severe chronic pain in patients for whom intrathecal therapy is warranted, and who are intolerant of or refractory to other treatment, such as systemic analgesics, adjunctive therapies, or intrathecal morphine.

Ziconotide binds to N-type calcium channels located on the primary nociceptive (A-δ and C) afferent nerves in the superficial layers (Rexed laminae I and II) of the dorsal horn in the spinal cord. Although the mechanism of action of ziconotide has not been established in humans, results in animals suggest that its binding blocks N-type calcium channels, which leads to a blockade of excitatory neurotransmitter release from the primary afferent nerve terminals and antinociception.

PRIALT is a non-opioid and non-NSAID analgesic agent used for the management of severe and chronic pain. Administer PRIALT intrathecally by or under the direction of a physician experienced in the technique of intrathecal administration and who is familiar with the drug and device labeling. PRIALT is not for intravenous administration. PRIALT is delivered using a programmable implanted variable-rate microinfusion device or an external microinfusion device and catheter. PRIALT 25 mcg/mL is used undiluted. The 100 mcg/mL formulation must be used diluted until an appropriate dose has been established. Saline solutions containing preservatives must not be used. Refrigerate but do not freeze all PRIALT solutions after preparation. Begin infusion within 24 hours. Initiate PRIALT at no more than 2.4 mcg/day (0.1 mcg/hr) and titrated to patient response.

PRIALT is contraindicated in patients with a known hypersensitivity to ziconotide or any of its formulation components. PRIALT is contraindicated in patients with any other concomitant treatment or medical condition that would render intrathecal administration hazardous. Contraindications to the use of intrathecal analgesia include the presence of infection at the microinfusion injection site, uncontrolled bleeding diathesis, and spinal canal obstruction that impairs circulation of CSF. PRIALT is contraindicated in patients with a pre-existing history of psychosis.

Boxed warning (neuropsychiatric adverse reactions prialt): is contraindicated in patients with a preexisting history of psychosis. Severe psychiatric symptoms and neurological impairment may occur during treatment with PRIALT. Monitor all patients frequently for evidence of cognitive impairment, hallucinations, or changes in mood or consciousness. Discontinue PRIALT therapy in the event of serious neurological or psychiatric signs or symptoms. Cognitive and neuropsychiatric adverse reactions – Cognitive impairment and severe neuropsychiatric symptoms may occur with PRIALT use. Meningitis and other infections – Patients, caregivers, and healthcare providers must be aware of the signs and symptoms of meningitis, including but not limited to fever, headache, stiff neck, altered mental status (e.g., lethargy, confusion, disorientation), nausea or vomiting, and occasionally seizures.

The most frequently reported adverse reactions (≥ 25%) in clinical trials were dizziness, nausea, confusional state, nystagmus.

Formal PK drug-drug interaction studies have not been performed with PRIALT. As ziconotide is a peptide, it is expected to be completely degraded by endopeptidases and exopeptidases (Phase I hydrolytic enzymes) widely located throughout the body, and not by other Phase I biotransformation processes (including the cytochrome P450 system) or by Phase II conjugation reactions. Thus, intrathecal administration, low plasma ziconotide concentrations, and metabolism by ubiquitous peptidases make metabolic interactions of other drugs with ziconotide unlikely. Further, as ziconotide is not highly bound in plasma (approximately 50%) and has low plasma exposure following intrathecal administration, clinically relevant plasma protein displacement reactions involving ziconotide and co-administered medications are unlikely.

Store PRIALT at 2°C to 8°C (36°F to 46°F). Do NOT freeze PRIALT. PRIALT, once diluted aseptically with saline, may be stored at 2°C to 8°C for 24 hours. Protect from light.