Ziconotide

INTRODUCTION

Indications

Management of severe chronic pain when conventional therapies (analgesics or other adjunctive measures) have failed.

Action

Blocks spinal N-channel calcium channels, decreasing transmission of pain signals to the brain. Has no effect on opioid receptors. Therapeutic Effects: ↓ in severe pain.

Adverse Reactions/Side Effects

CNS: MENINGITIS, confusion, dizziness, drowsiness, headache, impaired memory, weakness, aphasia, ↓ alertness/responsiveness, cognitive impairment, hallucinations, psychiatric symptoms, speech disorder. CV: changes in blood pressure. EENT: nystagmus, abnormal vision. GI: nausea, anorexia, vomiting. Local: catheter/injection site reactions. MS: hypertonia, urinary retention, ↑ creatine kinase. Neuro: abnormal gait, ataxia. Misc: fever.

PHYSICAL THERAPY IMPLICATIONS

Examination and Evaluation

• Be alert for signs of meningitis, including severe headache, neck stiffness, nausea, vomiting, confusion, drowsiness, sensitivity to light, loss of appetite, high fever, skin rash, and seizures. Notify physician or nurse immediately if patient exhibits these signs.

• Use appropriate pain scales (visual analogue scales, others) to document whether this drug is successful in helping manage the patient's pain.

• Assess blood pressure (BP) and compare to normal values (See Appendix F). Report changes in BP, either a problematic decrease in BP (hypotension) or a sustained increase in BP (hypertension).

• Be alert for changes in mood and behavior, including hallucinations, impaired memory, speech problems, decreased cognition, and other psychiatric symptoms. Report these signs to the physician or nurse.

• Assess patient's gait and motor function periodically, and report any gait abnormalities or increased muscle tone.

• Assess dizziness or ataxia that might affect gait, balance, and other functional activities (See Appendix C). Report balance problems and functional limitations to the physician and nursing staff, and caution the patient and family/caregivers to guard against falls and trauma.

• Monitor intrathecal injection site and catheter placement for pain, swelling, and irritation. Report prolonged or excessive administration site reactions to the physician.

Interventions

• Implement appropriate manual therapy techniques, physical agents, and therapeutic exercises to reduce pain and help wean patient off analgesics as soon as possible.

• Help patient explore other nonpharmacologic methods to reduce chronic pain, such as relaxation techniques, exercise, counseling, and so forth.

• Guard against falls and trauma (hip fractures, head injury). Implement fall-prevention strategies (See Appendix E), especially if patient exhibits sedation, dizziness, ataxia, or blurred vision.

Patient/Client-Related Instruction

• Advise patient that analgesics are usually more effective if given before pain becomes severe; emphasize that adequate pain control will allow better participation in physical therapy.

• Advise patient to avoid alcohol and other CNS depressants because of the increased risk of sedation and decreased ...