Pentazocine

INTRODUCTION

Indications

Moderate-to-severe pain. Also used for Analgesia during labor, Sedation prior to surgery; Supplementation in balanced anesthesia.

Action

Binds to opiate receptors in the CNS. Alters perception of and response to painful stimuli, while producing generalized CNS depression. Has partial antagonist properties, which may result in opioid withdrawal in physically dependent patients. Therapeutic Effects: Decrease in moderate to severe pain.

Adverse Reactions/Side Effects

CNS: dizziness, euphoria, hallucinations, headache, sedation, confusion, dysphoria, floating feeling, unusual dreams. EENT: blurred vision, diplopia, miosis (high doses). Resp: respiratory depression. CV: hypertension, hypotension, palpitations. GI: nausea, constipation, dry mouth, ileus, vomiting. GU: urinary retention. Derm: clammy feeling, sweating. Local: severe tissue damage at subcut sites. Misc: physical dependence, psychologic dependence, tolerance.

PHYSICAL THERAPY IMPLICATIONS

Examination and Evaluation

• Assess symptoms of respiratory depression, including decreased respiratory rate, confusion, bluish color of the skin and mucous membranes (cyanosis), and difficult, labored breathing (dyspnea). Monitor pulse oximetry and perform pulmonary function tests (See Appendix I) to quantify suspected changes in ventilation and respiratory function. Excessive respiratory depression requires emergency care.

• Be alert for excessive sedation or changes in mood and behavior (euphoria, dysphoria, confusion, hallucinations). Notify physician or nurse immediately if patient is unconscious or extremely difficult to arouse.

• 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).

• Assess dizziness and drowsiness 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 injection site for pain, swelling, and irritation. Report prolonged or excessive injection-site reactions to the physician.

Interventions

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

• Because of the risk of abnormal BP responses, use caution during aerobic exercise and other forms of therapeutic exercise. Assess exercise tolerance frequently (BP, heart rate, fatigue levels), and terminate exercise immediately if any untoward responses occur (see Appendix L).

• 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, or blurred ...