Naloxone

INTRODUCTION

Indications

Reversal of CNS depression and respiratory depression because of suspected opioid overdose. Unlabeled Use: Opioid-induced pruritus (low dose IV infusion). Management of refractory circulatory shock.

Action

Competitively blocks the effects of opioids, including CNS and respiratory depression, without producing any agonist (opioid-like) effects. Therapeutic Effects: Reversal of signs of opioid excess.

Adverse Reactions/Side Effects

CV: hypertension, hypotension, ventricular fibrillation, ventricular tachycardia. GI: nausea, vomiting.

PHYSICAL THERAPY IMPLICATIONS

Examination and Evaluation

• Report any remaining signs of opioid-induced CNS depression such as euphoria, dysphoria, confusion, and hallucinations.

• Be alert for any residual symptoms of respiratory depression, including decreased respiratory rate, confusion, bluish color of the skin and mucous membranes, and difficult/labored breathing. Monitor pulse oximetry and perform pulmonary function tests (See Appendix I) to document whether ventilation and respiratory function have returned to normal levels.

• 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 heart rate, ECG, and heart sounds, especially during exercise (See Appendices G, H). Report any rhythm disturbances or symptoms of arrhythmias, including palpitations, chest discomfort, shortness of breath, fainting, and fatigue/weakness.

• If used to treat opioid-induced itching (pruritus), monitor symptoms to help document whether drug therapy is successful in reducing itching.

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

Patient/Client-Related Instruction

• Educate patient about the dangers of opioid overdose; encourage patient to adhere to proper dosing schedule.

• Instruct patient to report other troublesome side effects such as severe or prolonged GI problems (nausea, vomiting).

Pharmacokinetics

Absorption: Well absorbed after IM or SC administration.

Distribution: Rapidly distributed to tissues. Crosses the placenta.

Metabolism and Excretion: Metabolized by the liver.

Half-life: 60–90 min (up to 3 hr in neonates).

Contraindications/Precautions

Contraindicated in: Hypersensitivity.