Gabapentin

INTRODUCTION

Indications

Partial seizures (adjunct treatment). Postherpetic neuralgia. Unlabeled Use: Chronic pain. Prevention of migraine headache. Bipolar disorder. Anxiety.

Action

Mechanism of action is not known. May affect transport of amino acids across and stabilize neuronal membranes. Therapeutic Effects: Decreased incidence of seizures. Decreased postherpetic pain.

Adverse Reactions/Side Effects

CNS: confusion, depression, drowsiness, sedation, anxiety, concentration difficulties (children), dizziness, emotional lability (children), hostility, hyperkinesia (children), malaise, vertigo, weakness. EENT: abnormal vision, nystagmus. CV: hypertension. GI: weight gain, anorexia, flatulence, gingivitis. MS: arthralgia. Neuro: ataxia, altered reflexes, hyperkinesia, paresthesia. Misc: facial edema.

PHYSICAL THERAPY IMPLICATIONS

Examination and Evaluation

• Document the number, duration, and severity of seizures to help determine if this drug is effective in reducing seizure activity.

• Monitor drowsiness, anxiety, confusion, and other changes in mood or behavior (hostility, emotional lability, concentration difficulties). Repeated or excessive symptoms may require change in dose or medication.

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

• If treating neuropathic pain or other pain syndromes (migraine, chronic pain, postherpetic neuralgia), use visual analogue scales and other appropriate pain scales to assess the patient's pain and help document the effects of drug therapy.

• If treating anxiety or bipolar disorder, monitor any changes in the patient's mood or behavior. Report manic symptoms (excitement, agitation) or symptoms of depression (sadness, apathy, loss of energy).

• Assess gait and motor function and document any signs of ataxia, increased motor activity (hyperkinesias), or other abnormal motor symptoms. Report these signs to the physician.

• Assess signs of paresthesia (numbness, tingling) or changes in reflex activity. Perform objective tests, including electroneuromyography and sensory testing to document any drug-related neuropathic changes.

• Assess blood pressure periodically and compare to normal values (See Appendix F). Report a sustained increase in blood pressure (hypertension) to the physician.

• Assess any joint pain to rule out musculoskeletal pathology; that is, try to determine if pain is drug induced rather than caused by anatomic or biomechanical problems.

• Periodically assess body weight and other anthropometric measures (body mass index, body composition). Report a substantial or unexplained weight gain or increase in body fat.

Interventions

• Guard against falls and trauma (hip fractures, head injury, and so forth), especially if gait and balance are affected by drowsiness, dizziness, or ataxia. Implement fall prevention strategies, especially if balance is impaired (See Appendix E).

• If treating neuropathic pain or other pain syndromes, implement appropriate interventions (physical agents, manual techniques, therapeutic exercise) to ...