Primidone

INTRODUCTION

Indications

Management of tonic-clonic, complex partial, and focal seizures. Unlabeled Use: Management of essential (familial) tremor.

Action

↓ neuronal excitability. ↑ the threshold of electric stimulation of the motor cortex. Therapeutic Effects: Prevention of seizures.

Adverse Reactions/Side Effects

CNS: ataxia, drowsiness, vertigo, excitement (increased in children). EENT: visual changes. Resp: dyspnea. CV: edema, orthostatic hypotension. GI: anorexia, drug-induced hepatitis, nausea, vomiting. Derm: alopecia, rash. Hemat: blood dyscrasias, megaloblastic anemia. Misc: folic acid deficiency.

PHYSICAL THERAPY IMPLICATIONS

Examination and Evaluation

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

• Be alert for signs of megaloblastic anemia (unusual fatigue, weakness, dizziness, pallor) or signs of fever, infection, and poor health that might be due to other blood dyscrasias or folic acid deficiency. Report these signs to the physician immediately.

• Assess dizziness and vertigo 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.

• Assess peripheral edema using girth measurements, volume displacement, and measurement of pitting edema (See Appendix N). Report increased swelling in feet and ankles or a sudden increase in body weight due to fluid retention.

• Assess blood pressure (BP) when patient assumes a more upright position (lying to standing, sitting to standing, lying to sitting). Document orthostatic hypotension and contact physician when systolic BP falls >20 mm Hg, or diastolic BP falls >10 mm Hg.

• Monitor daytime drowsiness or excitement. Repeated or excessive symptoms may require change in dose or medication.

Interventions

• Guard against falls and trauma (hip fractures, head injury, and so forth), especially if drowsiness or vertigo affects gait and balance. Implement fall-prevention strategies, especially if balance is impaired (See Appendix E).

• To minimize orthostatic hypotension, patient should move slowly when assuming a more upright position.

Patient/Client-Related Instruction

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

• Advise patients on prolonged antiseizure therapy not to discontinue medication without consulting their physician. Abrupt withdrawal may cause increased seizures.

• Advise patient about the risk of daytime drowsiness and decreased attention and mental focus. Use care if driving or in other activities that require strong concentration and fast responses.

• Advise patient about the likelihood of GI reactions such as nausea, vomiting, and loss of appetite. Instruct patient to report severe or prolonged GI problems or signs of drug-induced hepatitis, including yellow skin or ...