Riluzole

INTRODUCTION

Indications

Treatment of patients with amyotrophic lateral sclerosis (ALS).

Action

Action may be related to inhibition of glutamate release, inactivation of sodium channels, or interference with neurotransmitter binding at receptor sites. Therapeutic Effects: Extended survival or time to tracheostomy in ALS patients.

Adverse Reactions/Side Effects

CNS: dizziness, weakness, headache. Resp: decreased lung function. CV: hypertension, peripheral edema. GI: abdominal pain, anorexia, diarrhea, dyspepsia, flatulence, nausea, vomiting. Metab: weight loss. MS: arthralgia, back pain. Neuro: circumoral paresthesia.

PHYSICAL THERAPY IMPLICATIONS

Examination and Evaluation

• Assess breathing and notify physician or nursing staff if patient exhibits signs of decreased lung function (dyspnea, shortness of breath, cyanosis). Monitor pulse oximetry and perform pulmonary function tests (See Appendices I, J, K) to quantify suspected changes in ventilation and respiratory function.

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

• 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 any back pain or 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.

• Be alert for dizziness or weakness that might affect transfers or other functional activities. Report balance problems to the physician and nursing staff, and caution the patient and family/caregivers to guard against falls and trauma.

Interventions

• Implement therapeutic exercises (range of motion, resistive training, aerobic activities, respiratory muscle training) as tolerated to compliment the effects of drug therapy and help maintain pulmonary and musculoskeletal function.

Patient/Client-Related Instruction

• Instruct patient and family/caregivers to report other troublesome side effects, including severe or prolonged headache, numbness around the mouth, or GI problems (nausea, vomiting, diarrhea, indigestion, loss of appetite, flatulence, abdominal pain).

Pharmacokinetics

Absorption: Well absorbed (90%) after oral administration, but bioavailability is 50%.

Distribution: Readily penetrates brain.

Protein Binding: 96%.

Metabolism and Excretion: Highly metabolized by the liver (some metabolites are pharmacologically active); 2% excreted unchanged in urine.

Half-life: 12 hr (after multiple doses).

Contraindications/Precautions

Contraindicated in: Severe hypersensitivity.

Use Cautiously in: Hepatic or renal ...