Botulinum Toxin (Type A)

INTRODUCTION

Indications

Temporary improvement in the appearance of moderate-to-severe glabellar lines (brow furrow) associated with corrugator and/or procerus muscle activity in adults ≤65 yr. Unlabeled Use: Treatment of spasticity in specific muscle groups.

Action

Produces partial chemical denervation by inhibiting the release of acetylcholine. Result is local decrease in muscle activity. Therapeutic Effects: Decreased brow furrow with improved appearance. Decreased muscle spasticity.

Adverse Reactions/Side Effects

CNS: headache. EENT: temporary eyelid droop. GI: nausea. Local: discomfort at injection sites. MS: local muscle weakness. Misc: ALLERGIC REACTIONS, INCLUDING ANAPHYLAXIS (RARE).

PHYSICAL THERAPY IMPLICATIONS*

^*When injected intramuscularly to treat spasticity

Examination and Evaluation

• Monitor signs of allergic reactions and anaphylaxis, including pulmonary symptoms (laryngeal edema, wheezing, cough, dyspnea) or skin reactions (rash, pruritus, urticaria). Notify physician immediately if these reactions occur.

• Be alert for possible systemic effects that might occur if botulinum toxin spreads beyond the IM injection site. Systemic effects include difficulty swallowing (dysphagia), difficulty speaking (dysphonia), and respiratory distress (dyspnea, decreased pulse oximetry values, cyanosis). Report signs of systemic botulism to the physician immediately. Excessive respiratory depression requires emergency care.

• Assess spasticity, ROM, and functional ability as the drug begins to take effect. Document whether changes in spasticity and tone are consistent with rehabilitation goals.

• Monitor IM injection site for redness and irritation. Report prolonged or excessive skin reactions to the physician.

Interventions

• Implement aggressive therapeutic exercises (neuromuscular reeducation, postural stabilization, gait training, other task-specific training) to facilitate voluntary motor function and help patient adjust to reduced spasticity and tone.

• Provide appropriate assistive devices (walker, cane, crutches) while patient adjusts to reduced levels of spasticity. Specifically, make sure patient can ambulate and transfer safely while adjusting to reduced tone in the lower extremities.

• When indicated, incorporate serial casting and similar techniques to capitalize on drug effects and achieve maximal soft tissue lengthening and help reduce contractures.

Patient/Client-Related Instruction

• Explain to patient and family/caregivers that results typically last 2–3 months. Periodic reinjection may be needed to sustain antispasticity effects.

• Instruct patient or family/caregivers to report severe or prolonged headache, nausea, or other untoward responses.

Pharmacokinetics

Absorption: Minimal systemic absorption; action is primarily local.

Distribution: Unknown.

Metabolism and Excretion: Unknown.

Half-life: Unknown.

Contraindications/Precautions

Contraindicated in: Hypersensitivity; Presence of infection ...