4-aminopyridine, 4-AP, fampridine
Therapeutic: anti–multiple sclerosis agents
Pharmacologic: potassium channel blocker
Treatment of multiple sclerosis (MS); to improve walking speed.
Acts as a potassium channel blocker, which may increase conduction of action potentials. Therapeutic Effects: Increased walking speed in patients with MS.
Adverse Reactions/Side Effects
CNS: SEIZURES, dizziness, headache, insomnia, weakness. EENT: nasopharyngitis, pharyngolaryngeal pain. GI: constipation, dyspepsia, nausea. GU: urinary tract infection. MS: back pain. Neuro: balance disorder, MS relapse, paresthesia.
PHYSICAL THERAPY IMPLICATIONS
Be alert for new seizures or increased seizure activity, especially at the onset of drug treatment. Document the number, duration, and severity of seizures, and report these findings to the physician immediately.
Periodically assess balance, coordination, spasticity, gait, and other aspects of neuromuscular function. Document any improvement in function, but also report worsening of impairments or a relapse of MS symptoms.
Assess any back pain to rule out musculoskeletal pathology; that is, try to determine if pain is drug induced rather than caused by anatomic or biomechanical problems.
Assess signs of paresthesia (numbness, tingling) or muscle weakness. Perform objective tests, including electroneuromyography and sensory testing to document any drug-related neuropathic changes.
Assess dizziness that might affect gait, balance, and other functional activities (See Appendix C). Report balance problems and functional limitations to the physician and nursing staff, and caution the patient and family/caregivers to guard against falls and trauma.
Design and implement coordination, balance, gait training, and other therapeutic exercises to maintain function, and complement drug effects in patients with MS.
Instruct patient to report other troublesome side effects such as prolonged or severe headache, sleep loss, upper respiratory tract irritation, urinary tract infection, or GI problems (nausea, indigestion, constipation).
Absorption: Rapidly and completely absorbed (96%).
Metabolism and Excretion: 96% eliminated in urine, 0.5% in feces
TIME/ACTION PROFILE (improvement in walking speed)
|ROUTE ||ONSET ||PEAK ||DURATION |
|PO ||unknown ||3–4 hr ||24 hr |
Contraindicated in: History of seizures; Moderate/severe renal impairment (↑ risk of seizures); Lactation: Avoid use.
Use Cautiously in: Geri: Consider age-related ↓ in renal function; OB: Use only if potential benefit justifies potential risk to fetus; Pedi: Safety and effectiveness not established.
PO (Adults): 10 mg twice daily.