Therapeutic: antiarrhythmics (class IA)
Pharmacologic: membrane stabilizers
Restoration and maintenance of sinus rhythm in patients with atrial fibrillation or flutter. Prevention of recurrent ventricular arrhythmias. Treatment of malaria.
Decrease myocardial excitability. Slow conduction velocity. Therapeutic Effects: Suppression of arrhythmias.
Adverse Reactions/Side Effects
CNS: dizziness, confusion, fatigue, headache, syncope, vertigo. EENT: blurred vision, diplopia, mydriasis, photophobia, tinnitus. CV: HYPOTENSION, TORSADES DE POINTES, arrhythmias, palpitations, tachycardia. GI: anorexia, abdominal cramping, diarrhea, nausea, vomiting, drug-induced hepatitis. Derm: rash. Hemat: AGRANULOCYTOSIS, hemolytic anemia, thrombocytopenia. Neuro: ataxia, tremor. Misc: fever.
PHYSICAL THERAPY IMPLICATIONS
Examination and Evaluation
Assess heart rate, ECG, and heart sounds, especially during exercise (See Appendices G, H). Although intended to treat certain arrhythmias, this drug can unmask or precipitate new arrhythmias (proarrhythmic effect). Report any rhythm disturbances or symptoms of increased arrhythmias, including palpitations, chest pain, shortness of breath, fainting, and fatigue/weakness.
Assess blood pressure periodically and compare to normal values (See Appendix F). Report low blood pressure (hypotension), especially if patient experiences dizziness or syncope.
Monitor signs of blood dyscrasias including agranulocytosis (fever, sore throat, mucosal lesions, other signs of infection), thrombocytopenia (bruising, nose bleeds, bleeding gums), or hemolytic anemia (unusual fatigue, shortness of breath, dizziness, headache, coldness in your hands and feet, pale skin, chest pain). Report these signs to the physician immediately.
Assess dizziness or ataxia 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.
Because of the risk of serious cardiac arrhythmias, use extreme caution during aerobic exercise and other forms of therapeutic exercise. Assess exercise tolerance frequently (blood pressure, heart rate, fatigue levels), and terminate exercise immediately if any untoward responses occur (See Appendix L).
Advise patient and family/caregivers about the signs of cardiac arrhythmias (see above under Examination and Evaluation), and to seek immediate medical assistance if these signs develop.
Advise patient about the likelihood of GI reactions such as nausea, vomiting, diarrhea, and loss of appetite. Instruct patient to report severe or prolonged GI problems, or signs of drug-induced hepatitis (yellow skin or eyes, abdominal pain, severe nausea and vomiting, fever, sore throat, malaise, weakness, facial edema).
Instruct patient and family/caregivers to report other side effects such as severe or prolonged headache, confusion, vision problems, ringing/buzzing in the ears (tinnitus), tremor, fatigue, fever, or skin rash.
Absorption: Bioavailability of oral formulations is 70–80%. Extended-release preparations are absorbed slowly following oral administration.