Careful Administration (HERBESSER, HERBESSER 60 and HERBESSER R100 should be administered with care in the following patients.): Patients with congestive heart failure. [The symptoms of heart failure may be exacerbated.]
Patients with severe bradycardia (less than 50 beats/minute) or 1st-degree atrioventricular block. [Excessive inhibition of sinus rhythm and cardiac conduction may occur.]
Patients with severe hypotension. [The blood pressure may be further reduced.]
Patients with severe hepatic and renal dysfunction. [The action of the drug may be enhanced due to its delayed metabolism and excretion.]
Important Precautions: It has been reported that abrupt withdrawal of calcium antagonists may result in aggravation of symptoms. If HERBESSER, HERBESSER 60 and HERBESSER R100 are withdrawn, the dosage should be gradually reduced and the patient should be carefully monitored. The patient should be instructed not to discontinue taking the drug without consulting a physician.
Since dizziness, etc. due to hypotensive effect may occur, patients should be cautioned against engaging in potentially hazardous activities requiring alertness, such as driving a car, working at heights, or operating machinery, etc.
It has been reported that concomitant use of other antiarrhythmic agent (disopyramide phosphate with terfenadine may result in QT interval prolongation and ventricular arrhythmia.
Pediatric Use: The safety of HERBESSER and HERBESSER 60 in children has not been established.
Use in the Elderly: An excessive reduction in blood pressure is undesirable in elderly patients. Therapy should therefore be instituted with special care, starting at a reduced dosage with careful monitoring of the patient's condition.