Are there any risks for ventricular arrhythmias associated with the use of methylphenidate (Ritalin

Fråga: Are there any risks for ventricular arrhythmias associated with the use of methylphenidate (Ritalina)?

The questioner considers treating a 10-year-old boy with Down´s syndrome with methylphenidate due to hyperactivity. The patient has an enlargement of the right ventricle and a pulmonary valve insufficiency. Are there any risks for ventricular arrhythmias associated with the use of methylphenidate?

Sammanfattning: Amphetamine and amphetamine-like agents have sympatomimetic properties and may cause increases in blood pressure and heart rate. Arrhythmias have rarely been described. Intravenous administration appears to increase this risk. If the patient has no history of arrhythmias, and the dose is kept at a level that does not increase the blood pressure, the risk of ventricular arrhythmias is probably very small. Concomitant medication with other agents that could induce arrhythmias should be avoided. If blood pressure increases during methylphenidate treatment, the dose should be reduced.

Svar: Methylphenidate is structurally related to amphetamine and its pharmacological properties are essentially the same. Amphetamine given orally increases systolic and diastolic blood pressure. Heart rate is often reflexly slowed. With large doses, arrhythmias may occur (1). Methylphenidate is contraindicated in patients with angina pectoris and cardiac arrhythmias (2).

There is a case-report of a 13-year-old girl taking 50 mg/day of sertraline who was diagnosed with her first episode of atrioventricular re-entrant tachycardia five days after beginning treatment with an amphetamine product, Adderall. She also experienced chest pain and shortness of breath during treatment with methylphenidate slow release, no arrhythmias were captured. However, before using Adderall, she had used methylphenidate and sertraline for six months without any cardiac symptoms (3).

There is one report describing intravenous administration of methylphenidate 0.15-0.30 mg/kg bodyweight to eight persons with no history of cardiac disease. In two subjects, unifocal. premature ventricular contractions were observed during/within one hour after the infusions (4). In these subjects, the blood pressure also increased.

Another report describes the successful use of methylphenidate against depression in four patients who had developed cardiovascular complications after cardiac surgery that contraindicated the use of tricyclic antidepressants. Methylphenidate was given for one-two weeks at a dose of 10 mg bid without any adverse effects (5).