Most commonly giddiness, dizziness and light-headedness. Visual disturbance, such as double vision and blurring of vision, may occur. More rarely nausea and vomiting have been reported. These effects are usually transient and disappear upon continuing or reducing the dosage. Pro-arrhythmic effects occur but are most likely in patients with structural heart disease and/or significant left ventricular impairment. A number of cases of elevated liver enzymes and jaundice have been reported in association with Tambocor. So far this has always been reversible on stopping treatment.