On theoretical grounds, overdosage would be expected to cause enhancement of the pharmacological side effects mentioned in Adverse Reactions. Observations in animals show that extreme overdosage (100-200 times the recommended daily dose) may produce oestrogenic effects.
There have been reports in the literature that NOLVADEX given at several times the standard dose may be associated with prolongation of QT interval of the ECG.
There is no specific antidote to overdosage and treatment must be symptomatic.