The CHAMP-study: The CHemopreventive Effect of Lithium in Familial AdenoMatous Polyposis

Patients will be administered lithiumcarbonate by an oral tablet of 300mg once a day for a duration of 6 months. Starting dose is 200mg for the first 5 days, dosage will be then increased to 300mg. To limit adverse events and side-effects, the lowest effective dose will be administered. The target serum level of lithium is 0.20 - 0.40 mmol/L and this will be maintained by regular lithium level testing.