Therapeutic Lithium Intoxication - An Increasing Problem in Sweden

• Main Authors: Lundholm, B, Landgren, A, Hoejer, J
• Format: Conference Proceeding
• Language: English
• Subjects: Medicin och hälsovetenskap
• ISSN: 1556-3650

Objective: During recent years the Swedish poisons centre has noticed an increase in inquiries concerning therapeutic lithium intoxication. The aim of this study was to investigate the circumstances of these therapeutic misadventures and to find out if this tendency correlated with an increase in the use of lithium. Methods: Information recorded in connection with all hospital calls regarding therapeutic lithium intoxication during the period 2001-2006 was studied retrospectively. Results: During the study period the poisons centre received the following number of inquiries annually concerning patients with therapeutic lithium intoxication 12-13-15-17-28-31 respectively. In total 116 patients. During the same period the amount of lithium sold by Swedish pharmacies increased by 17% only, so additional explanations must be sought. Patients were middle-aged or elderly, females dominated. Concerning the circumstances, a remarkable finding was that many patients stayed at home despite rather pronounced symptoms, which delayed diagnosis and treatment. At least 19 patients (16%) had symptoms for 1-2 weeks, and 12 patients (10%) had symptoms for 3-4 weeks or more before medical care was sought. Initially at least 20% of the cases were observed at a psychiatric clinic, and diagnosis was further delayed. Intake of lithium sometimes continued. In several cases stroke or other diagnosis were suspected. Serum lithium concentrations were available to the study group in 101 cases. 52 cases had 2.0-5.6 mmol/L, 32 had 1.5-1.9 mmol/L and in 17 cases the S-Li was below 1.5 mmol/L. Frequently recorded symptoms were confusion and other changes in mental status, tremor, GI-symptoms, dehydration and impaired renal function. Several patients had deteriorated nutritional status. Coma and bradycardia occurred occasionally. Hemodialysis were recommended by the poisons centre in 22 cases and discussed in another 14. Conclusion: The increasing number of therapeutic lithium intoxications could not be explained only by a certain increase in the use of the drug. A considerable diagnostic delay was evident, both a patient's and a doctor's delay. Preventive information about these alarming findings will be spread among clinicians in Sweden. Beside routine S-Li controls, additional check-ups are imperative in cases with unclear psychiatric or somatic symptoms.