Vomiting, diarrhoea, intercurrent infection, fluid deprivation and drugs likely to upset electrolyte balance, such as diuretics, may all reduce lithium excretion and thereby precipitate intoxication; reduction of dosage may be required. Use with care in elderly patients as lithium excretion may also be reduced.
The possibility of hypothyroidism and of renal dysfunction arising during prolonged treatment should be borne in mind and periodic assessments made.
Brugada syndrome
Lithium may unmask or aggravate Brugada syndrome, a hereditary disease of the cardiac sodium channel with characteristic electrocardiographic changes (right bundle branch block and ST segment elevation in right precordial leads), which may lead to cardiac arrest or sudden death. Lithium is not recommended in patients with known Brugada syndrome or a family history of Brugada syndrome (see Section 4.3). Caution is advised in patients with a family history of cardiac arrest or sudden death.
Histological changes (including tubulointerstitial nephropathy) have been reported after long-term treatment with lithium. These changes may lead to impaired renal function. It is unclear if these changes are always reversible on stopping lithium. It is advisable to monitor renal function periodically.
Lithium therapy may lower the seizure threshold and increase the risks of neurological adverse effects following electroconvulsive therapy (ECT). If ECT is administered to patients on lithium therapy, lithium levels should checked beforehand to ensure that they are moderate (around 0.4-1 mmol/l) and a low electrical dose at the first treatment should be considered.
Patients receiving neuroleptics concomitantly with lithium should be monitored closely for early evidence of neurologic toxicity and treatment discontinued promptly if symptoms appear. On extremely rare occasions, the concurrent administration of lithium with neuroleptics may result in an encephalopathic syndrome, (characterised by delirium, seizures or an increased incidence of extrapyramidal symptoms) which may be similar to or the same as neuroleptic malignant syndrome. In some instances, the syndrome was followed by irreversible brain damage. See section 4.5 (Interaction with Other Medicaments and Other Forms of Interaction)
Patients should be warned of the symptoms of impending intoxication (see Section 4.8), of the urgency of immediate action should these symptoms appear, and also of the need to maintain a constant and adequate salt and water intake. Outpatients should be warned to take their medication at the stipulated time. If a dose is missed, the patient should wait until the next scheduled time of dosing. A double dose to make up for the dose that has been missed should not be taken. Treatment should be discontinued immediately on the first signs of toxicity, which include cardiovascular, renal, neurological and gastrointestinal events (see Section 4.8). Acute renal failure has been reported rarely with lithium toxicity.
Renal tumours: Cases of microcysts, oncocytomas and collecting duct renal carcinoma have been reported in patients with severe renal impairment who received lithium for more than 10 years (see Section 4.8).
Patients with the rare hereditary galactose intolerance, Lapp lactase deficiency or glucose-galactose malabsorption should not take Liskonum.
In patients who have undergone bariatric surgery, a lower maintenance dose of lithium may be required. Lithium levels should be closely monitored due to the risk of lithium toxicity until weight has stabilized.
Lithium should be used with particular care in the elderly since this group may be particularly susceptible to toxicity due to decreasing renal function and hence elimination (see Dosage and Administration).
Patients with bipolar disorder may experience worsening of their depressive symptoms and/or the emergence of suicidal ideation and behaviours (suicidality) whether or not they are taking medications for bipolar disorder. Patients should be closely monitored for clinical worsening and suicidality, especially at the beginning of a course of treatment, or at the time of dose changes.
Patients (and caregivers of patients) should be alerted about the need to monitor for any worsening of their condition and/or the emergence of suicidal ideation/behaviours or thoughts of harming themselves and to seek medical advice immediately if these symptoms present.