Does Lithium Cause Incontinence?
Yes, lithium can cause urinary incontinence, though this is an uncommon adverse effect that occurs in approximately 17% of patients based on available data.
Evidence from FDA Drug Label
The FDA-approved lithium drug label explicitly lists "incontinence of urine or feces" as a recognized adverse reaction under Central Nervous System effects 1. Importantly, this adverse effect is noted as one that "does not appear to be directly related to serum lithium levels," meaning it can occur even when lithium levels are within therapeutic range 1.
Clinical Evidence
A prospective study of 23 consecutive female outpatients found that 4 patients (17%) developed significant urinary urgency or urgency incontinence when treated with lithium carbonate 2. This is a notable incidence rate that clinicians should be aware of when prescribing lithium.
Mechanism
The proposed mechanism involves lithium-induced changes in bladder cholinergic-adrenergic balance 2. This disruption affects normal bladder control mechanisms, leading to urgency-type incontinence symptoms.
Management Approach
When lithium-induced incontinence occurs, the following interventions have shown efficacy:
- Addition of oxybutynin (an anticholinergic medication)
- Addition of imipramine (a tricyclic antidepressant with anticholinergic properties)
- Reduction of lithium dosage 2
All three approaches led to remission or significant improvement of incontinence symptoms in the reported cases.
Additional Urinary Concerns
Beyond incontinence, lithium commonly causes:
- Polyuria (increased urine output)
- Polydipsia (increased thirst)
- Symptoms resembling diabetes insipidus 1
These effects are more common than frank incontinence and may occur during initial therapy.
Clinical Pitfall
A recent pharmacovigilance analysis of the Italian spontaneous reporting database identified lithium as having a statistically significant signal for urinary retention rather than incontinence 3. This represents the opposite problem and highlights that lithium can affect bladder function bidirectionally. Clinicians should monitor for both retention and incontinence when patients report urinary symptoms on lithium.
Monitoring Recommendation
When prescribing lithium, specifically ask patients about new urinary symptoms including urgency, frequency, and incontinence. If incontinence develops, consider the management strategies above rather than immediately discontinuing lithium, as the psychiatric benefits may outweigh this manageable side effect in many patients.