6 Mood Stabilizers

Monitoring differs by medicine

Mood stabilizers include lithium and medicines also used to treat seizures, such as valproate, carbamazepine, and lamotrigine. Their monitoring needs differ. Clinical decisions should follow the prescriber’s instructions and current guidance.

Lithium: baseline checks and levels

Before starting lithium, assess kidney function, electrolytes, calcium, thyroid function, and weight or body mass index. These baseline checks help clinicians assess risks and interpret later results. An ECG may also be appropriate for someone with cardiovascular disease or risk factors.

After starting lithium or changing its dose, check the level about one week later, then weekly until it is stable. A 12-hour trough—measured 12 hours after the last dose—is commonly used for consistent interpretation. The clinician interprets the result in context; a number alone does not rule out toxicity.

Dehydration, fluid or salt loss, and some interacting medicines can raise lithium concentrations and increase toxicity risk. These include NSAIDs such as ibuprofen, thiazide diuretics, and medicines affecting the renin–angiotensin system, including ACE inhibitors and ARBs. Intercurrent illness or a major change in fluid or salt intake can also increase risk. Contact the prescriber for advice about monitoring when starting one of these medicines or when these circumstances arise.

Recognizing possible lithium toxicity

Vomiting, worsening tremor, unsteady walking, and confusion—especially after diarrhea or other fluid loss—raise concern for possible lithium toxicity. Toxicity may include gastrointestinal symptoms, coarse tremor, ataxia, and confusion; serious cases can involve seizures.

Suspected toxicity requires urgent medical assessment. Contact the prescriber or emergency services promptly, and do not try to manage it by changing the dose without medical advice.

Valproate: laboratory and symptom monitoring

Unusual lethargy, confusion, and vomiting in someone taking valproate should prompt consideration of hyperammonemia with encephalopathy. A clinician may check an ammonia level. Valproate also requires liver-function monitoring and monitoring for blood-count or bleeding problems.

Lamotrigine: rash and gradual titration

A new rash after starting lamotrigine needs prompt medical advice. Lamotrigine can rarely cause serious, potentially life-threatening skin reactions. Prescribing information advises stopping it at the first sign of rash unless the rash is clearly unrelated.

Start and increase lamotrigine gradually as directed. Exceeding the recommended titration or taking valproate at the same time can increase rash risk.

Carbamazepine: ongoing monitoring

Carbamazepine monitoring includes baseline blood counts and baseline and periodic liver-function tests. Clinicians may also use drug levels when needed, such as when toxicity, adherence, or a change in response is in question.