Consult Liaison

Clozapine Metabolism & Infection/Inflammation

Major infection or inflammation slows CYP metabolization of clozapine. Hospitalized patients in an inflammatory state should have clozapine doses decreased by $50\%$.

Clozapine Metabolism & Smoking

Smoking accelerates CYP metabolization of clozapine. Adjust dose up or down by $\frac{1}{3}$ when returning to or stopping smoking, respectively.

Target Clozapine/Norclozapine Ratio

Target ratio is $1.5 - 2.5$. Values significantly out of range (such as $1$ or $3$) suggest metabolic changes or adherence issues.

Depakote Hyperammonemia Management

Add L-carnitine $660\,\text{mg TID}$ to $990\,\text{mg BID}$ to lower ammonia levels, then maintain L-carnitine. Intellectual disability, developmental delay, and dementia patients can exhibit toxicity even within normal ammonia ranges.

Cannabis Hyperemesis Syndrome (CHS)

Can onset even after a slight reduction in cannabis use. Symptom relief by hot showers is pathognomonic.

Catatonia & Iron Levels

Check iron levels in catatonia because low iron increases the risk of malignant catatonia and worsens response to benzodiazepines.

Capacity Assessment Mnemonic (CRAP)

Stands for: **C**lear and consistent choice, **R**easoning, **A**ppreciation, and **P**ossesses understanding (risks, benefits, alternatives).

Dispositional Capacity

Evaluated prior to discharge; consists of **Agency** (ability to manipulate resources to meet needs) and **Praxis** (functional ability to meet needs).

Agitated Catatonia Assessment

A severely mentally ill patient presenting with elevated blood pressure and tachycardia should be assessed for agitated catatonia.

Clozapine Management in Catatonia

Clozapine is the only antipsychotic not stopped or changed if a patient becomes catatonic because it has minimal $D_2$ receptor antagonism.

Catatonia Medical Monitoring

Life-threatening state: monitor leg swelling/chest pain/dyspnea (DVT/PE), blood pressure (hypotension/dehydration), weight trends (malnutrition), and horizontal nystagmus (indicator of exceeding benzodiazepine tolerance threshold).

Catatonia Treatment

IV Ativan is preferred due to rapid, high peak serum concentrations entering the brain faster. Amantadine or memantine (NMDA receptor antagonists) can be added as adjunctive therapy.