0071643192.pdf

TOXICOLOGY

■ Muscarinic receptor antagonism →anticholinergic symptoms.
■ Histamine receptor antagonism →sedation.
■ Cardiac K+channel blockade →prolonged qTc.

SYMPTOMS/EXAM

■ Adverse effects related to nonspecific receptor blockade are common
(see Table 6.12).
■ Again, typical agents are more likely to have adverse effects than atypical
agents.
■ Findings in acute overdose are an extension of these adverse effects.

DIAGNOSIS

■ Clinical diagnosis is based on history of exposure, physical exam findings.
■ ECG is used to monitor prolonged qTc

TREATMENT

■ Supportive therapy
■ Continuous monitoring

TABLE 6.12. Adverse Effects of Antipsychotics

ADVERSEEFFECT MECHANISM/TOXICITY SYMPTOMS/EXAM TREATMENT

Extrapyramidal Basal ganglia dopamine See Table 6.13.

symptoms receptor antagonism

Neuroleptic Anterior hypothalamus Altered mental status Stop medication.

malignant and basal ganglia Hyperthermia Benzodiazepines

syndrome (NMS) dopamine receptor Muscular rigidity Intubate and paralyze

antagonism as needed.

Altered mental Histamine and muscarinic Agitated delirium Benzodiazepines for agitation

status receptor antagonism Somnolence Support airway as needed.

Coma

Hypotension α 1 -Adrenergic receptor Mild to moderate hypotension Intravenous fluids

antagonism Pressors may be needed.

Tachycardia α 1 -Adrenergic Mild to moderate sinus

(reflex tachycardia) and tachycardia

muscarinic receptor

antagonism

Prolonged qTc K+channel blockade Theoretical concern for torsades Cardiac monitoring

de pointes, but rare Check electrolytes.

Treat torsades using standard

therapies.

Blood dyscrasias Adverse drug effect associated Agranulocytosis, leukopenia, Stop medication.

with clozaril neutropenia.