0071643192.pdf

TOXICOLOGY

Complications of chronic use include angioedema, nonproductive cough,
renal insufficiency (with renal artery stenosis).

MECHANISM/TOXICITY

■ ACE-I: Decreased angiotensin II formation
■ ARB: Block the receptor for angiotensin II on the blood vessels, heart, and
adrenal cortex
■ Blockage of angiotensin II results in decreased aldosterone release (→
decreased sodium and water retention) and vasodilation.

SYMPTOMS/EXAM

■ Mild hypotension
■ Hyperkalemia

DIAGNOSIS

■ Usually obvious from patient’s history

TREATMENT

■ Supportive care with IV fluids and pressors (if needed) is usually sufficient.

Clonidine

An imidazoline compound prescribed for the treatment of hypertension. It is
also used for treatment of pediatric behavioral disorders.

MECHANISM/TOXICITY

■ Central postsynaptic α 2 -adrenergic agonist → decreased sympathetic
(norepinephrine) outflow →decreased HR and BP.
■ Peripherally this postsynaptic αagonism may result in vasoconstriction
and paradoxical transient hypertension.

SYMPTOMS/EXAM

■ Initial, short-lived hypertension progresses to hypotension and bradycardia.
■ Hypoventilation with hypoxia
■ Mental status changes and coma
■ Miosis

TABLE 6.15. Indications for Digoxin-Specific Antibodies

INDICATIONS FORDIGOXIN-SPECIFICANTIBODIES

Ventricular dysrhythmias

Bradycardia unresponsive to therapy

K+> 5.0 mEq/dL in acute ingestion

Potentially massive overdose

Serious toxicity is not expected

in ACE-I or ARB overdose as a

single agent.