home > drugs a-z list > dutoprol (metroprolol) drug center > dutoprol (metroprolol) drug - overdosage and contraindications

Metoprolol and Hydrochlorothiazide

The most frequently observed signs expected with overdosage of a beta-blocker are bradycardia and hypotension. Lethargy is also common, and with severe overdoses, delirium, coma, convulsions, and respiratory arrest have been reported to occur. Congestive heart failure, bronchospasm, and hypoglycemia may occur, particularly in patients with underlying conditions. With thiazide diuretics, acute intoxication is rare. The most prominent feature of overdose is acute loss of fluid and electrolytes. Signs and symptoms include cardiovascular (tachycardia, hypotension, shock), neuromuscular (weakness, confusion, dizziness, cramps of the calf muscles, paresthesia, fatigue, impairment of consciousness), gastrointestinal (nausea, vomiting, thirst) renal (polyuria, oliguria, or anuria [due to hemoconcentration]), and laboratory findings (hypokalemia, hyponatremia, hypochloremia, alkalosis, increased BUN [especially in patients with renal insufficiency]).

If overdosage of metoprolol and hydrochlorothiazide is suspected, the patient should be observed closely. Treatment is symptomatic and supportive; there is no specific antidote. Limited data suggest metoprolol is not dialyzable; similarly, there is no indication that hydrochlorothiazide is dialyzable. Suggested general measures include induction of emesis and/or gastric lavage, administration of activated charcoal, respiratory support, correction of fluid and electrolyte imbalance, and treatment of convulsions. Based on the expected pharmacologic actions and recommendations for other beta blockers and hydrochlorothiazide, the following measures should be considered when clinically warranted.

Bradycardia

Administer IV atropine. If the response is inadequate, isoproterenol or another agent with positive chronotropic properties may be given cautiously. Under some circumstances, transvenous pacemaker insertion may be necessary.

Hypotension, Shock

The patient's legs should be elevated. IV fluids should be administered and lost electrolytes (potassium, sodium) replaced. Intravenous glucagon may be useful. Vasopressors should be considered.

Heart Block (second or third degree)

Patients should be carefully monitored and treated with isoproterenol infusion or transvenous cardiac pacemaker insertion, as appropriate.

Congestive Heart Failure

Initiate conventional therapy (ie, digitalis, diuretics, vasodilating agents, inotropic agents).

Bronchospasm

Administer a bronchodilator such as isoproterenol and/or aminophylline.

Hypoglycemia

Administer IV glucose. Surveillance: Fluid and electrolyte balance (especially serum potassium) and renal function should be monitored until normalized.

Metoprolol succinate extended release/hydrochlorothiazide is contraindicated in patients in cardiogenic shock, overt cardiac failure (see WARNINGS), second or third degree AV block, marked sinus bradycardia, anuria, and hypersensitivity to either component of this product or to other sulfonamide-derived drugs.

Last reviewed on RxList: 1/9/2012
This monograph has been modified to include the generic and brand name in many instances.