Pharmacology Miscellaneous Neurological Condition Drugs #5

Question

The nurse caring for a patient performs a focused assessment after the patient complained of dizziness two hours after the nurse administered propranolol hydrochloride. The heart rate prior to administration was 63 beats per minute (bpm). The heart rate is now 34 bpm. Which priority medication will the nurse prepare to administer?

Answers

  1. Atropine
    • Rationale:

      This answer is correct because one major use of atropine is treatment of bradyarrhythmias. IV administration of atropine is utilized to reverse bradycardia and help restore cardiac output to the patient. It is also used in higher doses during asystole. Other uses of atropine are used as an anticholinergic for decreasing secretions and use as an antidote for cholinesterase poisoning.

  2. Sodium nitroprusside
    • Rationale:

      This answer is not correct because sodium nitroprusside is a vasodilator and will cause profound hypotension. The added effect to the hypotension that will occur with propranolol will be very dangerous. Atropine should be administered for helping reverse the profound bradycardia related to the propranolol.

  3. Digoxin
    • Rationale:

      This answer is not correct because digoxin is a cardiac glycoside and will lower the heart rate to a lethal level. Atropine should be administered for helping reverse the profound bradycardia related to the propranolol.

  4. Dobutamine
    • Rationale:

      This answer is not correct because although dobutamine may increase the heart rate and blood pressure, it does so by imposing a sympathetic action on the body. Propranolol is a beta blocker and it will negate the effects of dobutamine. Therefore, atropine is the best medication to be administered since it will increase the heart rate only.

Overview

Atropine is a known antidote for propranolol. It is administered to treat symptomatic bradycardia (decreased heart rate).

Explanation

The correct answer is A since atropine is a known antidote for propranolol. Initial dose may be 5 to 15 mg slow IVP followed by infusion rate of 5-15 mg/hr. Treatment may also include calcium gluconate 30 mL (if non central line) or 10 mL calcium chloride (usually through large bore or central line due to extravasation risks); and glucagon 50ug/kg or 3-5 mg up to 10 mg. Glucagon increases cardiac cyclic adenosine monophosphate (camp) and enhances inotropic effects. (note: glucagon may also help reverse CCB toxicity). Nitroprusside produces hypotension and may decrease heart rate and caution giving with propranolol may result in profound hypotension. Dobutamine may increase heart rate but cannot be used with propranolol since beta blockers may negate the effect of dobutamine.

Learning Outcomes

Atropine is an antimuscarinic (anticholinergic) medication with multiple actions and uses. One major use is treatment of symptomatic bradyarrhythmias. IV administration of atropine is utilized to reverse bradycardia and help restore cardiac output to the patient. It is also used in higher doses during asystole. Other uses of atropine are used as an anticholinergic for decreasing secretions and use as an antidote for cholinesterase poisoning.

Test Taking Tip

Remember “-olol” is associated with beta blocking medications, such as atenolol and propranolol.

Video Rationale