During an intravenous dose of methocarbamol for a client with multiple sclerosis, which adverse effect should the nurse monitor?

• A. Bradycardia
• B. Tachycardia
• C. Hyperglycemia
• D. Rash

Answer: (A)

Central nervous system–acting muscle relaxants given IV can affect autonomic regulation and slow the heart rate. Methocarbamol, when administered intravenously, has a recognized potential to cause bradycardia, especially with rapid infusion or in patients with autonomic instability as seen in multiple sclerosis. Because a slower heart rate can reduce cardiac output and lead to dizziness, fainting, or hypotension, the nurse should monitor the patient’s heart rate and blood pressure closely during and after administration. Be alert for symptoms of bradycardia and be prepared to follow protocol if the heart rate falls or symptoms develop. While rash can occur with many drugs and hyperglycemia or tachycardia aren’t typical primary concerns with this IV use, bradycardia is the adverse effect that warrants vigilant monitoring here.