A nurse is caring for a client who has bipolar disorder and is taking lithium. The client reports blurred vision and nausea. Which of the following actions should the nurse take?

Choice A reason: Resting with eyes closed may temporarily relieve blurred vision but does not address the underlying issue of possible lithium toxicity. Choice B reason: Blurred vision and nausea are signs of lithium toxicity. The nurse should withhold the medication and notify the provider immediately to prevent worsening toxicity. Choice C reason: Waiting to re-check in 4 hours delays intervention and increases risk of harm. Choice D reason: Administering the next dose despite symptoms could worsen toxicity and endanger the client.