An older adult client is being discharged after a myocardial infarction (MI) and receives a new prescription for atenolol. Which instruction is most important for the nurse to include in this client's teaching plan?

A. Avoid driving or operating machinery: Drowsiness and dizziness can occur with atenolol, especially when initiating therapy, but these effects are usually mild. While it's reasonable to use caution initially, this is not the most critical teaching point compared to orthostatic safety.B. Take a missed dose as soon as possible: Although this may seem helpful, patients should not double doses or take extra doses close together. If a significant amount of time has passed, the missed dose may need to be skipped to prevent bradycardia or hypotension.C. Standing slowly when getting up from bed: Atenolol, a beta-blocker, can cause orthostatic hypotension, especially in older adults. Teaching the client to rise slowly helps reduce the risk of dizziness and falls, making this a high-priority safety instruction following discharge.D. Avoid intake of alcoholic beverages: Alcohol may enhance the hypotensive effects of beta-blockers, but moderate consumption is not strictly contraindicated. This advice is relevant but less urgent than preventing injury from orthostatic hypotension.