Option A, generalized muscle aches and pains, should be communicated to the health provider and the patient's creatine phosphokinase (CPK) levels should be monitored because the medication may need to be discontinued.
Flushing and pruritus after taking pravastatin, though not as frequent of a side effects, is a predictable outcome that may accompany the medication. It is not a significant finding that may indicate something averse is occurring.
Dizziness with rapid position changes or orthostatic hypotension can occur with patients being administered niacin, so they should be advise to change positions slowly.
Nausea when taking either medication, though not frequent, is a predictable outcome that may accompany the medication. It is also not a significant finding indicating something averse is occurring. If this graduates to vomiting, then the healthcare provider may need notified and the the waste sifted to investigate if the medication was also vomited.