Which phase of pharmacokinetics involves the movement of a drug from its site of administration to the bloodstream?

Choice A reason: CT scan with contrast is an order that the nurse should question for the client who is taking metformin for hyperglycemia. Metformin is a medication that lowers the blood glucose level by decreasing the hepatic glucose production and increasing the insulin sensitivity¹. Metformin can cause a rare but serious complication called lactic acidosis, which is a buildup of lactic acid in the blood that can cause symptoms such as weakness, nausea, vomiting, or breathing problems. CT scan with contrast involves injecting iodinated contrast material into the bloodstream, which can affect the kidney function and increase the risk of lactic acidosis in patients taking metformin. The nurse should consult with the prescriber and the pharmacist about the need to stop metformin before and after the CT scan with contrast, and to monitor the kidney function and the blood glucose level of the client.

Choice B reason: Chest X-ray 1 view is not an order that the nurse should question for the client who is taking metformin for hyperglycemia. Chest X-ray is a diagnostic test that uses a small amount of radiation to produce images of the lungs, heart, and chest wall. Chest X-ray does not involve any contrast material or affect the kidney function or the blood glucose level. The nurse should follow the standard precautions and procedures for performing a chest X-ray, such as verifying the client's identity, checking for pregnancy, removing any metal objects, and positioning the client properly.

Choice C reason: V/Q scan is not an order that the nurse should question for the client who is taking metformin for hyperglycemia. V/Q scan is a diagnostic test that measures the ventilation and perfusion of the lungs, and can detect any abnormalities such as pulmonary embolism or chronic obstructive pulmonary disease. V/Q scan involves injecting a radioactive tracer into the bloodstream and inhaling a radioactive gas, which are then detected by a special camera. V/Q scan does not affect the kidney function or the blood glucose level. The nurse should follow the standard precautions and procedures for performing a V/Q scan, such as verifying the client's identity, checking for allergies, explaining the procedure, and monitoring the vital signs.

Choice D reason: Bilateral lower extremity ultrasound is not an order that the nurse should question for the client who is taking metformin for hyperglycemia. Bilateral lower extremity ultrasound is a diagnostic test that uses sound waves to produce images of the blood vessels in the legs, and can detect any abnormalities such as deep vein thrombosis or peripheral arterial disease. Bilateral lower extremity ultrasound does not involve any contrast material or affect the kidney function or the blood glucose level. The nurse should follow the standard precautions and procedures for performing a bilateral lower extremity ultrasound, such as verifying the client's identity, explaining the procedure, and applying a gel and a probe to the legs.

Choice A reason: Tinnitus is a rare side effect of Flexeril, which is a medication that relaxes the muscles and relieves pain and stiffness¹. Tinnitus is a ringing or buzzing sound in the ears that can be caused by various factors, such as ear infections, noise exposure, or certain medications. Flexeril does not affect the auditory system directly, but it can cause confusion or dizziness, which may worsen the perception of tinnitus.

Choice B reason: Drowsiness is the most common side effect of Flexeril, which is a medication that relaxes the muscles and relieves pain and stiffness¹. Drowsiness occurs because Flexeril has sedative and anticholinergic properties, which means that it blocks the action of acetylcholine, a neurotransmitter that regulates arousal and alertness. Flexeril can impair the mental and physical abilities, especially in elderly patients or those who take other medications that cause drowsiness¹. The nurse should educate the patient about the risk of drowsiness and advise them to avoid driving or operating machinery while taking Flexeril.

Choice C reason: Diarrhea is not a common side effect of Flexeril, which is a medication that relaxes the muscles and relieves pain and stiffness¹. Diarrhea is a condition that causes loose or watery stools, which can be caused by various factors, such as infections, food intolerance, or certain medications. Flexeril does not affect the gastrointestinal system directly, but it can cause dry mouth, nausea, or constipation, which may alter the bowel movements¹.

Choice D reason: Palpitations are not a common side effect of Flexeril, which is a medication that relaxes the muscles and relieves pain and stiffness¹. Palpitations are a sensation of rapid or irregular heartbeat, which can be caused by various factors, such as stress, anxiety, caffeine, or certain medications. Flexeril does not affect the cardiac system directly, but it can lower the blood pressure or interact with other medications that affect the heart rate, such as betablockers or antidepressants¹.