A nurse is monitoring a client's response to receiving glipizide instead of guaifenesin. Which of the following actions should the nurse take?

A. Increase fluid intake. Clients taking lithium should increase fluid intake to 2-3 litres per day to prevent dehydration and maintain proper lithium excretion. Lithium is excreted by the kidneys, and dehydration can lead to toxic accumulation in the body. Adequate hydration also helps reduce the risk of side effects such as nephrotoxicity and lithium-induced polyuria.

B. Decrease sodium intake. Clients should not decrease sodium intake while on lithium. A low-sodium diet increases lithium reabsorption in the kidneys, leading to a higher risk of lithium toxicity. Instead, sodium intake should remain consistent, and clients should avoid excessive sodium restriction or sudden dietary changes.

C. Eat foods high in potassium. Potassium levels are not significantly affected by lithium therapy. While potassium is essential for overall health, increasing potassium intake is not a specific recommendation for lithium users. Potassium-rich foods are more relevant for clients taking diuretics (e.g., furosemide) or cardiac medications like digoxin.

D. Take the medication 1 hr before meals. Lithium is typically taken with food or milk to minimize gastrointestinal irritation. Taking it on an empty stomach can increase the likelihood of nausea and gastric discomfort, making it harder for clients to adhere to treatment. Clients should follow their provider’s instructions regarding meal timing.

• Client reports having three to four alcoholic beverages a couple times per week. Phenytoin metabolism is significantly affected by alcohol consumption. Chronic alcohol use increases phenytoin clearance, leading to subtherapeutic drug levels and seizure breakthrough. Conversely, acute alcohol intake inhibits phenytoin metabolism, increasing the risk of toxicity. The client should be counseled to avoid alcohol while on phenytoin therapy.
• Client takes diazepam as needed for anxiety. Diazepam is a CNS depressant that interacts with phenytoin, increasing sedation and the risk of respiratory depression. Both medications can cause drowsiness, dizziness, and impaired coordination, raising the risk of falls and injury. The provider should assess whether diazepam should be discontinued or adjusted when initiating phenytoin therapy.
• Last menstrual period was 3 months ago. Phenytoin is Pregnancy Category D, meaning it poses a significant teratogenic risk, including fetal hydantoin syndrome. The missed menstrual period suggests a possible pregnancy, which must be evaluated before starting phenytoin. A pregnancy test should be performed, and alternative antiseizure medications may need to be considered if pregnancy is confirmed.
• Client is a vegetarian and takes a multivitamin daily. Phenytoin interferes with the absorption of folic acid and vitamin D, both of which are crucial for bone health and red blood cell production. Vegetarians are already at higher risk for folate and vitamin B12 deficiency, making supplementation essential. However, multivitamins containing calcium, magnesium, or iron can decrease phenytoin absorption, reducing its effectiveness. The provider should review the multivitamin’s composition and adjust dosing schedules to prevent interactions.
• Temperature 36.4°C (97.6°F), oral. The client’s temperature is within normal range and does not indicate infection or systemic concerns that would affect phenytoin therapy.
• Heart rate 75/min, Respiratory rate 16/min, Blood pressure 100/74 mm Hg, Oxygen saturation 99% on room air.
  All vital signs are stable and do not indicate hemodynamic instability, respiratory depression, or cardiovascular issues that would contraindicate phenytoin administration.
• Skin color is consistent with genetic background. No rashes or lesions. The client has varicose veins. There are no signs of drug hypersensitivity reactions or dermatologic conditions that would require stopping phenytoin therapy.
• S1 S2 auscultated. No murmurs. All peripheral pulses 2+. Lung sounds clear bilaterally.
  There are no cardiopulmonary concerns that would indicate contraindications to phenytoin.
• Abdomen soft, nontender. Normoactive bowel sounds in all 4 quadrants. Last bowel movement was 3 days ago. Voids four to five times a day. Urine is clear, yellow, and odorless. Mild constipation is noted, but this is not a contraindication for phenytoin. The client should be encouraged to increase fiber and fluid intake to prevent worsening constipation, which can sometimes be a side effect of phenytoin.
• Alert and oriented to person, place, and time. Client has full range of motion and is able to maintain flexion against resistance in all four extremities. There are no neurological deficits requiring immediate intervention, and the client's baseline mental status is intact.