The nurse is providing medication teaching to a client with bipolar disorder who receives a prescription for lithium carbonate. Which instruction should the nurse emphasize with the client?

A) Keep medication refrigerated:
Metronidazole tablets do not typically require refrigeration. Storing the medication at room temperature is usually sufficient. Refrigeration may not be necessary and could potentially lead to confusion or unnecessary inconvenience for the client.

B) Drink a liter of water daily:
While maintaining hydration is generally important for overall health, there's no specific requirement to drink a liter of water daily solely because of metronidazole therapy. However, encouraging adequate fluid intake is beneficial to prevent dehydration, especially if diarrhea is present due to Clostridium difficile infection.

C) Take one hour after eating:
Metronidazole can be taken with or without food. It's generally well tolerated with food to reduce gastrointestinal side effects such as nausea. However, taking it with food or on an empty stomach does not significantly affect its effectiveness.

D) Avoid the use of alcohol:
This is the correct answer. Consuming alcohol while taking metronidazole can lead to a disulfiram-like reaction, characterized by symptoms such as flushing, headache, nausea, vomiting, and abdominal cramps. This reaction occurs because metronidazole inhibits the breakdown of acetaldehyde, leading to its accumulation in the body when alcohol is consumed. Therefore, it's crucial to advise clients to abstain from alcohol during metronidazole therapy and for at least 48 hours after completing the course of treatment.

A) Schedule both medications at bedtime:
Administering both medications at bedtime may not be the most appropriate schedule. PTU is typically administered multiple times a day to maintain consistent therapeutic levels in the bloodstream. Additionally, administering Lugol’s solution at bedtime may not provide sufficient time for the iodine to take effect before the PTU.

B) Administer iodine one hour before PTU:
This option is correct. Lugol’s solution, a strong iodine solution, is often given before antithyroid medications such as PTU or methimazole to temporarily block thyroid hormone production. Administering iodine about one hour before PTU allows the iodine to be taken up by the thyroid gland, effectively reducing thyroid hormone synthesis before the PTU starts to inhibit the conversion of T4 to T3.

C) Give parental dose once every 24 hours:
This option does not address the timing of administration between PTU and Lugol’s solution. While it may be correct for the dosing frequency of PTU, it does not specify when to administer Lugol’s solution in relation to PTU.

D) Offer both drugs together with a meal:
Administering both drugs together with a meal may not be appropriate, especially considering that Lugol’s solution needs to be absorbed into the bloodstream to exert its effect on the thyroid gland. Administering Lugol’s solution and PTU together may not allow adequate time for the iodine to take effect before the PTU starts to inhibit thyroid hormone production.