Psychiatric Medications Q 62
Josefina is to be discharged on a regimen of lithium carbonate. In the teaching plan for discharge the nurse should include:
A. Advising the client to watch the diet carefully.
B. Suggesting that the client take the pills with milk.
C. Reminding the client that a CBC must be done once a month.
D. Encouraging the client to have blood levels checked as ordered.
Correct Answer: D. Encouraging the client to have blood levels checked as ordered.
Blood levels must be checked monthly or bimonthly when the client is on maintenance therapy because there is only a small range between therapeutic and toxic levels. Monitoring of therapeutic levels includes trough plasma levels drawn 8 to 12 hours after the last dose. The therapeutic range is 1.0 to 1.5 mEq/L for acute treatment and 0.6 to 1.2 mEq/L for chronic therapy. Monitoring should be done every 1 to 2 weeks until reaching the desired therapeutic levels.
Option A: It is also important to monitor patients for dehydration and lower the dose when there are signs of infection, excessive sweating, or diarrhea. Toxic levels are when the drug level is more than 2 mEq/L. Lithium has a very narrow therapeutic index, and toxic levels are when the drug is above 2 mEq/L, which is very close to its therapeutic range. Lithium toxicity can cause interstitial nephritis, arrhythmia, sick sinus syndrome, hypotension, T wave abnormalities, and bradycardia.
Option B: Lithium toxicity has no antidote. Treatment for lithium toxicity is primarily hydration and to stop the drug. Give hydration with normal saline, which will also enhance lithium excretion. Avoid all diuretics. If the patient has severe renal dysfunction or failure, or severely altered mental status, then start with hemodialysis. 20 to 30 mg of propranolol given 2 to 3 times per day may help reduce tremors.
Option C: Before starting treatment with lithium, it is essential to get kidney function tests and thyroid function tests. In patients above 50 years of age, an electrocardiogram is also necessary. Repeat these tests once or twice a year in patients on lithium therapy. Because lithium is associated with weight gain, it is important to weigh a patient before starting treatment. It is also beneficial to determine if the patient has prediabetes, diabetes, or dyslipidemia.