Final answer:
Lithium levels are usually checked 12 hours after the last dose, with a target therapeutic range of 0.6 to 1.2 mEq/L. For new prescriptions, levels are checked after 5-7 days or after a dose change. For stable patients, the levels are monitored every 3-6 months.
Step-by-step explanation:
The lithium level is typically checked 12 hours after the last dose, which is often known as the trough level. Lithium levels are monitored to ensure they are within the therapeutic range, which is usually between 0.6 to 1.2 mEq/L. It is crucial to monitor these levels because lithium has a narrow therapeutic window and can be toxic if levels get too high. Additionally, frequency of monitoring varies depending on whether the drug is newly prescribed or if the client has been on a stable dose for a long time. Normally, when the prescription is new, the levels are checked 5-7 days after starting the medication or after a dose change. Once stable therapeutic levels are achieved and the client's condition is stable, lithium levels may be checked every 3-6 months.