Which of the following is not listed as a lithium adverse effect in LMNOPP?

• A. Hyperkalemia
• B. Movement problems
• C. Nephrogenic DI
• D. Hypothyroidism

Answer: (A)

LMNOPP is a mnemonic used to recall common lithium adverse effects. It highlights movement problems (such as tremor), nephrogenic diabetes insipidus, and hypothyroidism. Hyperkalemia is not included in this list, so it isn’t considered a standard adverse effect of lithium in LMNOPP. The movement issues come from lithium’s effects on the CNS, the nephrogenic DI from interference with vasopressin signaling in the kidney’s collecting ducts, and hypothyroidism from lithium’s impact on thyroid hormone synthesis and release. In short, hyperkalemia isn’t a typical lithium adverse effect represented by this mnemonic.