Neuromuscular and Central Nervous System | Gastrointestinal | Weight Gain and Endocrine | Renal | Cardiovascular | Dermatological
Among the most common side effects in lithium therapy is tremor,
principally noticed in the fingers (Table 5–2). It resembles
intentional, coffee-induced, or familial tremor in frequency, being
faster than pseudoparkinsonian tremor. When tremor is severe enough
to affect handwriting, the writing is usually jagged and irregular,
but not micrographic as in parkinsonism. Tremor sometimes is worse
at peak lithium blood level and can be ameliorated by dosage rearrangement.
Dosage reduction can often be used to bring the blood level low
enough to make tremor either absent or mild and inconspicuous. If
there is good reason to maintain a serum lithium level that causes
a disturbing degree of tremor, propranolol at dosages ranging from
10 to 160 mg/day can be used to reduce the tremor.