pms-Lithium Carbonate Adverse Reactions

Mild side effects may be encountered even when serum lithium levels remain below 1 mEq/L. The most frequent side effects are the initial post-absorptive symptoms, believed to be associated with rapid rise in serum lithium levels. They include nausea, abdominal pain, vomiting, diarrhea, vertigo, muscle weakness, sleepiness and a dazed feeling, and frequently disappear after stabilization of therapy. The more common and persistent adverse reactions are: fine tremor of the hands which is not responsive to antiparkinson drugs, and at times, fatigue, thirst and polyuria (renal toxicity). These side effects may subside with continued treatment or a temporary reduction or cessation of dosage. If persistent, a lowering or cessation of dosage and reassessment of pms-LITHIUM CARBONATE therapy is indicated.
Mild to moderate toxic reactions may occur at lithium levels from 1.5 to 2 mEq/L, and moderate to severe reactions at levels above 2 mEq/L. Permanent neurological damage has been reported after exposure to toxic levels of lithium.
A number of patients may experience lithium accumulation during initial therapy, increasing to toxic levels and requiring immediate discontinuation of the drug. Some elderly patients with lowered renal clearances for lithium may also experience different degrees of lithium toxicity, requiring reduction or temporary withdrawal of medication. However, in patients with normal renal clearance the toxic manifestations appear to occur in a fairly regular sequence related to serum lithium levels. The usually transient gastrointestinal symptoms are the earliest side effects to occur. A mild degree of fine tremor of the hands may persist throughout therapy. Thirst and polyuria may be followed by increased drowsiness, ataxia, tinnitus, and blurred vision, indicating early intoxication. As intoxication progresses the following manifestations may be encountered: confusion, increasing disorientation, muscle twitching, hyperreflexia, nystagmus, seizures, diarrhea, vomiting and eventually coma and death.
The following toxic reactions have been reported and appear to be related to serum lithium levels, including levels within the therapeutic range.
Neuromuscular: tremor, muscle hyperirritability (fasciculations, twitching, clonic movements of whole limbs), ataxia choreoathetotic movements, hyperactive deep tendon reflexes.
CNS: blackout spells, epileptiform seizures, slurred speech, dizziness, vertigo, incontinence of urine or feces, somnolence, psychomotor retardation, restlessness, confusion, stupor, coma.
Cardiovascular: cardiac arrhythmia, hypotension, peripheral circulatory collapse.
Gastrointestinal: anorexia, nausea, vomiting, diarrhea.
Genitourinary: albuminuria, oliguria, polyuria, glycosuria.
Dermatologic: drying and thinning of hair, anesthesia of skin, acne, chronic folliculitis, xerosis cutis, alopecia and exacerbation of psoriasis.
Autonomic Nervous System: blurred vision, dry mouth.
Thyroid Abnormalities: euthyroid goiter and/or hypothyroidism (including myxedema) accompanied by lower T₃ and T₄ levels and elevated TSH. Iodine¹³¹ uptake may be elevated. On the average 5 to 15% of patients on long-term lithium therapy manifest clinical signs or have altered serum hormone levels (see Precautions). Paradoxically, rare cases of hyperthyroidism have been reported.
EEG Changes: diffuse slowing, widening of frequency spectrum, potentiation and disorganization of background rhythm.
ECG Changes: reversible flattening, isoelectricity or inversion of T waves.
Miscellaneous: fatigue, lethargy, transient scotomata, dehydration, weight loss, tendency to sleep.
Miscellaneous reactions frequently unrelated to dosage include: transient EEG and ECG changes, leucocytosis, headache, diffuse non-toxic goiter with or without hypothyroidism, transient hyperglycemia, generalized pruritus with or without rash, cutaneous ulcers, albuminuria, worsening of organic brain syndrome, excessive weight gain, edematous swelling of ankles or wrists, and thirst or polyuria, sometimes resembling diabetes insipidus, and metallic taste.
A single instance has been reported of the development of painful discoloration of fingers and toes and coldness of the extremities within one day of starting treatment with lithium. The mechanism through which these symptoms (resembling Raynaud's syndrome) developed is not known. Recovery followed discontinuance.
Serious reactions to long-term therapy: In addition to other possible adverse reactions, the main concern during chronic lithium therapy centres on the kidney function, the thyroid, parathyroid, the bones and skin.