SIDE EFFECTS
The occurrence and severity of adverse reactions are
generally directly related to serum lithium concentrations and to individual
patient sensitivity to lithium. They generally occur more frequently and with
greater severity at higher concentrations.
Adverse reactions may be encountered at serum lithium
concentrations below 1.5 mEq/L. Mild to moderate adverse reactions may occur at
concentrations from 1.5 to 2.5 mEq/L, and moderate to severe reactions may be
seen at concentrations from 2.0 mEq/L and above.
Fine hand tremor, polyuria, and mild thirst may occur
during initial therapy for the acute manic phase and may persist throughout
treatment. Transient and mild nausea and general discomfort may also appear during
the first few days of lithium administration.
These side effects usually subside with continued
treatment or with a temporary reduction or cessation of dosage. If persistent,
a cessation of lithium therapy may be required. Diarrhea, vomiting, drowsiness,
muscular weakness, and lack of coordination may be early signs of lithium
intoxication, and can occur at lithium concentrations below 2.0 mEq/L. At
higher concentrations, giddiness, ataxia, blurred vision, tinnitus, and a large
output of dilute urine may be seen. Serum lithium concentrations above 3.0
mEq/L may produce a complex clinical picture involving multiple organs and
organ systems. Serum lithium concentrations should not be permitted to exceed
2.0 mEq/L during the acute treatment phase.
The following reactions have been reported and appear to
be related to serum lithium concentrations, including concentrations within the
therapeutic range:
Central Nervous System: tremor, muscle
hyperirritability (fasciculations, twitching, clonic movements of whole limbs),
hypertonicity, ataxia, choreoathetotic movements, hyperactive deep tendon
reflex, extrapyramidal symptoms including acute dystonia, cogwheel rigidity,
blackout spells, epileptiform seizures, slurred speech, dizziness, vertigo,
downbeat nystagmus, incontinence of urine or feces, somnolence, psychomotor
retardation, restlessness, confusion, stupor, coma, tongue movements, tics, tinnitus,
hallucinations, poor memory, slowed intellectual functioning, startled
response, worsening of organic brain syndromes. Cases of Pseudotumor cerebri
(increased intracranial pressure and papilledema) have been reported with
lithium use. If undetected, this condition may result in enlargement of the
blind spot, constriction of visual fields and eventual blindness due to optic
atrophy. Lithium should be discontinued, if clinically possible, if this
syndrome occurs.
Cardiovascular: cardiac arrhythmia, hypotension,
peripheral circulatory collapse, bradycardia, sinus node dysfunction with severe
bradycardia (which may result in syncope), Unmasking of Brugada Syndrome (See
WARNINGS and PATIENT INFORMATION).
Gastrointestinal:
anorexia, nausea, vomiting, diarrhea, gastritis, salivary gland swelling,
abdominal pain, excessive salivation, flatulence, indigestion.
Genitourinary:
glycosuria, decreased creatinine clearance, albuminuria, oliguria, and symptoms
of nephrogenic diabetes insipidus including polyuria, thirst and polydipsia.
Dermatologic:
drying and thinning of hair, alopecia, anesthesia of skin, acne, chronic
folliculitis, xerosis cutis, psoriasis or its exacerbation, generalized
pruritus with or without rash, cutaneous ulcers, angioedema.
Autonomic
Nervous System: blurred vision, dry mouth, impotence/sexual dysfunction.
Thyroid
Abnormalities: euthyroid goiter and/or hypothyroidism (including myxedema)
accompanied by lower T3 and T4. 131Iodine uptake may be elevated
(see PRECAUTIONS). Paradoxically, rare cases of hyperthyroidism have
been reported.
EEG Changes: diffuse slowing, widening of frequency
spectrum, potentiation and disorganization of background rhythm.
EKG Changes: reversible flattening, isoelectricity or inversion of T-waves.
Miscellaneous
: fatigue, lethargy, transient scotomata, exophthalmos, dehydration, weight
loss, leucocytosis, headache, transient hyperglycemia, hypercalcemia,
hyperparathyroidism, albuminuria, excessive weight gain, edematous swelling of
ankles or wrists, metallic taste, dysgeusia/taste distortion, salty taste,
thirst, swollen lips, tightness in chest, swollen and/or painful joints, fever,
polyarthralgia, and dental caries.
Some reports of nephrogenic diabetes insipidus,
hyperparathyroidism, and hypothyroidism which persist after lithium
discontinuation have been received.
A few reports have been received of the development of
painful discoloration of fingers and toes and coldness of the extremities
within one day of starting lithium treatment. The mechanism through which these
symptoms (resembling Raynaud's Syndrome) developed is not known. Recovery
followed discontinuance.
DRUG INTERACTIONS
No information provided.