CAMCOLIT Film-coated tablet Ref.[27663] Active ingredients: Lithium

Camcolit 400 mg tablets are usually administered according to a twice daily regimen.

When lithium levels have stabilised, a once daily regimen may be preferred

Lithium carbonate has a narrow therapeutic window. The dose required for treatment must be titrated and adjusted on the basis of regular monitoring of the serum concentration (see section 4.4).

Lithium therapy should not be initiated unless adequate facilities for routine monitoring of plasma concentrations are available. On initiation of treatment, plasma therapy concentrations should be measured weekly until stabilisation is achieved, then weekly for one month and at monthly intervals thereafter.

Additional measurements should be made if signs of lithium toxicity occur, on dosage alteration, development of significant intercurrent disease, signs of manic depressions or depressive relapse and if significant change in sodium or fluid intake occurs. More frequent monitoring is required if patients are receiving any drug treatment that affects renal clearance of lithium e.g. diuretics and NSAID (see sections 4.4 and 4.5). As bioavailability may vary between formulations, should a change of preparations be made, blood levels should be monitored weekly until restabilisation is achieved.

Toxic symptoms are usually associated with concentrations exceeding 1.5 mmol/l and levels above 1.5mmol/l should be avoided. In the event of toxicity, lithium should be withdrawn immediately.

Withdrawal

If lithium is to be discontinued for other reasons, particularly in cases of high doses the dose should be reduced gradually over a suitable period of time, e.g. 2 weeks, to prevent the risk of relapse.

Posology

Acute mania

Adults

Treatment should be initiated in hospital where regular monitoring of plasma lithium levels can be conducted. The dosage of Camcolit should be adjusted to produce a plasma lithium level between 0.6 and 1.0 mmol/l 12 hours after the last dose. The required plasma lithium level may be achieved in one of two ways but, whichever is adopted, regular estimations must be carried out to ensure maintenance of levels within the therapeutic range.

For consistent results it is essential that the blood samples for plasma lithium estimations are taken 12 hours after the last dose of lithium.

1. 1,000-1,500 mg of lithium carbonate are administered daily for the first five days. A blood sample for plasma lithium estimation is taken 12 hours after the last dose on the fifth day, and the dosage of Camcolit is adjusted to keep the plasma lithium level within the therapeutic range. Subsequently, regular plasma lithium estimations must be carried out and, where necessary, the dosage of Camcolit adjusted accordingly. The precise initial dose of lithium should be decided in the light of the age and weight of the patient; young patients often require a dose higher than average and older patients a lower dose.
2. A lithium clearance test is carried out and the initial dosage calculated from the results.Even when the initial dosage is calculated in this way, it is still desirable that plasma lithium levels should be determined at weekly intervals during the first three weeks of treatment, and any necessary adjustments to dosage made as a result of the levels actually obtained.

Most of the above applies in the treatment of hypomania as well as mania, but the patient (if not too ill) can be started on treatment as an outpatient provided that facilities for regular plasma lithium monitoring are available, and assays are initiated within one week.

Prophylaxis of recurrent affective disorders

Adults (Including unipolar mania & unipolar depressions and bipolar manicdepressive illness)

A low dose of 300-400 mg of lithium carbonate can be administered daily for the first seven days. A blood sample for plasma lithium estimation is then taken 12 hours after the last dose, and the dosage of Camcolit is adjusted to keep the plasma lithium level within the range of 0.4- 0.8 mmol/l.

Aggressive and self-mutilating behaviour

Adults

Dosage is at the lower end of the range for the treatment for manic depressive illness.

Special Populations

Elderly

Start treatment with a low dose.

Elderly patients often require lower lithium dosage to achieve therapeutic serum levels. As for prophylaxis above, but 12-hour lithium levels should be kept in the range of 0.4-0.7 mmol/l as toxic symptoms are likely with plasma concentrations above 1.0 mmol/l. Toxic symptoms are more likely at lower concentrations than in the general population.

Paediatric population

Camcolit should not be used in children.

Method of administration

For oral administration.

Lithium carbonate has a narrow therapeutic window. Symptoms of lithium overdose (Lithium intoxication) can therefore occur due to intercurrent illness, iatrogenic causes, and self poisoning.

Any overdose in a patient who has been taking chronic lithium therapy should be regarded as potentially serious.

Acute overdosage

A single acute overdose usually carries low risk and patients tend to show mild symptoms only, irrespective of their serum lithium concentration. However more severe symptoms may occur after a delay if lithium elimination is reduced because of renal impairment, particularly if a slow-release preparation has been taken. The fatal dose, in a single overdose, is probably over 5g.

Acute overdosage in patient on chronic lithium therapy

If an acute overdose has been taken by a patient on chronic lithium therapy, this can lead to serious toxicity occurring even after a modest overdose as the extravascular tissues are already saturated with lithium.

In patients with a raised lithium concentration, the risk of toxicity is greater in those with the following underlying medical conditions: hypertension; diabetes; congestive heart failure; chronic renal failure; schizophrenia; Addison’s disease.

Symptoms

The onset of symptoms may be delayed, with peak effects not occurring for as long as 24 hours, especially in patients who are not receiving chronic lithium therapy or following the use of a sustained release preparation.

Mild: Nausea, diarrhoea, blurred vision, polyuria, light headedness, fine resting tremor, muscular weakness and drowsiness.

Moderate: Increasing confusion, blackouts, fasciculation and increased deep tendon reflexes, myoclonic twitches and jerks, choreoathetoid movements, urinary or faecal incontinence, increasing restlessness followed by stupor. Hypernatraemia.

Severe: Coma, convulsions, cerebellar signs, cardiac dysrhythmias including sino-atrial block, sinus and junctional bradycardia and first-degree heart block. Hypotension or rarely hypertension, circulatory collapse and renal failure.

Management

There is no known antidote to lithium poisoning.

In the event of accumulation, lithium should be stopped and serum estimation should be carried out every 6 hours. Special attention must be given to the maintenance of fluid and electrolyte balance, and also adequate renal function. Forced diuresis or diuretics should not be used in any circumstances. Appropriate supportive care may include measures to control hypotension and convulsions.

All patients should be observed for a minimum of 24 hours. ECG should be monitored in symptomatic patients. Steps should be taken to correct hypotension.

Consider gastric lavage for non-sustained-release preparations if more than 4g has been ingested by an adult within one hour or definite ingestion of a significant amount by a child. Slow-release tablets do not disintegrate in the stomach and most are too large to pass up a lavage tube. Gut decontamination is not useful for chronic accumulation. Whole bowel irrigation may be helpful in patients ingesting large quantities of a slow-release preparation.

Note: Activated charcoal does not adsorb lithium.

Haemodialysis is the treatment of choice for severe poisoning and should be considered in all patients with marked neurological features. It is the most efficient method of lowering lithium concentrations rapidly but substantial rebound increases can be expected when dialysis is stopped, and prolonged, or repeated treatments may be required.

It should be considered also in acute, acute on chronic or chronic overdose in patients with severe symptoms regardless of serum lithium concentration; discuss with your local poisons service.

Note: Clinical improvement generally takes longer than reduction of serum lithium concentrations regardless of the method used.

3 years.

Do not store above 25°C. Keep the container tightly closed.

Keep out of the sight and reach of children.

Polypropylene containers containing 56, 100 or 500 film-coated tablets.

For hospital use only, screw-cap amber glass bottles containing 50 or 100 film-coated tablets.

Not all pack sizes may be marketed.

No special requirements.