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Drug Details

CAMCOLIT 250

• Drug Class Description
  antimanic agent
• Generic Name
  lithium carbonate
• Presentation
  White film coated tablets engraved "CAMCOLIT" around one face and having a breakline on the reverse. For oral administration.
• Description
  The active ingredient is Lithium Carbonate; 250mg/tablet
• Indications
  

  The treatment and prophylaxis of mania, manic depressive illness and recurrent depression, and the treatment of aggressive or self mutilating behaviour.

• Adult Dosage
  

  CAMCOLIT 250mg tablets are usually administered according to a twice daily regimen. When lithium levels have stabilised, a once daily regimen may be preferred.

  Dosage

  Lithium carbonate has a narrow therapeutic window. Regular monitoring of plasma lithium concentration is always obligatory when Lithium is used; 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. 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 In the event of toxicity, lithium should be withdrawn immediately.

  However if lithium is to be discontinued for other reasons the dose should be reduced gradually over a suitable period of time, e.g. 2 weeks, to prevent the risk of relapse.

  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 manic-depressive 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.

• Child Dosage
  

  Not recommended.

• Elderly Dosage
  

  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.

• Contra Indications
  

  • A history of hypersensitivity to lithium or any of the excipients.

  • Severely impaired renal function

  • Untreated or untreatable hypothyroidism.

  • Cardiac disease associated with rhythm disorder.

  • Low body sodium levels for example dehydrated patients, those on low sodium diets, or those with Addison's disease.

  • Breast feeding.

• Special Precautions
  

  Lithium carbonate has a narrow therapeutic window. The dose required for treatment must be titrated and adjusted on the basis of regular monitoring of serum concentration of lithium. Lithium therapy should not be initiated unless adequate facilities for routine monitoring of plasma concentrations are available.

  Elderly patients are particularly liable to lithium toxicity. Use with care as lithium excretion may also be reduced. They may also exhibit adverse reactions at serum levels ordinarily tolerated by younger patients.

  Lithium excretion is reduced in the presence of renal impairment. This increases the risk of toxicity. Lithium is contra-indicated in patients with severe renal impairment. If patients with mild or moderate renal impairment are being treated with lithium, serum levels should be closely monitored.

  Renal function should be monitored in patients with renal impairment, and in patients with polyuria and polydipsia.

  Before beginning a lithium treatment

  -It is important to ensure that renal function is evaluated

  -Cardiac function should be assessed especially in patients with cardiovascular disease.

  -Thyroid function should be evaluated. Patients should be euthyroid before initiation of lithium therapy.

  -Renal, cardiac and thyroid functions should be re-assessed periodically.

  Monitoring of blood lithium levels

  Serum concentration of lithium should be measured on a sample taken just prior to the time when a dose of lithium is due to be taken (i.e. at trough level 12 hours following the last dose).

  Toxic effects may be expected at serum-lithium concentrations of about 1.5 mmol/litre, although they can appear at lower concentrations. They call for immediate withdrawal of treatment and should always be considered very seriously

  Serum lithium concentrations should be monitored more frequently (revert to weekly monitoring) in the following circumstances:

  - Dosage alteration or change of lithium formulation (bioavailability may differ)

  - Significant intercurrent disease

  - Intercurrent infection

  - Significant change in sodium intake

  - Significant change in fluid intake

  - Treatment with drugs altering renal clearance of lithium

  - Treatment with drugs likely to upset electrolyte balance.

  Patients should also be warned to report if polyuria or polydipsia develops. Episodes of nausea and vomiting or other conditions leading to salt/water depletion (including severe dieting) should also be reported. Patients should be advised to maintain their usual salt and fluid intake.

  Concomitant administration of antipsychotics should be avoided.

  Lithium should be stopped 24 hours before major surgery, but the normal dose can be continued for minor surgery if fluids and electrolytes are carefully monitored

  Warnings to be given to patients about signs and symptoms of toxicity

  Clear instructions regarding the symptoms of impending toxicity should be given by the doctor to all patients receiving long-term lithium therapy and advice given for the need for urgency in seeking medical assistance if these symptoms appear.

• Interactions
  

  Interactions may occur as a result of increased or decreased lithium levels, or may act through other mechanisms, the most important being neurotoxicity which may occur at therapeutic levels when other drugs which act centrally on the CNS are taken concurrently.

  Interactions which increase lithium concentrations

  Co-administration of the following drugs with lithium may lead to increased lithium concentrations and a risk of toxicity:

  • any drug which may cause renal impairment has the potential to cause lithium levels to rise, thereby causing toxicity. If the use of the drug is unavoidable, carefully monitor lithium blood level and adapt dosage as necessary.

  • antibiotics (metronidazole, tetracyclines, co-trimoxazole, trimethoprim), N.B. Toxic symptoms may also occur at low or normal levels when used in conjunction with co-trimoxazole or trimethoprim. non-steroidal anti-inflammatory drugs (including selective cyclo-oxygenase (COX) II inhibitors.

  • drugs affecting the renin angiotensin system (ACE inhibitors, Angiotensin II receptor antagonists).

  • Diuretics (including herbal preparations). In addition to the effects noted above, thiazide diuretics show a paradoxical antidiuretic effect resulting in possible water retention and lithium intoxication. Loop diuretics (furosemide and bumetanide, seem less likely to cause lithium retention, although caution is warranted.

  • Other drugs affecting electrolyte balance, e.g. steroids, may alter lithium excretion and should therefore be avoided.

  Interactions which decrease serum lithium concentrations:

  Co-administration of the following drugs with lithium may lead to decreased lithium concentrations and a risk of loss of efficacy:

  • xanthine derivatives (e.g. theophylline, caffeine).

  • products containing large quantities of sodium e.g. sodium bicarbonate.

  • carbonic anhydrase inhibitors.

  • Urea.

  Interactions which may not be associated with increased or reduced lithium levels:

  Concomitant use of the following drugs may precipitate symptoms of toxicity when the lithium level is within the normal range.

  • antipsychotics, including the atypical antipsychotics olanzapine, clozapine and haloperidol at high doses.

  • carbamazepine

  • phenytoin

  • methyldopa

  • clonazepam

  • tricyclic and tetracyclic antidepressants

  • calcium channel blockers. These drugs may cause neurotoxic reactions at therapeutic levels.

  • neuromuscular blocking agents. Lithium may cause neurotoxic reactions at therapeutic lithium levels.

  Selective serotonin re-uptake inhibitors (SSRIs): Concurrent use with lithium may precipitate a serotonergic syndrome.

  Non-steroidal anti-inflammatory drugs including COX II inhibitors: monitor serum lithium concentrations more frequently if NSAID therapy is initiated or discontinued

  Triptans: lithium toxicity reported suggestive of serotonin syndrome.

  Drugs which prolong the QT interval

  Lithium can cause an increase in the QTc interval, particularly at higher blood levels. Therefore concurrent use of drugs which have a risk of prolonging the QTc interval should be avoided, and consideration be made of other potential risk factors such as increasing age, female sex, congenital long QT syndrome, cardiac and thyroid disease and the following metabolic disturbances: hypocalcaemia, hypokalaemia, hypomagnesaemia.

  The following products have a high risk of causing QT prolongation and torsade de pointes: Class Ia antiarrhythmics , (disopyramide, procainamide, quinidine), Class III antiarrhythmics (amiodarone, sotalol), arsenic trioxide, artemisinin derivatives, dolasetron mesylate, mefloquine, intravenous erythromycin, amisulpride, haloperidol, pimozide, sertindole, terfenadine, thioridazine.

  ECG should be performed after initiation of treatment and at any point where the patient becomes symptomatic or when there are changes in disease or treatment which may increase the risk of interaction or arrhythmia.

  Non Drug Interactions:

  • Low sodium diet. Rapid reduction of sodium intake may cause raised lithium levels.

  • Intercurrent illness may cause lithium toxicity.

  Raised plasma levels of ADH may occur during treatment

• Adverse Drug Reactions
  

  Side effects are usually related to serum lithium concentrations and are less common in patients with plasma lithium concentrations below 1.0 mmol/l.

  Initial Therapy: fine tremor of the hands, polyuria and thirst may occur.

  Blood and Lymphatic system disorders: leucocytosis.

  Immune system disorders: increase in antinuclear antibodies.

  Endocrine disorders: disturbances of thyroid function including goitre, hypothyroidism and hyperthyroidism, hyperparathyroidism, parathyroid adenoma.

  Metabolism and nutrition disorders: hypercalcaemia, hypermagnesaemia, hyperglycaemia, anorexia, weight gain.

  Nervous system disorders: coma, pseudotumor cerebri, syndrome of irreversible lithium effectuated neurotoxicity (SILENT), encephalopathy, stupor, seizures, neuroleptic malignant syndrome, myasthenia gravis, serotonin syndrome, parkinsonism, extrapyramidal symptoms, ataxia, dizziness, memory impairment , mild cognitive impairment may occur during long term use, giddiness, nystagmus, slurred speech, vertigo, hyperactive deep tendon reflexes, dazed feeling, fine hand tremors.

  Eye Disorders: scotomata and blurred vision.

  Cardiac disorders: cardiac arrest, ventricular fibrillation, ventricular tachycardia, ventricular arrhythmias, Torsade de pointes, QT interval prolongation, cardiomyopathy, arrhythmia, bradycardia, sinus node dysfunction, ECG changes.

  Vascular disorders: Peripheral circulatory collapse, hypotension.

  Gastrointestinal disorders: gastritis, nausea, diarrhoea, vomiting, dry mouth, excessive salivation. Lithium salts have been implicated in dysgeusia.

  Skin and subcutaneous tissue disorders: Allergic rash, exacerbation of psoriasis, acneiform eruptions, alopecia, acne, papular skin disorder, folliculitis, pruritus, rash.

  Musculoskeletal and connective tissue disorders: muscle weakness.

  Renal and urinary disorders: symptoms of nephrogenic diabetes insipidus, impairment of renal function, permanent changes in the kidney, nephrotic syndrome, histological renal changes with interstitial fibrosis after long term treatment, polyuria, polydipsia

  Reproductive system and breast disorders: sexual dysfunction..

  General disorders and administration site conditions: sudden unexplained death, oedema, asthenia, lethargy, thirst, fatigue, and malaise can occur due to lithium toxicity.