Brief Answer:
Gradual tapering of doses of Lithium is advised to prevent relapse

Detailed Answer:
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Lithium is a mood stabiliser and you are taking the drug since last 22 years. Abrupt stoppage of drug will result in withdrawal symptoms and will also increases the risk of relapse. So to prevent the withdrawal syndrome gradual tapering of doses of lithium is advised.

It is advised that the doses should be reduced by 10% every week and then complete stoppage at about 8-10 weeks but that is practically not possible because different strengths are not available. I usually advise my patients to reduce the doses by 20-25% every 2 weeks and then complete stoppage at about 8-10 weeks. In the same manner doses of Lamotrigine can be increased by 25 mg every two weeks. As both drugs are of different class and different mechanism of action so we can't find equivalent doses of Lithium and Lamortrigine. But 150-200 mg of doses of Lamotrigine works best as per my opinion.

So you can start with reduction of doses to 300 mg (as 300 mg strengths of Lithium is available) after about first 2 weeks and then reducing the doses to 200 mg after next 2-3 weeks and then halving the tablet after using the dose for 3 more weeks and then stopping the drug, in the same manner increase the dose of Lamotrigine by 25 mg. This is what I advise to my patients, consult your psychiatrist for proper prescription of drugs.

This will prevent withdrawal symptoms and relapse of symptoms.

Thanks, hope this helps you. Please don't hesitate to ask again for any more uncleared doubts.

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