Abstract
David Grounds, The Melbourne Clinic, Melbourne, Australia:
In November 2000 I was referred a 21-year-old man who had suffered two manic attacks, the first being in March 2000 and the second not long after – when he relapsed because of compliance problems. Since his discharge in May 2000, he had been taking lithium carbonate and olanzapine. His serum lithium levels were within the therapeutic range, being 0.9 mmol/L in September 2000.
In addition to side-effects of tiredness, ‘flatness’, and weight gain, which could be accounted for by the olanzapine medication, his main complaint was of incoordination in fast bowling. He is a keen cricketer and belonged to one of the lower grades of a metropolitan cricket club. He said that he had bowled more wides than straight balls since resuming cricket after his discharge.
There have been reports of disturbance of neuromuscular function in patients taking lithium and I suspected that was the most likely cause. His serum lithium was 1.0 and I reduced the dose to effect a lithium level of 0.6, which resulted in improvement, but he was still bowling a couple of wides an over. Cessation of olanzapine did not have any benefit and I then changed his mood stabiliser to Epilim (Sanofi; Sydney, Australia) at the end of December. His bowling gradually improved, and 4 weeks later he was back playing in the team.
In March 2001 I had a further report from a patient. A 71-year-old married woman with recurrent depression had lithium added to her trimipramine regimen in January 2000. Her serum levels since that time have either been 0.4 mmol/L or 0.5 mmol/L. She came for a follow-up consultation on the 6 March 2001 and informed me that she had decided to cease the lithium because she was not able to serve properly when playing tennis, and believed this had only been a problem while she was on the lithium. To support her contention, 2 weeks after she ceased the lithium, her serving ability was back to normal.
My two patients made the connection between lithium and their muscular incoordination, but some may not. It would be worthwhile for psychiatrists to keep in mind this side-effect and to enquire about similar difficulties.