Changes in Organ-Body Weight Relationship After Withdrawal of Chronic Lithium Administration in Rabbits

Abstract

Background: There is widely increasing use of lithium in psychiatric patients. Its chronic use
has various side effects on the body. These effects are more severe if drug is withdrawn suddenly,
affecting not only body weight but also other organs of the body disturbing hypothalamichypophyseal axis.
Objective: To document changes in organ-body weight relationship after withdrawal of chronic
Lithium administration in rabbits
Material and Methods: Thirty adult male rabbits were divided into two groups, control and
experimental. Each group was further divided into three subgroups. Lithium Carbonate powder
34.2 mg per kg body weight was administered daily by oral route in the form of capsule for four
weeks to experimental group whereas control group was given empty capsules and normal diet.
Animal weight and serum lithium levels were measured at the beginning of the experiment and
thereafter checked weekly. After four weeks, one third of the animals in each group were
sacrificed and their liver, kidney, thyroid and pituitary were weighed to see the effect of drug.
Second and third groups were sacrificed one and two weeks after lithium withdrawal, respectively.
Results: The mean serum lithium levels gradually dropped after one week and significant fall
was seen after 2 weeks of withdrawal but it did not touch the baseline. After 4 weeks of lithium
consumption, hypothalamic-hypophyseal axis showed exaggerated response reflected by
statistically significant increase in thyroid weight and statistically significant fall in that of pituitary
along with decrease in weight of animal and kidney.
Conclusion
Abrupt withdrawal of drug set hypothalamic-hypophyseal axis at a new level as reflected by
increase in thyroid and pituitary weight. Weight gained by body might be on account of other
reasons.