If you have had hemithyroidectomy or isthmusectomy, then you do not need any other medications apart from pain relief.  You will need a blood test at 1 month and 3 months following your surgery to check on your thyroid function.  Up to 40% of people who have had hemithyroidectomy may develop hypothyroidism (low thyroid hormones) and will require thyroid replacement medications.  People who have had isthmusectomy will rarely develop hypothyroidism.
 
Everyone who has had total thyroidectomy or completion thyroidectomy will require thyroid hormone supplementation indefinitely.  This is most commonly in form of Thyroxine medications.  T3 medications are rarely used in New Zealand and so far medication containing T3 and T4 (thyroid hormones) are not available in New Zealand and they are not subsidized.  Everyone who is on Thyroxine supplementation will need to have her/his thyroid function test performed regularly.  In the beginning this may be monthly, but later on may be 3 monthly. 
 
There are some people who do much better on supplementation that has both T3 and T4.  The only way so far in New Zealand is if they have Thyroid Extract.  This is made from pig thyroid and contains slightly higher T3 concentration (20%) then what is normally concentration in human blood.  Also more often blood tests are required to insure adequate thyroid hormone levels in blood (monthly blood tests).  This medication is not subsidized and the cost depends on the dosage of the Thyroid Extract.  Patients still require doctors prescription.
 
I also prescribe prophylactic calcium supplementation following Total Thyroidectomy or Completion Thyroidectomy.  Post-operatively in these situations calcium levels may drop for two reasons.  Firstly, it’s because parathyroid glands that are involved in calcium metabolism may be injured or disturbed during the surgery as they are always close to thyroid gland.  Secondly, even in patients who did not have thyroid or parathyroid surgery, calcium levels drop day 2 or day 3 due to postoperative hormonal changes involved in diuresis (water excretion). Few people may also require addition of Vitamin D to keep the calcium levels normal (usually these people have low post-operative Parathyroid hormone, PTH, levels).  The calcium levels will be monitored weekly until the calcium with or without vitamin D supplementation is stopped.  Usually within 3-6 weeks.