SN instructed patient / caregiver regarding medication Levothyroxine. SN taught patient / caregiver that Levothyroxine is a replacement for a hormone that is normally produced by the thyroid gland to regulate the body's energy and metabolism. SN explained that Levothyroxine is given when the thyroid does not produce enough of this hormone on its own. SN explained that Levothyroxine treats hypothyroidism ( low thyroid hormone ). SN explained that Levothyroxine is also used to treat / prevent goiter. SN taught patient / caregiver about the side effects of this medication such as headache, insomnia, nervous or irritable feeling, fever, hot flashes, sweating, changes in your menstrual periods, appetite changes and weight changes. SN Instructed patient / caregiver to notify physician ( MD ) if experiencing persistent or worsening of side effects.