It is very important that your doctor check your or your child's progress at regular visits to make sure that this medicine is working properly. Blood and urine tests may be needed to check for unwanted side effects.
Using this medicine while you are pregnant can harm your unborn baby. Use an effective form of birth control to keep from getting pregnant. If you think you have become pregnant while using the medicine, tell your doctor right away.
Call your doctor right away if you have diarrhea, vomiting, drowsiness, muscle weakness, tremors, unsteadiness, or other problems with muscle control or coordination. These may be symptoms of lithium toxicity.
Make sure your doctor knows if you have a heart disorder called Brugada syndrome. Brugada syndrome can be life-threatening and requires immediate medical attention. Call your doctor or the emergency department right away if you have a fast, pounding, or uneven heartbeat, unexplained fainting, lightheadedness, or troubled breathing after using this medicine.
This medicine may cause pseudotumor cerebri (increased pressure in the brain). Call your doctor right away if you have blurred or double vision, dizziness, eye pain, severe headache, or nausea and vomiting.
Encephalopathic syndrome (brain problem) may occur in patients using this medicine together with a medicine to treat mental illness (eg, chlorpromazine [Thorazine®], clozapine [Clozaril®], fluphenazine [Prolixin®], haloperidol [Haldol®], perphenazine [Trilafon®], risperidone [Risperdal®], thioridazine [Mellaril®]). Check with your doctor right away if you have the following symptoms while using this medicine: fever, confusion, drowsiness, difficulty with speaking, uncontrolled body movements, and unusual tiredness or weakness.
Check with your doctor right away if you have anxiety, restlessness, a fast heartbeat, fever, sweating, muscle spasms, twitching, nausea, vomiting, diarrhea, or see or hear things that are not there. These may be symptoms of a serious condition called serotonin syndrome. Your risk may be higher if you also take certain other medicines that affect serotonin levels in your body.
This medicine may cause some people to become dizzy, drowsy, or less alert than they are normally. Do not drive or do anything else that could be dangerous until you know how this medicine affects you.
Use extra care in hot weather and during activities that cause you to sweat heavily, such as hot baths, saunas, or exercising. If you have an infection or illness that causes heavy sweating, vomiting, diarrhea, shakiness, or muscle weakness, check with your doctor right away. The loss of too much water and salt from your body could lead to serious side effects from this medicine.
Do not go on a diet to lose weight and do not make a major change in your diet without first checking with your doctor. Improper dieting could cause the loss of too much water and salt from your body and could lead to serious side effects from this medicine.
Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines and herbal (eg, St. John's wort) or vitamin supplements.