Lithium affects the flow of sodium through nerve and muscle cells in the body. Sodium affects excitation or mania.
Lithium is an element. It gets its name from “lithos,” the Greek word for stone, because it is present in trace amounts in virtually all rocks. Lithium works with other elements, drugs, enzymes, hormones, vitamins, and growth factors in the body in many different ways. People use it for medicine.
Lithium is used for mental illnesses, including bipolar disorder, depression, and schizophrenia.
How does it work?
Exactly how lithium works is unknown, but it might help mental disorders by increasing the activity of chemical messengers in the brain.
What are the common side effects?
Many people get no side effects at all. The list here is to tell you what occasionally happens to some people. (If you have psoriasis or kidney problems, however, put it at the bottom of your list of options; it can make these worse).
Because lithium is very similar to sodium (a "salt"), taking lithium is like taking small salt tablets: it makes you thirsty. If you don’t drink more water than usual, you can have dry mouth. But when you do drink more, you will also urinate more. During the day this is usually not a problem, but some people have to get up at night to urinate when they did not need to before. Most people taking lithium will notice these effects somewhat, more so at higher doses.
Some people can have nausea from lithium. The slow-release versions (Lithobid, Eskalith) are much less likely to cause this but can cost you more (not generic). After you have been taking lithium without nausea, becoming nauseous is a dangerous sign: your level may have become too high; get a lithium level if this does not get better, or if you get other lithium side effects.
As the dose and blood level go up, some other side effects can occur. Tremor (usually seen as shaky hands) is common. It can often be controlled with low doses of "propanolol", a blood pressure medication, if you and your doctor decide to continue lithium at this dose.
Weight gain can occur with lithium. At first almost everyone will gain a few pounds as their body hangs on to more water (salt effect). Some people can continue to gain weight, though. This is much less of a problem with lithium than with valproate, both in how often it happens and how much weight is gained. Usually at this point we will switch medications, but some people can control the weight issue with regular exercise, wise eating, and avoiding alcohol entirely -- all good health habits anyway.
Some people can have "edema", when your body has too much water, which shows up as ankle swelling or feeling "bloated". High doses can cause dry skin. At higher doses, loose stool or even diarrhea are frequently noted. Most of the other side effects you will see reported are uncommon.
Too high a dose causes nausea, feeling very unsteady or "wobbly", slurring of speech, and confusion. If you notice these, call the on-call physician (she or he may arrange for a lithium blood test, and may lower your dose until the test shows what to do). It is dangerous to continue lithium if you have these side effects.
Are there any serious side effects?
Very high lithium levels, such as in overdose or continuing to take too much, can be fatal or cause kidney damage or other problems. Rarely a person can get very high levels when taking the right dose: this usually involves interactions with another medicine such as ibuprofen (Motrin, Advil) or blood pressure medications; or becoming severely dehydrated (losing fluids through vomiting and/or diarrhea is the most common; if you are sick, taking no lithium until you can drink--and keep!-- plenty of water can avoid this); or making a mistake with the dosing.
Lithium can decrease thyroid hormone in about one out of 10 people taking lithium (common). The gland is generally okay and recovers its usual function if lithium is stopped; the only exception to this may be in families where there are relatives with thyroid problems. Thyroid levels need to be checked at least once a year while on lithium, but several times in the first year. (Some references recommend routine checks twice a year, and a few even more often than that; this is a matter for discussion with your doctor). We usually check your lithium level as well at that time.
Long-term lithium treatment, for a decade or two, can lead to a steady lowering in kidney function. The higher the dose, the greater will be this risk. It is routine to monitor kidney function while people are taking lithium, and this is important to insure long-term safety. I've had two patients who had done so well on lithium, for decades, that we were reluctant to switch treatment, even as their kidney test slowly worsened. I now realize I was too slow to get them off it, and as a result they have to get up several times a night to urinate (this condition is called diabetes insipidus; unrelated, except in frequent urination, to the diabetes you hear about all the time, which is a sugar problem--diabetes mellitus). Make sure your doctor is watching this kidney test, called "creatinine". When your creatinine goes over 1.0 or 1.2, it's time to have a discussion about switching medications.
In addition to the slow decrease in kidney function, there is a risk of "kidney failure", requiring dialysis. In most cases this has been associated with "lithium toxicity", that is, getting much too high a blood level of lithium. As you can see, there are many reasons to be careful with lithium, especially if your blood levels are in the range of 1.0 or higher.
What about pregnancy?
This medication can definitely cause abnormalities in unborn children. Becoming pregnant while taking any medication for bipolar disorder is a tricky issue that requires discussion with a specialist in this disorder. Tell your doctor how you will avoid becoming pregnant.
DIRECTIONS TO FOLLOW
1. Take the lithium dosage your doctor has prescribed especially for you. Taking less
lithium than prescribed may not be effective. Taking more can make you sick.
2. D0 NOT change your dosage if you should experience mood swinging. Consult your doctor.
3. A good habit to get into is taking your lithium with meals, unless your doctor has advised otherwise; your dosage is remembered more easily. You are less likely to feel nauseated if lithium is taken with some food in your stomach.
4. Maintain a diet with a normal amount of fluids and salt.
5. Do NOT take your morning dosage the day of your blood test, until after the test. If you forget and take your dose do not have your blood level test done that day.
6. Discuss with your doctor a method for making up missed dosages.
7. Most, but not all, other drugs can be safely taken with lithium. You should always consult your doctor before taking other drugs in the presence of lithium.
8. Lithium is an "insurance policy" against recurring episodes of manic depression. Do not make the mistake of not taking your lithium just because you feel better. You will be depriving yourself of the full benefits of lithium.
9. Inform your nearest relative or closest friend that you are being treated with lithium. We suggest that you read over these guidelines together and discuss them.