High caffeine intake may accelerate lithium clearance and affect treatment outcomes.

Caffeine may influence how lithium behaves in the body. Because caffeine has mild diuretic effects and can increase urine production, it changes how the kidneys clear lithium from the body. As a result, high caffeine intake may increase lithium clearance and reduce the lithium concentration in the blood.

Several clinical observations support this idea. In one case report, a 54-year-old man with bipolar disorder consumed large amounts of caffeine for two years. Each day, he would drink four Monster Energy cans, three cans of Coca-Cola, and three cups of coffee. During this period, his lithium blood levels dropped. When he reduced his coffee intake, lithium levels increased again, suggesting that caffeine affected how the drug was cleared from his body.

Similar patterns have been observed in other reports. In several patients, reducing or stopping caffeine intake caused lithium concentrations to rise. In a few cases, this increase led to side effects such as lithium tremor, which improved only after the lithium dose was reduced.

Because lithium has a narrow therapeutic window, these interactions are clinically important. Large or sudden changes in caffeine intake may lower lithium levels and reduce its effectiveness. Conversely, abruptly stopping caffeine may increase lithium levels and raise the risk of toxicity. 

For this reason, clinicians usually recommend keeping caffeine intake the same as it was before the start of the treatment. People taking lithium should consult a healthcare provider before making any changes in caffeine intake.

Products Containing Caffeine

Beverages, food, and medications can contain caffeine. Check if you know them all:

• Coffee.

• Black and green tea.

• Matcha.

• Dark chocolate.

• Energy drinks.

• Cocoa and tiramisu.

• Guarana seeds.

• Supplements.

• Medications such as Excedrin, Anacin, and Vanquish.

Where To Check Drug Interactions?

Visit this website to check possible interactions between caffeine, lithium, and other substances.

Read Next:

• Lithium as a Life-Saving Treatment for Bipolar Disorder

• Discover What Lower Doses of Lithium Do

• Lithium Could Save Seven Million Americans

Science Sources:

• What is a proper diet to go on with lithium?

• Can You Take Caffeine with Lithium?

• Sudden Reduction in Caffeine Intake Increases Serum Lithium Concentration to Supratherapeutic Level: A Case Report

• Lithium tremor and caffeine intake: two cases of drinking less and shaking more

• The impact of caffeine consumption on clinical symptoms in patients with bipolar disorder: A systematic review

• Lithium/caffeine interaction

• Low-caffeine green tea supplementation reduced lithium serum levels and the relative abundance of microbiota in women with obesity: A case study

• The caffeine contents of dietary supplements commonly purchased in the US: analysis of 53 products with caffeine-containing ingredients