Background: Excessive ingestion of caffeine can induce hypokalemia, which affects the neuromuscular system and can lead to paralysis.
Case: A 24-year-old woman, gravida 3, para 2-0-0-2 at 33 weeks' gestation presented with muscular paralysis and hypokalemia secondary to drinking 6 to 7 L of cola per day with little other oral intake. After potassium replacement and stopping caffeine ingestion, the symptoms resolved quickly.
Conclusion: The physiologic changes of pregnancy might potentiate the effect of caffeine on serum potassium concentration.