AKT-4263

A 38-year-old man with known bipolar disorder is brought in by his mother because she has noticed that he has become drowsy over the past week and he has also been off balance, with diarrhoea and vomiting. He has a complicated past medical history including labile hypertension, bipolar disease and asthma and he is multi-medicated.

His oral medication list is:
– codeine
– lithium
– paracetamol
– quetiapine
– ramipril, and
– theophylline

He also takes inhalers for his asthma. His blood tests show elevated lithium levels of 1.5 mmol/L. Which of his medications is most likely to have interacted with the lithium, resulting in elevated levels?