Lithium

• Can exacerbate psoriasis
• Loads of other interactions
• Non-steroidal anti-inflammatory drugs (NSAIDs) decrease renal excretion of lithium, thus increasing plasma levels, leading to toxicity.
• Angiotensin-converting-enzyme inhibitors (ACE-I) and diuretics also increase the risk of lithium toxicity due to renal dysfunction. Therefore, their use is contraindicated with lithium.
• Not protein bound or metabolised to bioavailability close to 100%