<p>Sodium bicarbonate: Increases toxicity of amphetamines, ephedrine, pseudoephedrine, flecainide, quinidine and quinine. Decreases effects of lithium, chlorpropamide and salicylates due to increased clearance. May affect the absorption of certain drugs due to raised intra-gastric pH. Sodium chloride: May affect serum concentrations of lithium.</p>