Nitrofurantoin

Nitrofurantoin has the following interaction information:

Magnesium Salts (oral)	absorption of nitrofurantoin reduced by oral magnesium salts (as magnesium trisilicate)
Probenecid	excretion of nitrofurantoin reduced by probenecid (increased risk of side-effects)
Sulfinpyrazone	excretion of nitrofurantoin reduced by sulfinpyrazone (increased risk of toxicity)

Nitrofurantoin belongs to Antibacterials and will have the following interactions:

Oestrogens	antibacterials that do not induce liver enzymes possibly reduce contraceptive effect of oestrogens (risk probably small, see section 7.3.1)	Interactions of combined oral contraceptives may also apply to combined contraceptive patches
Typhoid Vaccine (oral)	antibacterials inactivate oral typhoid vaccine –see under Typhoid vaccines, section