<p><strong>Fucidic Acid</strong>: Synergistic action with antistaphylococcal penicillin. Antagonism with ciprofloxacin.<br />
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<strong>Betamethasone</strong>: Increased hyperglycaemia and hypokalaemia with thiazide diuretics. Increased incidence of peptic ulcer or Gl bleeding with concurrent NSAIDs admin. Response to anticoagulants altered. Dose of antidiabetics and antihypertensives needs to be increased. Decreases serum cone of salicylates and antimuscarinic agents.<br />
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<strong>Potentially Fatal</strong>: Reduced efficacy with concurrent use of carbamazepine, phenytoin, primidone, barbiturates and rifampicin. Enhanced effect in women taking oestrogens or oral contraceptives.</p>