Difflam is generally well-tolerated and adverse effects are minor. The following adverse reactions have been reported after use of benzydamine HCl in solution form:
Local Adverse Reactions: The most commonly reported reaction is oral numbness (2.6%). Occasional burning or stinging sensation may occur and has been reported in 1.4% of treated cases. Other local adverse effects were less common and included dryness or thirst (0.2%), tingling (0.2%), warm feeling in mouth and altered sense of taste (<0.1%).
Systemic Adverse Reactions: These were very uncommon and never of a serious nature. They consisted mainly of nausea, vomiting, retching, gastrointestinal disorders (0.4%), dizziness (0.1%), headache and drowsiness (<0.1%).
Hypersensitivity reactions occur very rarely, but may be associated with pruritus, rash, urticaria, photodermatitis and occasionally, laryngospasm and bronchospasm.
The most common adverse reactions associated with chlorhexidine gluconate oral rinses are increased staining of teeth and other oral surfaces, increase in calculus formation and alteration in taste perception. Chlorhexidine tooth staining is harmless and can be minimized by thorough brushing of teeth before administration. No serious systemic adverse reactions associated with its use have been observed in clinical testing.