An Early Phase 1 interventional study of Benzydamine Hydrochloride in Sore Throat and Postoperative Care, sponsored by KK Women's and Children's Hospital. Recruiting at 1 site in Singapore. Open to female participants aged 21 Years to 80 Years. Per ClinicalTrials.gov, last updated 2026-08-06.
Sponsored by KK Women's and Children's Hospital · Early Phase 1, Interventional, and Prevention
Postoperative sore throat (POST) after laryngeal mask airway (LMA) insertion is prevalent and unappealing. A significant cause of POST is mechanical injury to the airway mucosa during airway instrumentation, leading to mucosal injury and inflammation. The Difflam Forte Anti-Inflammatory Throat Spray (Difflam) contains benzydamine hydrochloride, a non-steroidal anti-inflammatory agent with topical analgesic properties. This study will randomize 106 women undergoing gynaecological surgery under general anaesthesia with LMA use at KK Women's and Children's Hospital (KKH) in 1:1 allocation ratio of study (Difflam spray) and control (usual practice; no intervention) groups. Demographic and intraoperative airway data collection will be conducted in perioperative period. Those allocated to study group will receive Difflam spray when awake in the post-anaesthesia care unit (PACU). The primary aim to determine if patients undergoing general anaesthesia with LMA use with the Difflam spray in PACU will have a lower incidence of POST in the immediate and 4 hours postoperative recovery period, as compared with those in the control group. Other outcome measures include the severity of pain of sore throat as measured by the visual analog scale, and incidence of side effects associated with the Difflam spray. This proposal will determine whether the use of Difflam spray is suitable to be implemented in local clinical setting and improve perioperative care.
Postoperative sore throat (POST) after laryngeal mask airway (LMA) insertion is common, with reported incidences being as high as 40 - 60%. This is in spite of ongoing efforts to address this pertinent issue, including utilization of updated iterations of LMA devices, reduction of LMA cuff pressure, etc.. POST is an independent predictor of patient dissatisfaction following general anaesthesia and should be investigated further.
The cause of POST is multifactorial, with various mechanisms at play. A significant cause of POST is mechanical injury to the airway mucosa during airway instrumentation, leading to mucosal injury and inflammation. While the application of topical lidocaine on airway mucosa after surgery for analgesic relief may seem to be a possible solution, this may however, increase the risk of aspiration due to diminished cough reflex and swallowing ability. On the other hand, mouth gargles with analgesics may not provide immediate relief for POST as they require much cooperation from the patient that proves to be challenging in the immediate postoperative period.
The Difflam Forte Anti-Inflammatory Throat Spray is an over-the-counter medication indicated for temporary relief of painful mouth and throat conditions. It contains benzydamine hydrochloride (BH) 3 mg/mL, a non-steroidal anti-inflammatory agent (NSAID), and is recommended for adults to spray 2 to 4 times to the affected throat every 1.5 to 3 hours as needed. The effectiveness of benzydramine on alleviating sore throat has been well established in modern medicine. However, a spray formulation of this medication has not been utilized for this purpose yet. With the spray formulation, patient cooperation will not be required for effective delivery of BH medication - a critical factor in view of patient drowsiness post operation.
226 studies on the registry are indexed under Pharyngitis; 35 are open to participants now.
This study's planned enrollment of 106 is below the median of 144 across 188 interventional studies indexed under Pharyngitis.
Browse Pharyngitis studies →KK Women's and Children's Hospital is the lead sponsor of 137 studies on the registry; 33 are open to participants now.
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Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
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Study group will receive Difflam spray by delivering 4 sprays to the posterior pharynx. Patients will be asked to swallow after each spray. Questionnaires will then be administered to the patients 10 minutes after administration of the intervention, and then 4 hours after for their pain scores and side effects, if any.
Drug: Benzydamine Hydrochloride
Patients will be asked to fill in questionnaires for their pain scores and side effects, if any.
The Difflam Forte Anti-Inflammatory Throat Spray (iNova Pharmaceuticals Pte Ltd, Singapore) is an over-the-counter medication indicated for temporary relief of painful mouth and throat conditions. It contains benzydamine hydrochloride (BH) 3 mg/mL, a non-steroidal anti-inflammatory agent (NSAID), and is recommended for adults to spray 2 to 4 times to the affected throat every 1.5 to 3 hours as needed.
Also known as: benzydamine hydrochloride 3 mg/mL, Difflam Forte Anti-Inflammatory Throat Spray
Postoperative sore throat
Presence of postoperative sore throat (POST) during the immediate and 4 hours postoperative recovery period. At these two time points patients will be asked whether they have sore throat; and answering 'yes' will be considered as 'POST present'.
Time frame: 1 day; from the immediate and 4 hours postoperative recovery period
Postoperative pain score
Pain score during the immediate and 4 hours postoperative recovery period after intervention (Visual analog scale 0-10) will be asked, with zero being no pain, and 10 being the worst pain possible.
Time frame: 1 day; from the immediate and 4 hours postoperative recovery period
Side effects
Presence of side effects during the immediate and 4 hours postoperative recovery period. At these two time points patients will be asked whether they have burning and/or stinging, dry mouth, cough, local numbness; and answering 'yes' will be considered as 'burning and/or stinging, dry mouth, cough, local numbness present'.
Time frame: 1 day; from the immediate and 4 hours postoperative recovery period
Plan to share: No — To be shared upon request
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Started Aug 2025 (actual). Primary completion is estimated for Dec 2026, 16 months after the start.
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Studies of the drug tested here: Benzydamine
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