Topical Analgesia Post-Haemorrhoidectomy

A Prospective, Multicentre, Double-Blinded Randomised Controlled Trial Comparing Topical Metronidazole, Diltiazem and Lidocaine on Post-Operative Pain Following Excisional Haemorrhoidectomy

Symptomatic haemorrhoids, or piles, have significant effects on quality of life. The treatment for advanced disease is surgical excision (haemorrhoidectomy) which is extremely effective. However, pain following haemorrhoidectomy is known by all to be a miserable experience and current treatment is not very effective. We have formulated a new cream treatment which targets three theorised mechanisms of pain after haemorrhoidectomy. We will test the effectiveness of the treatments with a multi-centred randomised controlled factorial trial with four parallel double-blinded arms containing different combinations of the active agents. The outcomes include pain scores, amount of analgesia required and time to return to work. The results of our study could provide evidence of an effective treatment for post haemorrhoidectomy pain. The treatment may provide considerable benefit to patients undergoing this surgical procedure.

Study Design: This will be a patient-and-investigator blinded factorial randomised trial with four parallel groups. Participants in all four groups will be instructed to apply cream 3 times a day for 7 days after surgery. A standard analgesia prescription will be provided with laxatives as per routine care. Patients will be provided a questionnaire to complete and return on day 14.

Random Sequence Generation: Computer generated sequence allocating patients to a 1:1:1:1 ratio using permuted block randomisation in blocks of 12.

Allocation Concealment: This randomisation code will be seeded to the pharmacist to who will package and label the cream according to a code. The creams will be indistinguishable to which active ingredient they contain.

Assignment of intervention: Patients will be assigned in order according to the numbering of the cream tubes by the blinded investigator.

Data recording: Data will be recorded on Redcap database.

Inclusion Criteria:

• Age ≥16
• All patients undergoing excisional haemorrhoidectomy

Exclusion Criteria:

• Age <16,
• history of chronic pain,
• drug allergy or idiosyncracies to any actives or excipients in
• cream,
• breastfeeding,
• any medical history which is a contraindication to any of metronidazole, lidocaine, or diltiazem including including:
• sick sinus syndrome,
• atrioventricular block,
• hypotension,
• heart failure and bradycardia.
• concomitant medications which are contraindicated to metronidazole, lidocaine or diltiazem.
• patients already taking diltiazem.