Intrarectal Lidocaine Gel Used Alone for Procedures
Intrarectal lidocaine gel alone can be used effectively for transrectal ultrasound-guided prostate biopsies, with multiple randomized trials demonstrating significant pain reduction compared to placebo or no treatment, though its efficacy is debated and appears most beneficial for probe insertion discomfort rather than the biopsy itself. 1
Evidence from Randomized Controlled Trials
Studies Supporting Efficacy
A 2000 randomized trial (n=50) from Emory University demonstrated that 10 cc of 2% intrarectal lidocaine gel administered 10 minutes before transrectal prostate biopsy significantly reduced median pain scores from 5 (control group) to 2 (lidocaine group), with p=0.00001. 1
A 2009 study (n=147) specifically evaluated younger patients (<65 years) and found that intrarectal lidocaine cream 2% significantly reduced anal discomfort during probe insertion, with mean pain scores of 1.7 versus 5.7 in the control group receiving only lubricant gel. 2
A 2005 randomized trial (n=210) compared EMLA cream, 2.5% lidocaine gel, placebo, and no treatment, finding median pain scores of 3.8 for lidocaine gel versus 3.9 for placebo and 3.6 for no treatment, though EMLA cream performed better at 2.6. 3
Studies Showing No Benefit
A 2001 double-blind randomized trial (n=108) found no significant difference in pain scores between 2% intrarectal lidocaine gel and lubricant alone (28.3 mm versus 28.9 mm on visual analog scale, p=0.88). 4
This study notably found that younger age correlated negatively with pain tolerance (r=-0.27, p=0.005), but lidocaine provided no therapeutic benefit regardless of age. 4
When Lidocaine Gel Alone Provides Benefit
Intrarectal lidocaine gel appears most effective for reducing discomfort during probe insertion rather than during the actual biopsy procedure itself. 2
A 2007 study (n=203) that compared intrarectal lidocaine gel plus periprostatic block versus periprostatic block alone found that lidocaine gel provided significant additional analgesic effect during biopsy (p<0.01), suggesting it has additive but not standalone efficacy. 5
The gel may be particularly beneficial in younger patients who are more likely to undergo repeated biopsies and experience higher baseline discomfort. 2
Clinical Context and Limitations
The evidence is mixed regarding intrarectal lidocaine gel as a sole anesthetic agent, with some high-quality randomized trials showing benefit and others showing none. 4, 1
When used alone, lidocaine gel does not provide the same level of analgesia as periprostatic nerve blocks, which are considered superior for the biopsy procedure itself. 5
The American Academy of Dermatology guidelines do not specifically address intrarectal procedures, focusing instead on dermatologic applications where topical anesthesia is recommended for minor procedures but infiltrative anesthesia is preferred for larger incisions and deeper tissue manipulation. 6
Practical Recommendations
For transrectal ultrasound-guided prostate biopsies, intrarectal lidocaine gel can be used alone as a simple, safe method, particularly when periprostatic blocks are not feasible or desired. 1
Administer 10 cc of 2% lidocaine gel intrarectally approximately 10 minutes before the procedure to allow adequate mucosal absorption. 1
Consider combining intrarectal lidocaine gel with periprostatic nerve blocks for optimal pain control, as this provides superior analgesia compared to either method alone. 5
Be aware that efficacy varies significantly between patients, and younger patients may require additional anesthetic measures despite lidocaine gel administration. 4, 2