Safety and efficacy of intranasal ketamine for acute postoperative pain

SummaryBackgroundSubanaesthetic doses of ketamine are analgesic. Intranasal administration offers a non-invasive route for systemic drug delivery. We evaluated the safety and analgesic efficacy of intranasal ketamine in treating moderate-to-severe, acute postoperative pain in the molar extraction model.MethodsIntranasal ketamine (10 mg, 30 mg, and 50 mg) and placebo were evaluated in a randomised, double-blind, single-dose, parallel study in 40 patients undergoing removal of 2–4 impacted third molars. Analgesic efficacy was assessed over a 3 h period following drug administration. Safety was evaluated through adverse event reporting, vital signs, pulse oximetry, nasal assessments, and a standard dissociative side effects questionnaire.ResultsKetamine delivered intranasally was well tolerated. Statistically significant analgesia, superior to placebo, was observed with the highest dose tested, 50 mg, over a 3 h period. Rapid onset of analgesia was reported (<10 min), and meaningful pain relief was achieved within 15 min of the 50 mg dose. The majority of adverse events were mild/weak and transient. No untoward effects were observed on vital signs, pulse oximetry, and nasal examination. At the doses tested, no significant dissociative effects were evident using the Side Effects Rating Scale for Dissociative Anaesthetics.ConclusionIntranasal ketamine may offer a safe, nonopioid, well-tolerated, needle-free analgesic with efficacy in moderate-to-severe acute pain.