subcutaneous lidocaine for cancer-related pain

Conditions: Cancer-related Pain

Summary: this study's primary objective is to test the hypothesis that a single infusion of subcutaneous lidocaine can cause a clinically useful reduction in cancer pain within 48 hours of infusion and lasting a minimum of 7 days. a clinically useful reduction in pain is defined by either a 2-point reduction (on a 0-10 scale) in the worst pain experienced over a 24-hour period, or a ≥30% reduction in 24-hour opioid requirement. we will use a composite endpoint of reduction in pain without increase in 24-hr opioid requirement or no decrease in pain with a ≥30% reduction in 24-hour opioid requirement.subjects will receive either lidocaine or placebo, followed at least 1 week later by the alternate agent.

ten mg/kg of lidocaine will be infused subcutaneously via a baxter infusor over a 5.5 hour period in ambulatory adult cancer patients with a worst pain score of at least 4 out of 10 despite therapy with at least one opioid plus appropriate oral adjuvant analgesic(s). a clinically useful reduction in pain is defined by either a 2-point reduction (on a 0-10 scale) in the worst pain experienced over a 24-hour period, or a ≥30% reduction in 24-hour opioid requirement. the secondary objectives are 1) to determine whether any significant toxicities occur as a result of the infusion. for this study significant toxicity is considered as any adverse event which either leads to the infusion being terminated, or which leads to medical intervention, such as prescribing of another medication or equivalent treatment, 2) to determine the effect of lidocaine infusion on qol parameters as measured by the patient outcome scale (pos) questionnaire and 3) to determine the duration of response to lidocaine infusion. subjects will fill out brief pain inventory (bpi), patient outcome scale (pos) periodically and medication logs daily while on study. on days of treatment the subjects will have vital sign monitoring every 15 minutes for the 1st hour and then periodically as set out in the protocol.

Eligibility criteria:
inclusion criteria: * male or female patients 18 years of age or older * in or outpatients referred to the bcca psmpc clinics with a diagnosis of cancer * subjects must have somatic, visceral or neuropathic pain related to cancer * pain intensity, measured by a worst pain score over the last 72 hours of ≥4 on a 0-10 numerical rating scale * must have tried at least one opioid medication without adequate response or with significant side-effects for at least one week * for those with neuropathic pain, must have also tried at least one adjuvant analgesic, such as a tricyclic (unless contraindicated) or an anticonvulsant without adequate response or with significant side-effects for at least one week * life expectancy of \> 3 months * must be able to communicate symptoms indicating potential toxicity of lidocaine * must have a competent caregiver in the home overnight after each infusion * must be willing to remain within 30 minutes of the cancer centre during each infusion exclusion criteria: * clinically significant cardiac disease, i.e, cardiac failure, atrial fibrillation with slow ventricular rate (\<60), any degree of heart block * new analgesic treatment initiated in time frame which might have effect within one week of study drug. * hyper or hypokalemia. * liver failure (bilirubin ≥ 25 umol/l). * renal failure (egfr \<50% of normal) * uncontrolled hypertension (\>160/90). * hypotension (systolic \< 90). * uncontrolled seizures. * planned initiation of chemotherapy, radiotherapy or bisphosphonates within 30 days prior to treatment with study drug. * received an investigational drug within 30 days prior to study. * history of allergy to lidocaine or other topical, local or infusional anesthetics.

Keywords: pain cancer lidocaine sodium channel blockers