Chloroquine for prolonged skin analgesia in rats

Ying Jen Chang, Kuo Sheng Liu, Jhi Joung Wang, Ching Hsia Hung, Yu Wen Chen

Research output: Contribution to journalArticlepeer-review


The purpose of this study was to investigate the ability of chloroquine and chloroquine in combination with vasoconstrictor epinephrine to act as a local anesthetic in skin analgesia. After subcutaneous injection of drugs in rats, the inhibition of the cutaneous trunci muscle reflex (CTMR) is designed for evaluation of the cutaneous analgesic effect. The analgesic effect of chloroquine was compared with that of bupivacaine or coadministration of chloroquine and epinephrine. Chloroquine produced exactly the same local anesthesia as bupivacaine did in a dose-dependent manner. On the ED50 (50 % effective dose) basis, the analgesic potency was chloroquine (4.81 [4.45–5.20] μmol) < bupivacaine (0.46 [0.40‒0.52] μmol) (p < 0.01). At every equipotent dose tested (ED25, ED50 and ED75), chloroquine had a longer duration of cutaneous analgesia than bupivacaine (p < 0.01). Epinephrine enhanced the potency and duration of chloroquine-induced cutaneous analgesia. We found that chloroquine and bupivacaine elicit dose-dependent cutaneous analgesia. Chloroquine is not as potent as bupivacaine, but acts as an infiltrative anesthetic for a longer duration of time and is more potent and effective when used in combination with epinephrine.

Original languageEnglish
Article number135233
JournalNeuroscience Letters
Publication statusPublished - 2020 Sep 14

All Science Journal Classification (ASJC) codes

  • Neuroscience(all)

Fingerprint Dive into the research topics of 'Chloroquine for prolonged skin analgesia in rats'. Together they form a unique fingerprint.

Cite this