Pharmacokinetics of the combination tablet of buprenorphine and naloxone.
The sublingual combination tablet formulation of buprenorphine and naloxone at a fixed dose ratio of 4:1 has been shown to be as effective as the tablet formulation containing only buprenorphine in treating opiate addiction. The addition of naloxone does not affect the efficacy of buprenorphine for two reasons: (1) naloxone is poorly absorbed sublingually relative to buprenorphine and (2) the half-life for buprenorphine is much longer than for naloxone (32 vs. 1 h for naloxone). The sublingual absorption of buprenorphine is rapid and the peak plasma concentration occurs 1 h after dosing. The plasma levels for naloxone are much lower and decline much more rapidly than those for buprenorphine. Increasing dose results in increasing plasma levels of buprenorphine, although this increase is not directly dose-proportional. There is a large inter-subject variability in plasma buprenorphine levels. Due to the large individual variability in opiate dependence level and the large variability in the pharmacokinetics (PK) of buprenorphine, the effective dose or effective plasma concentration is also quite variable. Doses must be titrated to a clinically effective level for individual patients.
Chiang
C Nora
CN
Division of Treatment Research and Development, National Institute on Drug Abuse, 6001 Executive Blvd, Bethesda, MD 20892, USA. nchiang@nih.gov
Hawks
Richard L
RL
D000286:Administration, Sublingual; D002047:Buprenorphine / Q000008:administration & dosage* / Q000097:blood / Q000493:pharmacokinetics*; D000069479:Buprenorphine, Naloxone Drug Combination; D004338:Drug Combinations; D006801:Humans; D009270:Naloxone / Q000008:administration & dosage* / Q000097:blood / Q000493:pharmacokinetics*; D009292:Narcotic Antagonists / Q000008:administration & dosage* / Q000097:blood / Q000493:pharmacokinetics*; D009293:Opioid-Related Disorders / Q000188:drug therapy / Q000378:metabolism; D013607:Tablets
D000069479:Buprenorphine, Naloxone Drug Combination; D004338:Drug Combinations; D009292:Narcotic Antagonists; D013607:Tablets; D009270:Naloxone; D002047:Buprenorphine