Its analgesic potency is essentially equivalent to that of morphine on a milligram basis, which is based on relative potency studies using intramuscular administration (Beaver et al. 1978). Oral administered nalbuphine is reported to be three times more potent than codeine (Okun et al. 1982). Clinical trials studied single dose experimental oral immediate release nalbuphine tablets for analgesic efficacy over a four- to six-hour time period following administration. Nalbuphine in the 15 to 60 mg range had similar analgesic effects to immediate release codeine in the 30 to 60 mg range (Kantor et al. 1984; Sunshine et al. 1983). Schmidt et al. (1985) reviewed the preclinical pharmacology of nalbuphine and reported comparative data relative to other types of opioid compounds. The authors point out that the nalbuphine moiety is approximately ten times more pharmacologically potent than the mixed opioid agonist/antagonist butorphanol on an "antagonist index" scale which quantitates the drugs ability to act both as an analgesic (via opioid KOR agonism) as well as a MOR antagonist. The opioid antagonist activity of nalbuphine is one-fourth as potent as nalorphine and 10 times that of pentazocine. Pharmacokinetics
The onset of action of nalbuphine occurs within 2 to 3 minutes after intravenous administration, and in less than 15 minutes following subcutaneous or intramuscular injection. The elimination half-life of nalbuphine is approximately 5 hours on average and in clinical studies the duration of analgesic activity has been reported to range from 3 to 6 hours. Chemistry
Nalbuphine is a derivative of morphine and is also known as N-cyclobutylmethyl-14-hydroxydihydronormorphine.
Nalbuphine, sold under the brand names Nubain among others, is an opioid analgesic which is used in the treatment of pain. It is given by injection into a vein, muscle, or fat.Side effects of nalbuphine include sedation, sweatiness, clamminess, nausea, vomiting, dizziness, vertigo, dry mouth, and headache. Unlike other opioids, it has little to no capacity for euphoria or respiratory depression. It also has little to no incidence of dysphoria, dissociation, hallucinations, and related side effects at typical therapeutic doses. Nalbuphine is a mixed agonist/antagonist opioid modulator. Specifically, it acts as a moderate-efficacy partial agonist or antagonist of the μ-opioid receptor (MOR) and as a high-efficacy partial agonist of the κ-opioid receptor (KOR), whereas it has relatively low affinity for the δ-opioid receptor (DOR) and sigma receptors.Nalbuphine was patented in 1963 and was introduced for medical use in the United States in 1979. It is marketed in many countries throughout the world. Medical uses
Nalbuphine is indicated for the relief of moderate to severe pain. It can also be used as a supplement to balanced anesthesia, for preoperative and postoperative analgesia, and for obstetrical analgesia during labor and delivery. However, a 2014 Cochrane Systematic Review concluded that from the included studies, there was limited evidence to demonstrate that "0.1 to 0.3mg/kg nalbuphine compared to placebo might be an effective postoperative analgesic" for pain treatment in children.