Nalbuphine Hydrochloride is a synthetic opioid analgesic, which binds with mu, kappa and delta receptor. Its analgesic potency is equivalent to Morphine on a milligram basis and 10 times more than that of Pentazocine but has lower side effects and less abuse potential than Morphine. The onset of action of Nalbuphine occurs within 2 to 3 minutes after intravenous administration and in less than 15 minutes following intramuscular injection. The plasma half-life of Nalbuphine is 5 hours and the duration of analgesic activity is 3 to 6 hours.

Pharmacology

Nalbuphine Hydrochloride is a synthetic potent analgesic. Its analgesic potency is essentially equivalent to that of morphine on a milligram basis. Receptor studies show that Nalbuphine binds to mu, kappa, and delta receptors, but not to sigma receptors. Nalbuphine is primarily a kappa agonist/partial mu antagonist analgesic.

Nalbuphine Hydrochloride is indicated for the relief of moderate to severe pain. It is used for relief of moderate to severe pain associated with myocardial infarction (MI). Nalbuphine Hydrochloride can also be used as a supplement to balanced anesthesia, for preoperative and postoperative analgesia, and for obstetrical analgesia during labor and delivery.

The usual recommended adult dose is 10 mg for a 70 kg individual, administered subcutaneously, intramuscularly or intravenously; this dose may be repeated every 3 to 6 hours as necessary. Dosage should be adjusted according to the severity of the pain, physical status of the patient, and other medications which the patient may be

receiving.

Moderate to severe pain: by intravenous or intramuscular injection 10-20 mg for 70 kg patient, adjusted as required; child up to 0.3 mg/kg repeated once or twice as necessary.

Preoperative anesthesia: by intravenous or intramuscular injection 0.1-0.2 mg/kg.

Obstetrical analgesia during labor & delivery: by intravenous injection 0.3-1 mg/kg over 10-15 minutes with maintenance doses of 0.25-0.5 mg/kg in single intravenous administration as required.

Intraoperative analgesia: by intravenous injection 0.25-0.5 mg/kg at 30 minutes intervals.

Myocardial infarction: By slow intravenous injection 10-20 mg, repeated after 30 minutes if necessary. Larger dose is required when used as supplement of anesthesia than that required for analgesia.

Children from 18 months to 15 years old: usually 0.2 mg/ kg body-weight, given preferably by intravenous or intramuscular injection. Maintenance doses may be given at intervals of 4 to 6 hours or the dose must be determined by the physician.

Known hypersensitivity to Nalbuphine Hydrochloride.

Generally Nalbuphine is well tolerated. However few side-effects like sedation, sweating, nausea, vomiting, dizziness, vertigo, dry mouth, headache, respiratory depression, dyspnea and asthma may be seen.

Overdose Effects

Sleepiness & mild dyspnea may occur due to overdose. The immediate intravenous administration of an opiate antagonist such as Naloxone or Nalmefene is a specific antidote. Oxygen, intravenous fluids, vasopressors and other supportive measures should be used as indicated

Caution should be taken in the following conditions: impaired respiration, impaired renal or hepatic function, billiary tract surgery, myocardial infarction and hypotension.

Pregnancy & Lactation

Pregnancy category B. The placental transfer of Nalbuphine is high and rapid. There are no well-controlled studies in pregnant women. This drug should be used during pregnancy only if clearly needed. Limited data suggest that Nalbuphine is excreted in maternal milk but only in a small amount (less than 1% of the administered dose) and with a clinically insignificant effect. Caution should be exercised when Nalbuphine is administered to a nursing woman.