Pharmacokinetics of butorphanol tartrate administered from single-dose intranasal sprayer

Opioids: A Review of Pharmacokinetics and Pharmacodynamics in Neonates, Infants, and Children

Pain management in the pediatric population is complex for many reasons. Mild pain is usually managed quite well with oral acetaminophen or ibuprofen. Situations involving more severe pain often require the use of an opioid, which may be administered by many different routes, depending on clinical necessity. Acute and chronic disease states, as well as the constantly changing maturational process, produce unique challenges at every level of pediatrics in dosing and management of all medications, especially with regard to high-risk opioids. Although there has been significant progress in the understanding of opioid pharmacokinetics and pharmacodynamics in neonates, infants, children, and adolescents, somewhat limited data exist from which necessary information, concerning the safe and effective use of these agents, may be drawn. The evidence here provided is intended to be helpful in directing the practitioner to patient-specific reasons for preferring one opioid over another. As our knowledge of opioids and their effects has grown, it has become clear that older medications like codeine and meperidine (pethidine) have very limited use in pediatrics. This review provides pharmacokinetic and pharmacodynamic evidence on the currently available opioids: morphine, fentanyl (and derivatives), codeine, meperidine, oxycodone, hydrocodone, hydromorphone, methadone, buprenorphine, butorphanol, nalbuphine, pentazocin, ketobemidone, tramadol, piritramide, naloxone and naltrexone. Morphine, being the most studied opioid analgesic, is the standard against which all others are compared. Pharmacokinetic parameters of morphine that have been found in neonates, i.e., higher volume of distribution, immature metabolic processes that develop at various rates, elimination that is variable based on age and weight, as well as treated and untreated disease processes, are an example of all opioids in the population discussed in this review. Outside the premature and neonatal population, the use of opioids in infants, children, and adolescents quickly begins to resemble the established values found in adults. As such, the concerns (risks) of these medications become comparable to those seen in adults.

Butorphanol suppression of histamine itch is mediated by nucleus accumbens and septal nuclei: a pharmacological fMRI study

Opioid receptors in the central nervous system are important modulators of itch transmission. In this study, we examined the effect of mixed-action opioid butorphanol on histamine itch, cowhage itch and heat pain in healthy volunteers. Using functional MRI, we investigated significant changes in cerebral perfusion to identify the critical brain centers mediating the antipruritic effect of butorphanol. Butorphanol suppressed the itch induced experimentally with histamine, reduced the intensity of cowhage itch by approximately 35%, and did not affect heat pain sensitivity. In comparison with the placebo, butorphanol produced a bilateral deactivation of claustrum, insula and putamen, areas activated during itch processing. Analysis of cerebral perfusion patterns of brain processing of itch vs. itch inhibition under the effect of the drug, revealed that the reduction of cowhage itch by butorphanol was correlated with changes in cerebral perfusion in the midbrain, thalamus, S1, insula and cerebellum. The suppression of histamine itch by butorphanol was paralleled by the activation of nucleus accumbens and septal nuclei, structures expressing high levels of kappa opioid receptors. In conclusion, important relays of the mesolimbic circuit were involved in the inhibition of itch by butorphanol and could represent potential targets for the development of antipruritic therapy.

A response to the opioid overdose epidemic: naloxone nasal spray

Opioid overdose morbidity and mortality is recognized to have epidemic proportions. Medical and public health agencies are adopting opioid harm reduction strategies to reduce the morbidity and mortality associated with overdose. One strategy developed by emergency medical services and public health agencies is to deliver the opioid antidote naloxone injection intranasally to reverse the effects of opioids. Paramedics have used this route to quickly administer naloxone in a needle-free system and avoiding needle-stick injuries and contracting a blood-born pathogen disease such as hepatitis or human immunodeficiency virus. Public health officials advocate broader lay person access since civilians are likely witnesses or first responders to an opioid overdose in a time-acute setting. The barrier to greater use of naloxone is that a suitable and optimized needlefree drug delivery system is unavailable. The scientific basis for design and study of an intranasal naloxone product is described. Lessons from nasal delivery of opioid analgesics are applied to the consideration of naloxone nasal spray.

Analgesic efficacy of tramadol and butorphanol in mandibular third molar surgery: a comparative study

BACKGROUND

Butorphanol tartrate, a mixed synthetic agonistantagonist opioid analgesic has been used for management of postoperative pain in minor and major surgical procedures.(14,20) Tramadol hydrochloride is a centrally acting opioid which is effectively used in postoperative pain in various minor and major surgeries.

MATERIALS AND METHODS

Twenty subjects selected randomly received butorphanol tartrate 1 mg intramuscular and 20 subjects received tramadol hydrochloride 50 mg intramuscular after the removal of mandibular third molars. Time of injection, amount of anesthetic injected, duration of surgery, adverse effects were recorded.(21)

RESULTS

The mean amount of LA administered in butorphanol group was 2.6450 ml and in tramadol group was 2.640 ml respectively, the mean duration for surgery was 56.75 and 53.5 minutes for butorphanol and tramadol groups respectively which was statistically not significant. Pain assessment was done with VAS which showed mean of 19.2 and 15.5 mm (p = 0.001) which was significant for butorphanol and tramadol respectively after 12 hours. The mean time for rescue medication requirement was 5.9 hours (for tramadol) and 8.4 hours (for butorphanol). Effective analgesic activity was seen by butorphanol 1 mg intramuscular then tramadol 50 mg.

CONCLUSION

Butorphanol 1 mg was more effective than tramadol 50 mg in respect to postoperative analgesia.

Intranasal drug delivery: an efficient and non-invasive route for systemic administration: focus on opioids

Intranasal administration is a non-invasive route for drug delivery, which is widely used for the local treatment of rhinitis or nasal polyposis. Since drugs can be absorbed into the systemic circulation through the nasal mucosa, this route may also be used in a range of acute or chronic conditions requiring considerable systemic exposure. Indeed, it offers advantages such as ease of administration, rapid onset of action, and avoidance of first-pass metabolism, which consequently offers for example an interesting alternative to intravenous, subcutaneous, oral transmucosal, oral or rectal administration in the management of pain with opioids. Given these indisputable interests, fentanyl-containing formulations have been recently approved and marketed for the treatment of breakthrough cancer pain. This review will outline the relevant aspects of the therapeutic interest and limits of intranasal delivery of drugs, with a special focus on opioids, together with an in-depth discussion of the physiological characteristics of the nasal cavity as well as physicochemical properties (lipophilicity, molecular weight, ionisation) and pharmaceutical factors (absorption enhancers, devices for application) that should be considered for the development of nasal drugs.

A review of the clinical pharmacokinetics of opioids, benzodiazepines, and antimigraine drugs delivered intranasally

BACKGROUND

Interest in the development of drug-delivery devices that might improve treatment compliance is growing. A dosage formulation that is easy to use, such as intranasal application with transmucosal absorption, may offer advantages compared with other routes of drug delivery. The literature concerning intranasal application is diffuse, with a large number of published studies on this topic. Some cerebroactive pharmaceuticals delivered intranasally might follow the pathway from the nose to the systemic circulation to the brain. To determine the suitability of these drugs for intranasal drug delivery, a systematic review was performed.

OBJECTIVE

The aim of this review was to compare the pharmacokinetic properties of intranasal, intravenous, and oral formulations in 3 classes of cerebroactive drugs that might be suitable for intranasal delivery-opioids, benzodiazepines, and antimigraine agents.

METHODS

A search of MEDLINE, PubMed, Cumulative Index of Nursing and Allied Health Literature, EMBASE, and Cochrane Database of Systematic Reviews (dates: 1964-April 2009) was conducted for pharmacokinetic studies of drugs that might be suitable for intranasal delivery. A comparison of pharmacokinetic data was made between these 3 routes of administration.

RESULTS

A total of 45 studies were included in this review. Most of the opioids formulated as an intranasal spray reached a T(max) within 25 minutes. The bioavailability of intranasal opioids was high; in general, >50% compared with opioids administered intravenously. Intranasal benzodiazepines had an overall T(max) that varied from 10 to 25 minutes, and bioavailability was between 38% and 98%. T(max) for most intranasal antimigraine drugs varied from 25 to 90 minutes. Intranasal bioavailability varied from 5% to 40%.

CONCLUSIONS

This review found that intranasal administration of all 3 classes of drugs was suitable for indications of rapid delivery, and that the pharmacokinetic properties differed between the intranasal, oral, and intravenous formulations (intravenous > intranasal > oral).

Bioavailability of intranasal butorphanol administered from a single-dose sprayer

PURPOSE

The bioavailability and tolerability of single doses of intranasal butorphanol tartrate using a single-dose, metered sprayer were studied.

METHODS

In this open-label, randomized, three-way crossover study, 24 healthy volunteers received three treatments: (1) 2 mg of i.v. butorphanol (treatment A), (2) 2 mg of intranasal butorphanol (treatment B), and (3) 1 mg of intranasal butorphanol (treatment C). The three treatments received by each subject were separated by six-day washout periods. Venous blood samples (10 mL each) were obtained from an indwelling catheter at 0 (predose), 5, 10, 15,20,30, and 45 minutes and 1,2,3,4,6,8, 12, and 16 hours after butorphanol administration. Pharmacokinetic parameters were determined using standard noncompartmental methods with log-linear least-squares regression analysis to determine the elimination-rate constants.

RESULTS

Intranasal butorphanol 1 and 2 mg administered using unit dose sprayers had a mean bioavailability of approximately 80%, which is higher than the percentage reported with the commercially available multidose product (61-69%). The absorption of intranasal butorphanol was rapid, with a median time to reach maximum concentration of 20 minutes (range, 10-60 minutes). Elimination profiles were comparable among all treatments. There were no clinically significant changes in the results of physical examinations, nasal evaluations, or laboratory tests related to butorphanol treatment. Most adverse effects reported were mild to moderate and as expected for this drug.

CONCLUSION

Single-dose intranasal butorphanol was rapidly absorbed and had high absolute bioavailability in healthy volunteers.