Butorphanol pharmacokinetics

Butorphanol pharmacokinetics in the elderly differ from younger patients. 

Pharmacokinetic properties Butorphanol (Vachharajani et al., 1997) is rapidly inactivated by first pass metabolism in the gut. Intramuscular and nasal administration induces a peak effect between 0.5-1 hr and a duration of action of about 3 h, corresponding to the plasma half-life time of the compound. Butorphanol has a plasma protein binding of about 80%, metabolic inactivation includes hydroxylation,... 

Vachharajani, N.N., Shyu, W.C., Greene, D.S., Barbhaiya, R.H. The pharmacokinetics of butorphanol and its metabolites at steady state following nasal administration in humans, Biopharm. Drug Dispos. 1997, 18, 191-202. 

Butorphanol, an analog of buprenorphine, showed a nasal bioavailability of 70% and also a much lower Tmax after nasal absorption as compared with the sublingual and buccal routes [115]. Lindhardt et al. [106] compared buprenorphine formulated in 30% PEG-300 in sheep with that of the 5% dextrose formulation mentioned earlier. A unit-dose Pfeiffer device was again used to administer the formulation. It was found that nasal bioavailability in sheep was about 70% when buprenorphine was formulated in PEG-300 and approximately 89% when it was formulated with 5% dextrose. The rate of absorption was reported to be very fast, with a Tmax of 10 min the Cmax was found to be 37 and 48ng/mL for PEG-300 and dextrose, respectively. In sheep, the pharmacokinetics of buprenorphine showed a two-compartment model as compared to a three-compartment model in humans. 

Pharmacokinetics and adverse effects of butorphanol administered by single intravenous injection or continuous intravenous infusion in horses. American Journal of Veterinary Research 62 183-189 Sharrock A G 1982 Reversai of drug-induced priapism in a gelding by medication. Australian Veterinary Journal 58 39-40... 

Gillis JC, Benfield P, Goa KL. Transnasal butorphanol. A review of its pharmacodynamic and pharmacokinetic properties, and therapeutic potential in acute pain management. Drugs 1995 Jul 50(1) 157-175. 

Vachharajani NN, Sh3ni WC, Barbhaiya RH. Pharmacokinetic interaction between butorphanol nasal spray and oral metoclopramide in healdiy women. J Clin Pharmacol (1997) 37,979-85. 

The pharmacokinetics of intranasal butorphanol 1 mg every 6 hours and oral cimetidine 300 mg every 6 hours for 4 days were not significantly altered by concurrent use in 16 healthy subjects, except for a moderate increase in the elimination half-life of cimetidine. ... 

No pharmacokinetic interactions or change in adverse effeets were found to oeeur between single 1-mg doses of butorphanol tartrate nasal spray and a 6-mg subeutaneous dose of sumatriptan sueeinate in 24 healthy subjects. It was concluded that concurrent use during aeute migraine attacks need not be avoided. ... 

Srinivas NR, Shyu WC, Upmalis D, Lee JS, Barbhaiya RH. Lack of pharmacokinetic interaction between butorphanol tartrate nasal spray and sumatriptan succinate. J Clin Pharmacol (1995)35,432-7. 

Vachharajani NN, Shyu W-C, Nichola PS, Boulton DW. A pharmacokinetic interaction study between butorphanol and sumatriptan nasal sprays in healthy subjects importance of the timing of butorphanol administration. Cephalalgia (2002) 22,282-7. 

Vaughan, D.E., Pharmacokinetics of Albuterol and Butorphanol Administered Intravenously and via a Buccal Patch. 2003, Texas A M University, College Station, TX. 

H. K. Knych, H. C. Casbeer, D. S. McKemie and R. M. Arthur, Pharmacokinetics and pharmacodynamics of butorphanol following intravenous administration to the horse, J. Vet. Pharmacol. Ther., 2012, e-pub ahead of print. 

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