Oral phenobarbital loading: a safe and effective method of withdrawing patients with headache from butalbital compounds.

Loder E, Biondi D.

Headache and Pain Management Program, The Spaulding Rehabilitation Hospital, Boston, Mass 02114, USA.

BACKGROUND: The overuse of short-acting barbiturate medications for the acute treatment of headache is a common problem in the United States. Most experts agree that withdrawal from these medications is necessary for subsequent headache treatment to be successful, yet there are few published articles outlining effective methods of drug withdrawal. OBJECTIVE: To evaluate the safety and effectiveness of phenobarbital loading for withdrawal from overuse of short-acting barbiturate compounds in inpatients with headache. DESIGN AND METHODS: We performed a retrospective chart review of 18 consecutive patients in an inpatient pain rehabilitation program who were withdrawn from overuse of butalbital-combination medications using a phenobarbital-loading protocol. RESULTS: Eighteen patients with headache hospitalized in an inpatient pain unit for withdrawal from overuse of combination butalbital preparations underwent a phenobarbital-loading protocol. Short-acting barbiturate medications were discontinued, and patients received 120 mg of oral phenobarbital until their score on a predetermined scale reached target levels, and the drug was then discontinued. All patients were effectively treated with no serious adverse events. The median number of doses required varied significantly, and could not be predicted by the patient's prior intake. CONCLUSIONS: Management of butalbital withdrawal can be simplified by using a phenobarbital-loading protocol, taking advantage of the natural tapering afforded by the drug's long half-life. This method possesses most of the characteristics of an ideal drug withdrawal program for patients with headache who are overusing medications.

Source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12940814&dopt=Abstract barbiturate Butalbital Fioricet





Suppression of cerebral metabolic rate for oxygen (CMRO2) by mild hypothermia compared with thiopental.

Nemoto EM, Klementavicius R, Melick JA, Yonas H.

Department of Anesthesiology and Critical Care Medicine, University of Pittsburgh School of Medicine, PA 15261, USA.

If the efficacy of hypothermia and barbiturates in ameliorating ischemic brain injury lies in reducing the cerebral metabolic rate of oxygen (CMRO2), the greater efficacy of mild hypothermia (34 degrees C) compared with barbiturates is inconsistent with the 15-20% reduction of CMRO2 caused by mild hypothermia compared with 50% caused by barbiturates. This paradox, we hypothesized, derives from the fact that whereas barbiturates lower CMRO2 associated with EEG activity or thiopental (TP)-suppressible CMRO2, not essential for cellular viability, hypothermia lowers CMRO2 associated with providing energy, i.e., adenosine triphosphate, to maintain transmembrane ion gradients or TP-nonsuppressible CMRO2, essential for neuronal viability. To test this hypothesis, we measured whole brain cerebral blood flow (CBF) and CMRO2 in two groups of rats mechanically ventilated with 70% N2O/30% O2 before and after TP-induced isoelectric EEG. In the normothermic group (n = 7), measurements were made at a brain temperature (Tb) of 38 degrees C, while in the hypothermic group (n = 7), they were made at 34 degrees C. In the normothermic group, TP-induced isoelectric EEG reduced CMRO2 by 50%, from 7.92 +/- 1.05 to 3.95 +/- 0.70 ml 100 g-1 min-1 (mean +/- = SD). Thus, at 38 degrees C, TP-suppressible and TP-nonsuppressible CMRO2 were both 50 +/- 4% of total CMRO2. In the hypothermic group, decreasing Tb from 38 to 34 degrees C caused a 17% decline in CMRO2, from 7.62 +/- 1.92 to 6.28 +/- 1.22 ml 100 g-1 min-1 (p > 0.05). AT 34 degrees C, TP infusion lowered CMRO2 to 2.15 = 0.46 ml 100 g-1 min-1. At 34 degrees C, TP-suppressible and TP-nonsuppressible CMRO2 values were 64 +/- 7% and 36 +/- 8% of total CMRO2, respectively. TP lowered CBF by 50% at both 38 and 34 degrees C. In conclusion, mild hypothermia selectively lowers TP-nonsuppressible CMRO2 associated with the maintenance of viability rather than EEG-associated or TP-suppressible CMRO2.

Source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=8719194&dopt=Abstract barbiturate Butalbital Fioricet





Comparing the bispectral index and suppression ratio with burst suppression of the electroencephalogram during pentobarbital infusions in adult intensive care patients.

Riker RR, Fraser GL, Wilkins ML.

Department of Critical Care, Maine Medical Center, Portland 04102, USA.

OBJECTIVE: The bispectral index (BIS), a processed variable derived from the raw electroencephalogram (EEG) used to guide sedation in the intensive care unit (ICU), has not been tested during barbiturate therapy for elevated intracranial pressure. We determined the BIS and suppression ratio (SR) values during traditional burst monitoring of the raw EEG during pentobarbital infusions. DESIGN: Prospective, observational cohort study. SETTING: A 42-bed multidisciplinary ICU in a tertiary care medical center. PATIENTS: Twelve consecutive patients with elevated intracranial pressure treated with pentobarbital infusions. INTERVENTION: All patients were monitored continuously with the Aspect Medical Systems A-1050 bedside EEG monitor using a bilateral referential montage. Pentobarbital doses were titrated based on the raw EEG to attain a burst-suppression pattern with a goal of 3-5 bursts/minute. Drug dosage, intracranial pressure, cerebral perfusion pressure values, EEG bursts/minute, BIS version 3.2, and SR were recorded daily. MEASUREMENTS AND MAIN RESULTS: The 12 patients were monitored for 62 patient-days. Mean +/- SD age was 32 +/- 15 years, seven (58%) patients were male, mean Acute Physiology and Chronic Heath Evaluation II score was 17.0 +/- 5.0, and hospital mortality was 42%. The mean pentobarbital infusion rate was 124 +/- 49 mg/hour or 2.3 +/- 1.3 mg/kg/hour, and mean pentobarbital serum concentration was 29.7 +/- 13 microg/ml. The mean BIS value was 18 +/- 14, mean SR 56% +/- 36%; BIS correlated well with SR (r=-0.99, p<0.001). For patient-days with a burst-suppression pattern, BIS 3.2 (r=0.90, p<0.001) and SR (r=-0.89, p<0.001) strongly correlated with the number of bursts/minute. The mean BIS value corresponding to 3-5 bursts/minute was 15 (95% confidence interval [CI] 10-20); SR value was 71 (95% CI 61-80). CONCLUSION: The Aspect A-1050 applied to patients and monitored by nurses and physicians works well as a bedside EEG monitor, providing a raw EEG signal to titrate barbiturate therapy. The continuous data trend and real-time digital output for the BIS and SR quantify the degree of EEG suppression well and may prove helpful in facilitating titration of barbiturate infusions.

Source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=14524640&dopt=Abstract barbiturate Butalbital Fioricet





Positive screening tests for barbiturates in urine samples in the York area over a 1-year period.

Holbrook I, Sinclair M, Turley P, Tetlow T.

Department of Chemical Pathology, York District Hospital, UK. Ian.B.Holbrook excha.yhs-tr.northy.nhs.uk

Following the screening of urine samples for a panel of drugs over a period of 1 year, a peak was observed during December 1999 and January 2000 in the numbers of samples testing positive for both morphine and barbiturates. This increase may be due to the adulteration of street heroin with barbiturate during this period.

Source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=11587136&dopt=Abstract barbiturate Butalbital Fioricet