Clinical use of appetite suppressants

General anesthesia and chronic amphetamine use: should the drug be stopped preoperatively?

Prescription amphetamines are being used more often for several medical conditions. Anesthesia concerns focus on the cardiovascular stability of patients who may be catecholamine-depleted and thus have a blunted response to intraoperative hypotension. Previously we reported one case of a patient receiving chronic amphetamine therapy who had a stable intraoperative course. We now report eight additional patients taking chronic prescription amphetamines who underwent a safe general anesthesia and outcome. Predominantly prescribed for narcolepsy and attention deficit hyperactivity disorder, amphetamine drugs had been given to these 8 patients for 2 to 10 yr. Ages ranged from 22 to 77 yr and genders were equally divided. All required general anesthesia for their surgical procedures and 6 of the 8 patients were tracheally intubated. Anesthesia operating room times ranged from 30 min to 4.25 h. The authors conclude that amphetamine use need not be stopped before surgery and anesthesia.

Precursor medications as a source of methamphetamine and/or amphetamine positive drug testing results

Medical Review Officer interpretation of laboratory results is an important component of drug testing programs. The clinical evaluation of laboratory results to assess the possibility of appropriate medical use of a drug is a task with many different facets, depending on the drug class considered. This intercession prevents the reporting of positive results unless it is apparent that drugs were used illicitly. In addition to the commonly encountered prescribed drugs that yield positive drug testing results, other sources of positive results must be considered. This review describes a series of compounds referred to as "precursor" drugs that are metabolized by the body to amphetamine and/or methamphetamine. These compounds lead to positive results for amphetamines even though neither amphetamine nor methamphetamine were used, a possibility that must be considered in the review of laboratory results. Description of the drugs, their clinical indications, and results seen following administration are provided. This information allows for the informed evaluation of results with regard to the potential involvement of these drugs.

General anesthesia in a patient on long-term amphetamine therapy: is there cause for concern?

IMPLICATIONS

Amphetamines are powerful, sympathomimetic amines that, when used chronically, can profoundly effect a patient's cardiovascular stability during anesthesia and surgery. Amphetamines are the third most widely abused class of drugs in the United States. They also have legitimate medical use for attention deficit disorder with hyperactivity, exogenous obesity, and narcolepsy. We report a case of a patient with a 40-yr history of chronic amphetamine use having undergone two general anesthesias without complication.

Illegal or legitimate use? Precursor compounds to amphetamine and methamphetamine

The interpretation of methamphetamine and amphetamine positive test results in biological samples is a challenge to clinical and forensic toxicology for several reasons. The effects of pH and dilution of urine samples and the knowledge about legitimate and illicit sources have to be taken into account. Besides a potentially legal prescription of amphetamines, many substances metabolize to methamphetamine or amphetamine in the body: amphetaminil, benzphetamine, clobenzorex, deprenyl, dimethylamphetamine, ethylamphetamine, famprofazone, fencamine, fenethylline, fenproporex, furfenorex, mefenorex, mesocarb, and prenylamine. Especially the knowledge of potential origins of methamphetamine and amphetamine turns out to be very important to prevent a misinterpretation of the surrounding circumstances and to prove illegal drug abuse. In this review, potential precursor compounds are described, including their medical use and major clinical effects and their metabolic profiles, as well as some clues which help to identify the sources.

Combined effects of diethylpropion and alcohol on locomotor activity of mice: participation of the dopaminergic and opioid systems

The widespread consumption of anorectics and combined anorectic + alcohol misuse are problems in Brazil. In order to better understand the interactive effects of ethanol (EtOH) and diethylpropion (DEP) we examined the locomotion-activating effects of these drugs given alone or in combination in mice. We also determined whether this response was affected by dopamine (DA) or opioid receptor antagonists. A total of 160 male Swiss mice weighing approximately 30 g were divided into groups of 8 animals per group. The animals were treated daily for 7 consecutive days with combined EtOH + DEP (1.2 g/kg and 5.0 mg/kg, ip), EtOH (1.2 g/kg, ip), DEP (5.0 mg/kg, ip) or the control solution coadministered with the DA antagonist haloperidol (HAL, 0.075 mg/kg, ip), the opioid antagonist naloxone (NAL, 1.0 mg/kg, ip), or vehicle. On days 1, 7 and 10 after the injections, mice were assessed in activity cages at different times (15, 30, 45 and 60 min) for 5 min. The acute combination of EtOH plus DEP induced a significantly higher increase in locomotor activity (day 1: 369.5 +/- 34.41) when compared to either drug alone (day 1: EtOH = 232.5 +/- 23.79 and DEP = 276.0 +/- 12.85) and to control solution (day 1: 153.12 +/- 7.64). However, the repeated administration of EtOH (day 7: 314.63 +/- 26.79 and day 10: 257.62 +/- 29.91) or DEP (day 7: 309.5 +/- 31.65 and day 10: 321.12 +/- 39. 24) alone or in combination (day 7: 459.75 +/- 41.28 and day 10: 427. 87 +/- 33.0) failed to induce a progressive increase in the locomotor response. These data demonstrate greater locomotion-activating effects of the EtOH + DEP combination, probably involving DA and/or opioid receptor stimulation, since the daily pretreatment with HAL (day 1: EtOH + DEP = 395.62 +/- 11.92 and EtOH + DEP + HAL = 371.5 +/- 6.76; day 7: EtOH + DEP = 502.5 +/- 42.27 and EtOH + DEP + HAL = 281.12 +/- 16.08; day 10: EtOH + DEP = 445.75 +/- 16.64 and EtOH + DEP + HAL = 376.75 +/- 16.4) and NAL (day 1: EtOH + DEP = 553.62 +/- 38.15 and EtOH + DEP + NAL = 445.12 +/- 55.67; day 7: EtOH + DEP = 617.5 +/- 38.89 and EtOH + DEP + NAL = 418.25 +/- 61.18; day 10: EtOH + DEP = 541.37 +/- 32.86 and EtOH + DEP + NAL = 427.12 +/- 51.6) reduced the locomotor response induced by combined administration of EtOH + DEP. These findings also suggest that a major determinant of combined anorectic-alcohol misuse may be the increased stimulating effects produced by the combination.

Serotonergic modulation of ingestive behavior in pigeons

The effects of peripheral administration of the serotonin agonist zimeldine and the serotonin antagonist cyproheptadine on food and water consumption were evaluated in domestic pigeons. Injections of zimeldine reduced the amount of feeding and drinking dose-dependently in 24-hr fasted animals. Administration of cyproheptadine enhanced food and water consumption dose-dependently up to a dose of 160 micrograms per 100 g body weight in nondeprived pigeons. Higher doses reduced ingestion probably due to a general behavioral depression. The effect of zimeldine was antagonized by cyproheptadine. It is concluded that, as in mammals, serotonin participates as an inhibitor in the regulation of feeding in birds. Contrary to the situation in mammals it has no activating effect on drinking but leads to a reduction of water consumption in pigeons.