Phencyclidine (PCP) is a popular illicit drug often misrepresented as some other hallucinogenic substance and distributed in widely varying dosage forms and strengths. Users of hallucinogenic drugs may present with unintentional PCP overdoses. Toxicological laboratory analyses are essential to establish the diagnosis. In nine admitted overdose patients, the consciousness level ranged from alert to comatose on presentation, and all showed a prolonged recovery phase with agitation and toxic psychosis. Severe behavior disorder, paranoid ideation, and amnesia for the entire period of in-hospital stay are characteristic. In very high dose patients, shallow respiratory excursions and periods of apnoea and cyanosis coincided with generalized extensor spasm and spasm of neck muscles. Excessive bronchial secretions, gross ataxia, opisthotonic posturing, and grimacing occur. PCP toxic psychosis should be considered in drug-abusing patients presenting with schizophrenic-like symptoms, psychosis, or other bizarre behavior, whether or not they admit to taking PCP.

From 3,548 drug overdose or abuse cases presenting at 21 Metropolitan Toronto hospitals' Emergency departments, data concerning demographic and medical characteristics, investigative and management procedures, drug analysis services, and disposition of patients were collected. Of the 3,548 cases, 2,723 (77%) were acute overdose and 816 (23%) were drug abuse. Drug overdose was more common than drug abuse for both sexes, but was more characteristic of females. The drugs most frequently alleged ingested were benzodiazepines (34%), ethanol (32%), salicylates (16%), and barbiturates (14%). The frequency with which particular classes of drugs are alleged in overdose corresponds closely to the frequency of prescribing these drugs in Ontario.

Persons admitted to hospital emergency rooms for treatment of drug misuse with concomitant alcohol use were generally found to be heavy drinkers.

The disposition of chlordiazepoxide (50 mg, intravenously), diazepam (0.143 mg/kg, orally), and oxazepam (0.429 mg/kg, orally) were studied in normal and alcoholic men before and after chronic disulfiram administration. Decreases in the plasma clearance of chlordiazepoxide (54%, p < 0.05), diazepam (41%, p < 0.05), and their active N‐desmethyl metabolites were observed. Oxazepam has no important active metabolites and its net disposition is minimally altered by disulfiram. Oxazepam disposition is unaffected by age and liver disease. These considerations together with that of the short half‐life of oxazepam (median, 6.1 hr) suggest that oxazepam may be the drug of choice if benzodiazepine therapy is used for patients taking disulfiram.

Specific deuterium labeling of methadone and use of gas chromatography-mass spectroscopy technique permits rapid and quanitative determination of the ratio of the labeled to unlabeled drug in body fluids. A trideuertiomethadone (methadone-d3) was shown to have exactly the same analgesic activity and toxicity in mice as methadone. The rates of absorption, distribution, and excretion of methadone-d3 and methadone were identical in rats. These observations suggest that methadone-d3 may be used as an in vivo marker for monitoring methadone intake of patients, and thus may improve the effectiveness of methadone treatment programs.

A recent marked increase in “street-drug” phencyclidine use and the subsequently associated overdoses has made development of an assay for the drug in biological fluids important. Phencyclidine in biologic samples was extracted into petroleum ether which was dried, and the residue obtained on drying was redissolved in chloroform for gas chromatographic analysis with a flame ionization detector. Ketamine was used as an internal standard. The method was used to determine the diagnosis of phencyclidine overdose in nine patients and to follow the gradual improvement in clinical course. The plasma half-life of phencyclidine is approximately 11 hr.

(1975). Impurities in Street Phencyclidine. Journal of Psychedelic Drugs: Vol. 7, No. 4, pp. 397-397.

The considerations necessary to describe the effects of combinations of drugs in a biological system are reviewed. The terms which express these effects-additive, potentiative, antagonistic, synergistic-have not had specific operations applied to them and mathematical models have been sought to define these operations. The models should (1) describe the nature of the action of single drugs, (2) classify the results of drug combinations, (3) provide a set of operations for deciding the outcome of combinations, and (4) predict all possible results of a combination from a knowledge of each drug acting alone. Research on the effects of alcohol and meprobamate and their interactions is reviewed, including behavioral and pharmacological studies and also some studies of the interaction of alcohol with other drugs. The task of characterizing the relation between the drug and response is formidable because complex physiological and biochemical processes determine the relationship between administered and effective dose and are further complicated by route of drug administration and various time relations. The descriptions of biochemical and physiological events seem well advanced; those of behavior are not. Much of the behavioral research assumes that a single dose is representative of all doses of the drug, and that combinations of the drugs and additivity of effects can be determined without a rigorous definition or means of application. [Bibliography of 249 items.]