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PubMed1988

Adulterants causing false negatives in illicit drug testing.

Illicit-drug users may attempt to falsify results by in vitro adulteration of specimens. We investigated eight additives (NaCl, Visine, handsoap, Drano, bleach, vinegar, golden-seal tea, and lemon juice) claimed by drug users to invalidate enzyme immunoassay (EIA) drug assays. We also analyzed adulterated urine specimens to determine if they could be identified, adding adulterants at several concentrations to 222 EIA-positive specimens confirmed by gas chromatography and mass spectrometry (GC/MS) to contain illicit drugs. To identify adulterated urines, we monitored pH, relative density, and urine color and turbidity at adulterant concentrations that falsified EIA results. Specimens contaminated with NaCl had relative densities greater than 1.035. Liquid Drano, bleach, and vinegar shifted urine pH outside the physiological range. Golden-seal tea caused a dark appearance, and specimens containing liquid soap were unusually cloudy. Lemon juice had no effect on the assays. Visine was the only adulterant not detected. The adulterants interfered somewhat differently with each of the drug assays. EIA assays for illicit drugs can be invalidated by specimen adulteration producing false-negative results. Therefore, if urine drug testing is to be conducted, pH, relative density, and appearance should be assessed and suspect specimens should be rejected. Not all adulterants can be detected, so observed collection is strongly recommended.

Acetates↗
PubMed1985

Metabolic mechanisms of drug-nutrient interactions.

Metabolic mechanisms of nutrition and drug interactions include 1) the effects of diet on drug metabolism and action and 2) the effects of drugs on nutritional processes. The type, amount, and timing of foods consumed influence drug dissolution, absorption, distribution, metabolism, and excretion. High-fat meals enhance the absorption of griseofulvin and some other drugs. Milk and other sources of calcium inhibit absorption of tetracycline. High-fat meals increase plasma concentrations of free fatty acids and thereby displace many drugs from binding sites on plasma albumin. High-protein diets increase the activity of the mixed-function oxidase system and enhance the metabolism of numerous drugs. High-electrolyte intakes increase excretion of lithium and also diminish the action of diuretic agents. Bile acid sequestrants and some laxatives decrease lipid digestion and absorption, as well as absorption of the fat-soluble vitamins. Numerous drugs, including tetracycline and cholestyramine, bind iron and decrease its absorption. Coumarins inhibit the function of vitamin K. Phenobarbital and other anticonvulsants are inducers of cytochrome P-450 and the mixed-function oxidase system. Long-term treatment with these inducers can cause excessive metabolism and deficiency of vitamin D. Prooxidant drugs such as chloroquine, drugs detoxified by conjugation with glutathione, and alcohol can deplete reduced glutathione with consequent effects on amino acid transport and the redox status of cells. Acid-forming foods acidify the urine and increase the loss of alkaline drugs such as the amphetamines. Base-forming drugs increase the loss of acidic drugs such as barbiturates. The range of metabolic interactions of drugs and nutrients includes the full scope of physiological processes to which drugs and nutrients are subject.

Absorption↗
PubMed1981

Kinetics of drug decomposition. Part 69: Effect of excipients on the thermal decomposition of the mixture of aminophenazone allobarbital and adiphenine hydrochloride in the solid.

By the method of accelerated testing at elevated temperature, the thermal decomposition rate of the mixture of aminophenazone (AP), allobarbital (AB) and adiphenine hydrochloride (AD) and its individual components in the presence of the excipients starch (potato), agar, talcum, kaolin and magnesium stearate is studied. The individual and joint effect of the excipients on the components of the mixture AP + AB + AD as well as on the mixture as a whole is determined and compared. The theoretically predicted stability of the components is discussed and compared with the results of "self-life" tests in the presence and absence of the excipients.

Aminopyrine↗
PubMedDate not supplied

Kinetics of drug decomposition. Part 60. Thermal decomposition of the mixture of aminophenazone, allobarbital and adiphenine hydrochloride in the solid state.

Kinetics of decomposition of a mixture of aminophenazone, allobarbital and adiphenine hydrochloride has been examined using accelerated testing at elevated temperatures (333-353 K). The reaction order, rate constants and activation parameters (Q10 degrees, EA, delta H#, delta S#, delta G) have been determined and compared for each component, in the presence of each component of the mixture and in the presence of two components of the mixture. The effect of individual components of the mixture on the rate of decomposition of the other components has been observed, the value of this effect has been determined using the rate constants obtained. The rate constants and times t10% for room temperature were calculated. The "shelf-life time" (t10%) was calculated from accelerated testing data at elevated temperature and compared with that obtained for Vegantalgin ragées in the mixture studied at 293 K.

Aminopyrine↗
PubMed1981

Methotrexate for psoriasis: 1981.

Although not stated in body of this article, it is best to start treatment with a very small test dose. Furthermore, one should use methotrexate only when other methods fail or are impractical. In general, the criterion of life-ruining disease should be considered the primary indication. Drugs interactions should be avoided. Probenecid, phenylbutazone, and colchicine are contraindicated. Increased toxicity may occur with concomitant use of salicylates, sulfonamides, barbiturates, para-aminobenzoic acid, diphenylhydantoin, oral contraceptives, and weak organic acids. It would appear at this time that any dose being administered more often than once weekly is too toxic for the liver. Perhaps the intramuscular route is safest. Finally, the official guidelines should be followed as closely as possible, even possibly including liver biopsies. It should be recognized that liver biopsy is not without hazard, as deaths have been reported from simple needle liver biopsies.

Drug Administration Schedule↗