International journal of clinical pharmacology, therapy, and toxicology
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Caffeine is ubiquitous in our environment and is the most widely used psychoactive drug in the world. Caffeine works on every system in the body mediated by the central nervous system. Caffeine has the opposite effect of adenosine and is the antagonist at the inhibitory A1-receptor. ⋯ Caffeine is used for the treatment of apnea of prematurity and as an additive in several analgesics and migraine remedies, and as a panacea for hyperkinetic children. Although much work has been done to establish the relationship between caffeine and cancer and mutagenicity, none of these have established a cause-effect relationship. The consumption of caffeine products in moderation appears to be safe at this point.
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Int J Clin Pharmacol Ther Toxicol · Jan 1988
ReviewPropofol, the newest induction agent of anesthesia.
Propofol is a rapidly acting intravenous anesthetic agent which has many advantageous kinetic properties explaining its usefulness by bolus dose for induction of anesthesia or for administration by continuous intravenous infusion. It is rapidly distributed in the body with a half-life of only around 2 min and has an efficient hepatic and extrahepatic clearance (total body clearance may exceed liver blood flow). Premedication has little effect on the already good induction characteristics of propofol. ⋯ Propofol has proved to be a useful induction agent regardless of the age of patients, but in the elderly there appears to exist a marked sensitivity to it. Up to now there is no evidence that propofol in emulsion drug form can produce allergic or anaphylactoid reaction more often than other induction agents in use and no severe hematological nor visceral toxicity have been reported. In the present situation, when althesin is not marketed any more due to a high frequency of anaphylactoid reactions and etomidate will have a limited use in clinical practice because of its blocking effect on adrenocortical function, propofol offers an important alternative anesthetic agent to thiopentone.
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Int J Clin Pharmacol Ther Toxicol · Nov 1985
ReviewCurrent status of labetalol, the first alpha- and beta-blocking agent.
Labetalol is a unique antihypertensive agent which is a competitive peripheral antagonist at both alpha- and beta-adrenoceptor sites. Clinically, it possesses about one fourth of the beta-adrenoceptor blocking activity of propranolol and one half of the alpha-adrenoceptor blocking activity of phentolamine with a beta- to alpha-blocking ratio of approximately 7:1. Nowadays, the clinical profile of labetalol is clearly defined. ⋯ In induced hypotension during anesthesia and surgery no invasive blood pressure measurements are needed. The most frequent adverse effects include fatigue, postural hypotension, headache and gastrointestinal complaints. On the whole, labetalol expands the armamentarium of the practising physician in the treatment of hypertension of different origin.
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Int J Clin Pharmacol Ther Toxicol · Jun 1984
Review Comparative StudyEpidural and intrathecal opiates in obstetrics.
The use of epidural and intrathecal opiates in obstetrics is reviewed. Opiate receptors in the substantia gelatinosa of the spinal cord appear to be the main site of drug action after both epidural and intrathecal modes of drug administration. However, an additional systemic effect for this selective spinal analgesia cannot be excluded, especially after epidural drug administration. ⋯ After intrathecal injection of opiates, there was a strong analgesic action during delivery, but an unacceptable amount of side effects prevents their routine use. In post-cesarean patients, epidurally administered opiates are quite effective analgesics, but they still have one serious unwanted effect: respiratory depression of delayed onset. Thus, in routine obstetric practice, epidural or intrathecal opiates play only a limited role.
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Int J Clin Pharmacol Ther Toxicol · Sep 1983
ReviewPharmacokinetics and the sedative effect of midazolam.
The pharmacokinetics and their relation to the pharmacodynamic properties of midazolam, the first water-soluble benzodiazepine derivative, are reviewed. Pharmacokinetically, midazolam is a unique derivative among the benzodiazepines. After both oral and parenteral routes of administration, it has a fast absorption rate, and differing from older derivatives it is very rapidly excreted with a half-life of only about 2 h. ⋯ Midazolam appears to be a useful short-acting hypnotic having almost no residual effects the following morning. In anesthesiology both oral and parenteral drug forms can be used for premedication. In addition, it is a new alternative for inducing anesthesia when a slow induction time is chosen or its advantageous properties: good cardiovascular stability, transient and mild respiratory depression, low frequency of venous irritation, production of anterograde amnesia, and short duration of action (last-mentioned property in comparison with other benzodiazepines).