Decrease of Body Temperature

Opioids can have profound effects on body temperature however, depending on the particular conditions under which the compound is evaluated either increases or decreases in body temperature can be observed. Route of administration, dose, age of the 

Geller EB, Adler MW (1990) Drugs of abuse and body temperature. In Modem Methods in Pharmacology, Vol 6, Testing and Evaluation of Drags of Abuse, Wiley-Liss, Inc., pp 101-109 

Holtzman SB, Villarreal JE (1969) Morphine dependence and body temperature in rhesus monkeys. J Pharmacol Exp Ther 166 124-133 

McDougal JN, Marques PR, Burks TF (1983) Restraint alters the thermic response to morphine by postural interference. Pharmacol Biochem Behav 18 495-499 

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In studies conducted in the 1960s in a model of complete brain ischemia in rabbits, it was shown that the duration of tolerable ischemia compatible with complete functional and histological recovery increased continuously with declining temperature, and could be extended fivefold by reducing temperature from 37°C to 25°C (18). Other workers showed that a decrease of body temperature of only 1-3°C reduced the degree of brain energy metabolite depletion and acidosis in a model of carotid ligation and hypoxia (19). 

Cold-blooded animals decrease their body temperature in cold weather to match that of their environment. The activation energy of a certain reaction in a cold-blooded animal is 65 kj/mol. By what percentage is the rate of the reaction decreased if the body temperature of the animal drops from 35°C to 22°C ... 

Evaluating and recording die patient s response to the drug (when applicable). Evaluation may include such facts as relief of pain, decrease in body temperature, relief of itching, and decrease in the number of stools passed. 

Methods of detection, metabolism, and pathophysiology of the brevetoxins, PbTx-2 and PbTx-3, are summarized. Infrared spectroscopy and innovative chromatographic techniques were examined as methods for detection and structural analysis. Toxicokinetic and metabolic studies for in vivo and in vitro systems demonstrated hepatic metabolism and biliary excretion. An in vivo model of brevetoxin intoxication was developed in conscious tethered rats. Intravenous administration of toxin resulted in a precipitous decrease in body temperature and respiratory rate, as well as signs suggesting central nervous system involvement. A polyclonal antiserum against the brevetoxin polyether backbone was prepared a radioimmunoassay was developed with a sub-nanogram detection limit. This antiserum, when administered prophylactically, protected rats against the toxic effects of brevetoxin. 

In gas-uptake experiments, Gearhart et al. (1993) demonstrated a dose-dependent decrease in core body temperature with increased inhaled concentrations of chloroform. The decrease in body temperature could account for decreased in vivo chloroform metabolism, partition coefficients, pulmonary ventilation, and cardiac output rates in mice. 

The salicylates are also potent antipyretic agents, with the exception of diflunisal, which is only weakly active. Aspirin acts at two distinct but related sites. It decreases prostaglandin-induced fever in response to pyrogens and induces a decrease in interleukin-1 modulation of the hypothalamic control of body temperature. Thus, the hypothalamic control of body temperature returns, vasodilation occurs, heat dissipates, and fever decreases. Other uses of aspirin include inhibition of platelet aggregation via inhibition of thromboxanes, which has been shown to decrease the incidence of blood clots, myocardial infarction, and transient ischemic attacks. 

Brun et al. (216) evaluated the mental performance, hormone levels, and temperatures of eight sleep-deprived volunteers given 300-mg of modafinil at 22 00 and 08 00. Modafinil did not affect melatonin, cortisol, or growth hormone levels, but it did attenuate performance decrements, attenuate the nocturnal decrease in body temperature, and increase daytime body temperature. These temperature effects are different from what has been observed in non-sleep-deprived subjects. Bourdon et al. (217) found no effects of 200 mg of modafinil on thermal balance in neutral conditions and no effect on thermoregulation in cold conditions (despite a tendency toward greater reductions in core temperature when modafinil was applied in a cold environment). However, these authors did not examine temperature effects beyond 3 hr in the morning. The differences with... 

Aspirin and other salicylates are used in the treatment of mild to moderate pain. Aspirin is commonly used to treat headache (including migraine and tension type) and to decrease elevated body temperature. Salicylic acid, as a 10% to 20% solution in alcohol or propylene glycol, is used for the treatment of corns. 

Continuous hemodynamic monitoring is essential during all phases of hypothermia. Cardiac monitoring is necessary because of the increased risk of arrhythmias. Cardiac output is decreased 5% for every 1°C of body temperature reduction. This is thought to be secondary to bradycardia, which has been shown to occur with hypothermia (3). A pulmonary artery catheter may be placed if there is any question of hemodynamic instability. Arterial catheters are used for continuous blood pressure measurement, as well as for access to arterial blood for blood gas and electrolyte analysis. 

The mean time to death (LTso) values were prolonged in mice that were pretreated with vitamin E, Vitamin A, and/or glucose 30 minutes before dosing with DNOC (Tesic et al. 1972). In addition, thiamazole increased the LTso value by a factor of 2.72, while chlorpromazine had a greater influence on LTso values and was more protective than thiamazole in DNOC treated mice. Doses of 8 and 12 mg/kg chlorpromazine were more protective than doses <6 mg/kg, which had no protective effect. The authors proposed that larger doses of chlorpromazine may cause a significant reduction in oxidative processes and decrease in body temperature, while the protective effect of thiamazole may be associated with its ability to decrease basal metabolic rate. 

Dog 3 Whole body 180-200 30 min Ginical signs included lacrimation, salvation, retching, vomiting, reduction in muscle activity, dyspnea. Slight decrease in body temperature. No evidence of bronchitis or pulmonary edema. LOAEL 180 Barbour 1919 (ss cited in NIOSH1976)... 

Antimuscarinic syndromes consist of tachycardia, dilated pupils, dry, flushed skin, urinary retention, decreased bowel sounds, mild elevation of body temperature, confusion, cardiac arrhythmias and seizures. They are commonly caused by antipsych-otics, tricyclic antidepressants, antihistamines, anti-spasmodics and many plants (see p. 160). 

These data are relevant clinically because of possible wide variation of body temperature in the surgical patient. Body temperature may be lowered as a result of preoperative sedation, by cutaneous vasodilation, by the infusion of cold fluids and by reduced metabolism under operating conditions. The increase in oil/gas partition coefficient with decreasing temperature means that the effective concentration at the hydrophobic site of action is increasing and hence the apparent potency of the anaesthetic increases. 

Cardiotoxicity of isoproterenol (IPR) Male Sprague-Dawley rats Decreased core body temperature of DR rats after IPR treatment... 

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