Dose, single

Tetrahydronaphthalene is not a highly toxic compound. A threshold limit value of 25 ppm or 135 mg/m has been suggested for Tetralin. Tetralin vapor is an irritant to the eyes, nose, and throat, and dermatitis has been reported in painters working with it (28). The single-dose oral toxicity LD q for rats is 2.9 g/kg (29). 

Commercially available containers for use with parenteral products include single-dose ampuls that are heat sealed and opened by snapping at the point of least diameter, vials for multidose use, and botdes and pHable bags that are used for large volumes such as needed in intravenous infusions. Container size can vary from 1 mL to 1 L. Generally volumes up to 100 mL are available as ampuls or vials. 

Single-dose preparations intended for use in eye surgery do not contain excipient ingredients, in order to avoid tissue irritation. However, multiple-dose containers may require antioxidants (qv), antimicrobial preservatives, or buffers to maintain stabiHty and stefiHty. Such solutions are packaged in polyethylene flexible dropper units called droptainers or in glass dropper botdes. 

The acute toxicity of MSG is low (31) the oral LD q for humans, calculated on the basis of doses a dministered in different ways to various animals, would represent a single dose greater than 1 kg for a person weighing 70 kg. In contrast, the oral LD q for sodium chloride in rats is 3.75 g/kg body weight (32). 

Single dose or short-term treatment with aerosolized steroids inhibits both the late asthmatic response and allergen-induced bronchial hyperresponsiveness (45,92). However it does not affect the early asthmatic response nor does it induce bronchodilation (45,92). Long-term treatment with steroids protects against both the early and late asthmatic responses and also reduces bronchial hyperresponsiveness (44,71,86,93). Over time, the airways relax (dilate) and measures of airway function, such as forced expiratory volume in one second (FEV ), gradually return to almost normal levels. 

Fig. 4. Semm levels in mice of chloramphenicol (1, R = NO2) thiamphenicol (1, R = CH2SO2) O, and florfenicol (2) I, following a single dose of 200...

Technetium-99m exametazime [(RR,3 3)-4,8-diaza-3,6,6,9-tetramethylundecane-2,10-dionebisoxime] is used as an adjunct in the detection of altered regional cerebral perfusion in stroke. The kit for the preparation of the radiopharmaceutical is suppHed as a single dose vial. 

The potential for normal brain tissue injury is one of the limiting factors in the use of XRT for brain tumors. Pentobarbital is a cerebral radioprotectant in rodent and primate models after single doses, but is associated with significant risks. Of alternative barbiturates, thiopental given to tats receiving 70-Gy (7000-rad) whole-brain irradiation in a single fraction enhances the 30-day survival similarly to pentobarbital, whereas ethohexital and phenobarbital show no radioprotective activity (250). 

Varicella. The varicella (chicken pox) vacciae was approved ia April 1995 for immunisation of children. A single dose at one year of age is recommended. In the future it may be combiaed with measles, mumps, and mbeUa. 

The dmg is readily absorbed from the gastrointestinal tract and may persist in human tissues for two months after adrninistration. Quinacrine is given as a single dose for the treatment of tapeworms it is manufactured by Winthrop-Breon of New York, New York. 

Pyrantel Pamoate. This dmg (10), C24H2qN20 S, cures pinworm infections and is close to 100% effective against A.scaris when given in a single dose (28,29). Pyrantel pamoate is also a principal dmg for the treatment of hookworm infections thus it is useful in patients with mixed worm infections. 

Dichloroethane is one of the more toxic chlorinated solvents by inhalation (49). The highest nontoxic vapor concentrations in chronic exposure studies with various animals range from 100 to 200 ppm (50,51). 1,2-Dichloroethane exhibits a low single-dose oral toxicity in rats LD q is 680 mg/kg (49). Repeated skin contact should be avoided since the solvent can cause defatting of the skin, severe irritation, and moderate edema. Eye contact may have slight to severe effects. 

Contact or ingestion of cyanamide must be avoided, and precautions taken to prevent inhalation of dust or spray mist. In rat studies cyanamide-100 toxicity ranges from a single oral dose LD q of 280 mg/kg to a single dermal dose LD q of 590 (420—820) mg/kg. The compound is, therefore, considered to be moderately toxic both by ingestion in single doses and by single-skin appHcations. An aqueous paste of the product is corrosive to rabbit skin. Small quantities of the dry product produced severe irritation when introduced into the conjunctival sac of the rabbit eye. 

Cyanamide-50 is considered to be slightly toxic by ingestion in single dose and moderately toxic by single-skin appHcations. The degree of irritation to rabbit skin and eye produced by this product is only slightly less than that observed with Cyanamide-100. 

Diglycidyl Ether of Bisphenol A. The Hquid DGEBPA-based resins exhibit low acute toxicity with a single-dose oral LD q value in rats of >2000 mg/kg (40). The potential for absorption of DGEBPA through the skin in acutely toxic amounts is low. LD q values of >800 mg/kg for acute dermal toxicity have been obtained from studies using both the pure and commercial DGEBPA (41,42). 

The single dose of a drug is mo.stly derived from experience it is only possible in a very few cases to calculate it from the activity of the constituents. However, as many herbal drugs arc only weakly active and contain non-toxic substances, i.e, the therapeutic index is large, exceeding the dose is usually only of minor significance nevertheless, the pharmacist must know what the exceptions are in this book, the sections on Side effects and Making the tea draw particular attention to such cases, c.g. arnica flowers, liquorice root, etc. 

Amount of drug (a single dose) and Degree of comminution of the drug amount of liquid... 

ACUTE TOXICITY Advcfse health effects occumng within a short time period of exposure to a single dose of a chemical or as a result of multiple exposures over a short time period, e.g. 24 hours. 

Generally a serious exposure refers to a large, single dose received over a short period of time and an immediate response occurs, (acute)... 

A serious exposure may also result from a small, single dose over a short period of time and there is no immediate effect. This small dose may exceed t e threshold sensitivity of the individual causing a serious delayed effect. The classic exeimple of this is cancer. 

Acute Toxicity The adverse effect occurring within a short time of (oral) administration of a single dose of a substance or multiple doses given within 24 hours. 

Median Effective Dose (ED) The statistically derived single dose of a substance that can be expected to cause a defined nonlethal effect in 50% of a given population of organisms under a defined set of e.xperimental conditions. 

Table A lists some of the effects to be expected when a person is exposed to a single dose of radiation at various levels.

FIGURE 11.4 Two-way analysis of variance. Arrangement of data in rows and columns such that each row of the cell culture plate (shown at the top of the figure) defines a single dose-response curve to the agonist. Also, data is arranged by plate in that each plate defines eight dose-response curves and the total data set is comprised of 32 dose-response curves. The possible effect of location with respect to row on the plate and/or which plate (order of plate analysis) can be tested with the two-way analysis of variance. 

FIGURE 11.16 Control dose-response curve and curve obtained in the presence of a low concentration of antagonist. Panel a data points. Panel b data fit to a single dose-response curve. SSqs = 0.0377. Panel c data fit to two parallel dose-response curves of common maximum. SSqc = 0.0172. Calculation of F indicates that a statistically significant improvement in the fit was obtained by using the complex model (two curves F = 4.17, df=7, 9). Therefore, the data indicate that the antagonist had an effect at this concentration. 

---