Oral route effective

Reproductive toxicity to 2,3,7,8-TCDD has been demonstrated in animals. "" The effects include pre- and postimplantation losses in females, morphologic and functional changes in male and female reproductive organs, and hormonal imbalance in both sexes. A number of developmental effects have been observed in animals acutely exposed to 2,3,7,8-TCDD by the oral route. Effects observed in offspring of animals include cleft palate, kidney anomalies, immune system damage (thymic atrophy and immunosuppression), impaired development of the reproductive system, decreased growth, and fetal/newborn mortality. 

One of the most toxic organophosphorus insecticides highly toxic by oral route effects are cumulative toxic symptoms are similar to those of other cholinesterase inhibitors and include nausea, vomiting, diarrhea, excessive salivation, blurred vision and pain in eye muscle, convulsion, coma, and respiratory failure probable lethal dose is estimated to be 5-10 g for adult humans. 

Several mucolytics reduce the viscosity of mucus by cleaving the disulfide bonds that maintain the gel stmcture. AJ-Acet l-L-cysteine [616-91 -1] (19), introduced in 1963, and mesna [19677-45-5] (20), developed in Europe in the early 1970s (20,21), are effective compounds in this class. Whereas most mucolytics must be adrninistered by aerosol, carbocysteine [638-23-6] (21), which contains a derivatized sulfhydryl group, has shown activity by the oral route (22,23). However, carbocysteine does not reduce mucus viscosity, as does acetylcysteine, but appears to have a direct action on mucus glycoprotein production (24). 

FIGURE 8.23 Kinetic profiles of the plasma concentrations of three different drags taken by the oral route. If absorption is rapid, toxic effects may ensue (red line). If too slow, a therapeutically effective level may not be attained (blue line). 

Decongestants are used to treat the congestion associated with rhinitis, hay fever, allergic rhinitis, sinusitis, and the common cold. In addition, they are used in adjunctive therapy of middle ear infections to decrease congestion around the eustachian tube Nasal inhalers may relieve ear block and pressure pain during air travel. Many can be administered orally as well as topically, but topical application is more effective than the oral route. 

The pretreatment of MH-susceptible patients with oral or intravenous dantrolene prior to surgery in order to avoid a crisis is controversial. Most physicians do not recommend prophylactic pretreatment except in patients who have had a previously documented episode. However, if pretreatment is desired, it is recommended that therapy be begun with intravenous dantrolene in a dose of 2 mg/Kg just prior to induction of anesthesia. This prevents the uncertainty of predictive blood values associated with the use of the oral route. The adverse effects of intravenous dantrolene prophylaxis include phlebitis and tissue necrosis. Patients who receive prophylactic treatment with oral dantrolene often complain of incapacitation, gastrointestinal irritation, prolonged drowsiness, and clinically significant respiratory muscle weakness. 

Estimates of exposure levels posing minimal risk to humans (Minimal Risk Levels or MRLs) have been made for methyl parathion. An MRL is defined as an estimate of daily human exposure to a substance that is likely to be without an appreciable risk of adverse effects (noncarcinogenic) over a specified duration of exposure. MRLs are derived when reliable and sufficient data exist to identify the target organ(s) of effect or the most sensitive health effect(s) for a specific duration within a given route of exposure. MRLs are based on noncancerous health effects only and do not consider carcinogenic effects. MRLs can be derived for acute, intermediate, and chronic duration exposures for inhalation and oral routes. Appropriate methodology does not exist to develop MRLs for dermal exposure. 

Immunotoxicity. Only a single case report of skin allergy to methyl parathion has been reported in humans (Lisi et al. 1987). No studies are available in humans exposed to methyl parathion via the inhalation or oral route. Based on limited animal studies, immunotoxicity may be a sensitive end point of methyl parathion-induced toxicity (Shtenberg and Dzhunusova 1968 Street and Sharma 1975). Thus, humans may be at risk for adverse immunological effects following exposure to methyl parathion. The limited information available on the effects of combined exposure to methyl parathion suggest the its toxicity is not route-dependent. Therefore, there is no reason to suspect that the immunotoxic effects observed following oral exposure of animals are route-specific. 

Where sufficient toxicologic information is available, we have derived minimal risk levels (MRLs) for inhalation and oral routes of entry at each duration of exposure (acute, intermediate, and chronic). These MRLs are not meant to support regulatory action but to acquaint health professionals with exposure levels at which adverse health effects are not expected to occur in humans. They should help physicians and public health officials determine the safety of a community living near a chemical emission, given the concentration of a contaminant in air or the estimated daily dose in water. MRLs are based largely on toxicological studies in animals and on reports of human occupational exposure. 

There is no evidence that intravenous corticosteroid administration is more effective than oral administration, and the oral route is preferred in acute severe asthma.3 There are also few data to guide selection of initial corticosteroid doses. Recommended doses for acute severe asthma are shown in Table 11-5, page 227 however, recent data indicate that... 

Antiemetics can be administered either intravenously or orally in this situation, depending on patient characteristics such as ability to take oral medications, dosage form availability, and cost considerations.5,10 The intravenous and oral routes are equally effective. When used at equipotent doses, the 5-HT3 antagonists have similar efficacy in preventing acute CINV, despite pharmacokinetic and receptor binding affinity differences.5,10,36... 

Hepatitis E is similar to hepatitis A in that the mode of transmission is via the fecal-oral route. Therefore, the most effective ways to prevent acquiring the virus are good personal hygiene and proper disposal of sanitary waste. Frequent handwashing and avoiding contaminated foods and vegetables decrease the risk of infection. 

An alternative to the oral route is the buccal mucoadhesive system. The Striant buccal system adheres to the inside of the mouth and the testosterone is absorbed through the oral mucosa and delivered to the systemic circulation. There is no first-pass effect, as the liver is bypassed by this route of administration. Patients apply a 30-mg tablet to the upper gum twice daily. The cost is similar to that of the patch or gel. Side effects unique to this dosage form include oral irritation, bitter taste, and gum edema. 

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