Parenteral routes

The treatment of an autoimmune disease very much depends on the nature of the clinical outcome it causes. Although the formation of autoantibodies causes the inactivation of the gastric intrinsic factor, the subsequent shortage of vitamin B12 can be easily overcome by supplying it via an parenteral route. Lifelong immunosuppression (with all its side effects) thus is inappropriate. When, however, as in sympathetic ophtalmia, after damage of the first eye the second eye is endangered, an even drastic immunosuppression is mandatory. 

The nurse should observe the following points when giving a drug by the parenteral route ... 

More than half of the patients receiving this drug by the parenteral route experience some adverse reaction. Severe and sometimes life-threatening reactions include leukopenia (low white blood cell count), hypoglycemia (low blood sugar), thrombocytopenia (low platelet count), and hypotension (low blood pressure). Moderate or less severe reactions include changes in some laboratory tests, such as the serum creatinine and liver function tests. Other adverse reactions include anxiety, headache, hypotension, chills, nausea, and anorexia Aerosol administration may result in fatigue a metallic taste in the mouth, shortness of breath, and anorexia... 

MANAGING ANXIETY. Fhtients may exhibit varying degrees of anxiety related to tiieir illness and infection and die necessary drug therapy. When these drug are given by die parenteral route, patients may experience anxiety because of the discomfort or pain that accompanies an IM injection or IV administration. The nurse reassures die patient that every effort will be made to reduce pain and discomfort altiiough complete pain relief may not always be possible. 

When administering die antitubercular drug by die parenteral route, die nurse is careful to rotate the injection sites. At die time of each injection, die nurse inspects previous injection sites for signs of swelling, redness, and tenderness. If a localized reaction persists or if die area appears to be infected, it is important to notify die primary health care provider. 

The ongoing assessment involves careful observation of the patient every 2 to 4 hours for adverse drug reactions when the antifungal drug is given by the oral or parenteral route. When these dru are applied topically to the skin, the nurse inspects the area at the time of each application for localized skin reactions. When these dm i are administered vaginally, the nurse questions the patient regarding any discomfort or other sensations... 

Promoting an Optimai Response to Therapy Heparin preparations, unlike warfarin, must be given by the parenteral route, preferably SC or IV The onset of anticoagiilation is almost immediate after a single dose. Maximum effects occur witiiin 10 minutes of administration. Clotting time will return to normal witiiin 4 hours unless subsequent doses are given. 

Iron salts occasionally cause gastrointestinal irritation, nausea, vomiting, constipation, diarrhea, headache, backache, and allergic reactions. The stools usually appear darker (black). Iron dextran is given by the parenteral route Hypersensitivity reactions, including fatal anaphylactic reactions, have been reported with the use of this form of iron. Additional adverse reactions include soreness, inflammation, and sterile abscesses at the intramuscular (IM) injection site Intravenous (IV) administration may result in phlebitis at the injection site When iron is administered via the IM route, a brownish discoloration of tlie skin may occur. Fhtients with rheumatoid arthritis may experience an acute exacerbation of joint pain, and swelling may occur when iron dextran is administered. 

VITAMIN S12. Fhtients with pernicious anemia are treated with vitamin B12 by tiie parenteral route (IM) weekly stabilized. The parenteral route is used because tiie vitamin is ineffective orally due to the absence of tiie intrinsic factor in tiie stomach, which is necessary for utilization of vitamin B12. After stabilization, maintenance (usually monthly) injections are necessary for life... 

Insulin must be administered via the parenteral route, usually the subcutaneous (SC) route Insulin cannot be administered orally because it is a protein and readily destroyed in the gastrointestinal tract. Regular insulin is the only insulin preparation given intravenously (IV). Regular insulin is given 30 to 60 minutes before a meal to achieve optimal results. 

On occasion, a patient may need to self-administer vasopressin by the parenteral route. If so, the nurse instructs the patient or a family member in the preparation and administration of the drug and measurement of the specific gravity of the urine. 

One adverse reaction common to all solutions administered by the parenteral route is fluid overload, that is, the administration of more fluid than the body is able to... 

The chapter covers end points in the same order they appear within the Discussion of Health Effects by Route of Exposure section, by route (inhalation, oral, dermal) and within route by effect. Human data are presented first, then animal data. Both are organized by duration (acute, intermediate, chronic). In vitro data and data from parenteral routes (intramuscular, intravenous, subcutaneous, etc.) are also considered in this chapter. If data are located in the scientific literature, a table of genotoxicity information is included. 

Delivery of peptides and proteins via the gastrointestinal tract has not been successful because of poor penetration through the intestinal epithelium and high levels of proteolytic activity in the gastrointestinal tract. Liposomal encapsulation of proteins and peptides will not improve the efficiency and capacity of this absorption pathway considerably (e.g., Ryman et al., 1982 Machy and Leserman, 1987 Weiner and Chia-Ming Chiang, 1988). These difficulties in delivery via the oral route caused the parenteral route to remain the preferred route for the administration of therapeutic peptides... 

Besides the inhalative use, the development of a drug formulation for A9-THC has to address other bioavailabihty questions. A major problem is the hpophiUcity and poor solubiUty in water, hmiting oral uptake when given orally. Because of this, other parenteral routes of apphcation are imder investigation like puhnonal uptake by vaporization, subUngual or intranasal administration, and apphcation by injection of A9-THC incorporated in hpo-somes. 

Maintaining adequate nutritional status, especially during periods of illness and metabolic stress, is an important part of patient care. Malnutrition in hospitalized patients is associated with significant complications, including increased infection risk, poor wound healing, prolonged hospital stay, and increased mortality, especially in surgical and critically ill patients.1 Specialized nutrition support refers to the administration of nutrients via the oral, enteral, or parenteral route for therapeutic purposes.1 Parenteral nutrition (PN), also... 

Fig. 18 Blood-level curves of identical doses of a drug by parenteral route (I) and by oral route as a solution (II) and as a tablet (III).

Parenteral administration of drugs by intravenous (IV), intramuscular (IM), or subcutaneous (SC) routes is now an established and essential part of medical practice. Advantages for parenterally administered drugs include the following rapid onset, predictable effect, predictable and nearly complete bioavailability, and avoidance of the gastrointestinal (GI) tract and, hence, the problems of variable absorption, drug inactivation, and GI distress. In addition, the parenteral route provides reliable drug administration in very ill or comatose patients. 

In recent years, parenteral dosage forms, especially IV forms, have enjoyed increased use. The reasons for this growth are many and varied, but they can be summed up as (a) new and better parenteral administration techniques, (b) an increasing number of drugs that can be administered only by a parenteral route, (c) the need for simultaneous administration of multiple drugs in hospitalized patients receiving IV therapy, (d) new forms of nutritional therapy, such as intravenous lipids, amino acids, and trace metals, and (e) the extension of parenteral therapy into the home. 

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