Anaphylactic systemic hypotension

Dopamine exhibits its primary action of the cardiovascular system, kidneys, and mesentery. It is used as a temporary agent for treating hypotension and circulatory shock caused by myocardial stroke, trauma, kidney rejection, and endogenous septicemia. The main indication for use of this drag is shock of various origins (cardiogenic, postoperational, infectious-toxic, anaphylactic), severe hypotension, and imminent renal insufficiency. Synonyms of dopamine are dopamin and inotropin. 

Anaphylactic reactions occur in 1% of patients with diabetes mellitus who have received protamine-containing insulin NPFl insulin or protamine zinc insulin) but are not limited to this group. A less common reaction consisting of pulmonary vasoconstriction, right ventricular dysfunction, systemic hypotension, and transient neutropenia also may occur after protamine administration. 

All of the foregoing cardiovascular and ventilatory and respiratoiy responses—namely, apnea followed by tachypnea, bradycardia, and increased bronchial blood flow, as well as systemic hypotension—observed in the pulmonary chemoreflex are characteristic of an anaphylactic reaction (31). An example of the cardiopulmonary responses to an inhaled allergen in a spontaneously breathing dog is shown in Figure 5. There is an increase in transpulmonary pressure indicative of an increase in airways resistance and a decrease in dynamic compliance. There is a marked apnea followed by tachypnea, a marked bradycardia and hypotension. Albeit, there may be some compensatory increase in heart rate, the induced hypotension persists. This hypotension is probably, partly, mediated by the induction of nitric oxide (NO) through the parasympathetically induced activation of nitric oxide synthase (32,33). 

The answer is a. (Hardman, p 224.) Epinephrine is the drug of choice to relieve the symptoms of an acute, systemic, immediate hypersensitivity reaction to an allergen (anaphylactic shock). Subcutaneous administration of a 1 1000 solution of epinephrine rapidly relieves itching and urticaria, and this may save the life of the patient when laryngeal edema and bronchospasm threaten suffocation and severe hypotension and cardiac arrhythmias become life-endangering. Norepinephrine, isoproterenol, and atropine are ineffective therapies Angioedema is responsive to antihis-... 

Vasoconstriction. Local application of a-sympathomimetics can be employed in infiltration anesthesia (p. 204) or for nasal decongestion (naphazoline, tetra-hydrozoline, xylometazoline pp. 90, 324). Systemically administered epinephrine is important in the treatment of anaphylactic shock for combating hypotension. 

IgE-mediated allergic reactions (p. 72) involve mast cell release of histamine (p. 114) and production of other mediators (such as leukotrienes, p. 196). Resultant responses include relaxation of vascular smooth muscle, as evidenced locally by vasodilation (e.g., conjunctival congestion) or systemically by hypotension (as in anaphylactic shock) enhanced capillary permeability with transudation of fluid into tissues— swelling of conjunctiva and mucous membranes of the upper airways ( hay fever ), cutaneous wheal formation contraction of bronchial smooth muscle-bronchial asthma stimulation of intestinal smooth musde—diarrhea. 

PAF is also a lipid mediator of anaphylactic responses. PAF produced by anti-IgE challenge of IgE-sensitized basophils results in degranulation and histamine release. PAF can induce rapid and shallow breathing, transient apnea, and edema in the respiratory system. In the cardiovascular system, PAF directly induces bradycardia, hypotension, elevated right ventricular pressure, vascular spasms, and increased vascular permeability. 

Other possibly associated systemic symptoms include dizziness, nausea and headache. Rhinorrhea, bronchospasms or gastrointestinal symptoms are less frequent, and hypotension or anaphylactic shock are very rare. There is an increased incidence of atopy (45.5%) (Zuberbier et al. 1994) and of bronchial reactivity on provocation (Czarnetzki et al. 1984a). Other types of urticaria can coexist, although they are not particularly frequent (Henz et al. 1997). 

An unusual acute anaphylactic-like syndrome that resembles septic shock has been observed in some HIV-infected patients following the administration of co-trimoxazole. The severe systemic reaction is characterized by fever, hypotension, and pulmonary infiltrates, but absence of bron-chospasm and laryngeal edema are points of difference with classic anaphylaxis. Because of the similarities between this hypotensive syndrome and septic shock, it has been suggested that tumor necrosis factor (TNF), a mediator of septic shock, is released during episodes of the syndrome. However, TNF and IgE antibodies to co-trimoxazole were not detected and there was no depression of complement in a patient who responded with a second episode of shock after being rechallenged with the drug combination. 

Central nervous system fatigue, fever, headache, insomnia, somnolence, psychosis, seizure Endocrine and metabolic hypophosphatemia, hypokalemia/hyperkalemia, hypomagnesemia, hypocalcemia, hypernatremia, hypothyroidism Cardiovascular atrial fibrillation/flutter, hypertension/hypotension, syncope, tachycardia, CHF, edema, anaphylactic shock Gastrointestinal nausea, vomiting, anorexia, abdominal pain, dyspepsia, constipation, gastrointestinal bleeding, diarrhea, stomatitis Genitourinary UTI... 

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