Centrally acting respiratory stimulants

Amphetamine stirrmlates the respiratory center, increasing the rate and depth of respiration. In normal individuals, usual doses of the drug do not appreciably increase respiratory rate or minute volume. Nevertheless, when respiration is depressed by centrally acting drugs, amphetamine may stimulate respiration. 

Respiratory stimulation may be caused by several mechanisms. Some agents act directly on the respiratory center and thus are central respiratory... 

The sympathomimetics can act on the respiration by several mechanisms. The respiratory stimulation which they provoke corresponds to a central effect and particularly to an excitation of the respiratory center in the case of benzedrine, Pervitin, and ephedrine. 

Xanthine derivatives have a number of pharmacological properties in common. Five major actions are observed (1) central nervous system and respiratory stimulation, (2) skeletal muscle stimulation, (3) diuresis, (4) cardiac stimulation, and (5) smooth-muscle relaxation. Caffeine (29) increases central nervous system activity and its main effect is on the cerebral cortex, where it acts to produce clear thought and reduce drowsiness and fatigue. The normal dose is 100-200 mg (Cordell, 1981). The oral LD50 in mouse is 127-137 mg/kg the oral LD50 in rat for theobromine (31) is 950... 

Cocaine. This lias a bitter taste, is mydriatic, produces local anaesthesia and is toxic. After absorption, or when taken internally, it acts chiefly by stimulation of the central nervous system, succeeded by depression. Since the two phases may be present in different areas simultaneously, a mixed result may ensue. With large doses the chief symptoms are those of medullary depression. Death is due to paralysis of the respiratory centre. The main use of cocaine in medicine is as a local anaesthetic. 

Heroin s primary toxic principle is its profound ability to depress the central nervous system (CNS). Opioid analgesics bind with stereospecific receptors at many sites within the CNS. Heroin, similar to other opioids, exerts its pharmacologic effect by acting at mu, kappa, and delta receptors in the brain. Although the precise sites and mechanisms of action have not been fully determined, alterations in the release of various neurotransmitters from afferent nerves sensitive to painful stimuli may be partially responsible for the analgesic effect. Activities associated with the stimulation of opiate receptors are analgesia, euphoria, respiratory depression, miosis, and reduced gastrointestinal motility. 

It was Chen and Schmidt (154) who deserved the credit for the extensive pharmacodynamic studies of ephedrine which resulted in its introduction into therapeutics (155). Ephedrine acts both centrally and peripherally. It is a stimulant of the respiratory center and it resembles caffeine in this respect. Its influence on the respiratory tract is due wholly to peripheral actions (156). 

Caffeine is a potent central stimulant. It also acts on the cardiac muscle and on the kidneys. It stimulates the higher centres of the CNS thereby causing enhanced mental alertness and wakefulness. Caffeine helps in the stimulation of respiratory centres. Its diuretic action is due to enhanced glomerular filtration rate, increased renal blood flow and above all the reduction of the normal tubular reabsorption. 

Have you ever wondered about the origin of the saying, it s a bitter piii to swaiiow This saying is used to describe a situation that is difficuit to accept. Many medications contain bases, and a bitter taste is a property of bases. So, many medications actually have a bitter taste. If you look at the chemical formulas of the components of medications, you will see that they often contain nitrogen. One such component is caffeine, which acts as a stimulant on the central nervous and respiratory systems. Its molecular formula is C8Hio02N4- ammonia, caffeine has basic properties because it has a nitrogen that can accept a proton. 

Drugs with stimulating effect on the central nervous system acting on circulatory and respiratory centra in the medulla. 

Pharmacologically, the action of the various bacterial toxins is specific for each individual toxin. In the case of botulinus and tetanus toxins, action seems to be restricted to brain or nerve tissue. Bishop and Bronfenbrenner (11) state that botulinus toxin has a curare-like action and that the toxin is specific for the myoneural jimctions. Death in animals is due to respiratory paralysis. By means of artificial respiration, these authors and more recently Legroux and Levaditi (79) have been able to prolong the life of intoxicated animals for a considerable length of time. The pharmacological action of tetanus toxin is still a controversial question. Two main hypotheses have been summarized by Topley and Wilson (135) as follows (I) That the toxin is absorbed by the motor nerve endings and carried up the axis cylinders to the anterior horn cells of the central nervous system, which are then stimulated to produce muscular contractions and 2) that the toxin acts locally on the motor nerve endings and centrally on the anterior horn cells, which it reaches via the lymphatic vessels and the blood stream. ... 

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