Chronic obstructive pulmonary disease respiratory stimulants

Theophylline reduces contractile activity of smooth musculature, widens bronchi and blood vessels, reduces pulmonary vascular resistance, stimulates the respiratory center, and increases the frequency and power of cardiac contractions. It is used for bronchial asthma, preventing attacks, and systematic treatment. Theophylline is also used for symptomatic treatment of bronchospastic syndrome of a different etiology (chronic obstructive pulmonary disease, chronic bronchitis, and pulmonary emphysema). A large number of combined drags are based on theophylline. Synonyms of theophylline are adophyllin, asthmophyllin, theocin, and many others. 

As indicated, most of the analeptic stimulants were used as pharmacological treatments for overdosage of CNS depressants. Doxapram (Dopram) is sometimes used to counteract postanesthetic respiratory depression and as an aid in chronic obstructive pulmonary disease. Pentylenetetrazol (Metrazol) was used experimentally on rare occasions to activate the electroencephalogram. Strychnine is used almost exclusively in animal studies as a tool for studying CNS mechanisms because it is a relatively specific glycine antagonist. 

Almitrine is a respiratory stimulant that improves hypoxemia in about 80% of patients with severe chronic obstructive pulmonary disease (SEDA-17, 212). Oral almitrine bimesilate (100 mg/day) increased Pa02 in patients with severe chronic obstructive pulmonary disease without altering mean pulmonary artery pressure (1). Adverse effects were rarely observed and it was concluded that long-term treatment was safe. In other studies, respiratory, digestive, and neurological symptoms have been noted but were often pre-existent (2,3). 

Doxapram (0.5 to 1 mg/kg) is used as a postanesthesia respiratory stimulation, in drug-induced CNS depression, and in acute hypercapnia associated with chronic obstructive pulmonary disease. 

Doxapram is an analeptic that increases the depth of respirations (tidal volume) by stimulating the respiratory center in CNS respiratory rate may increase slightly. It may elevate BP by increasing cardiac output. Respiratory depression from opiates is reversed without affecting pain relief. It is indicated when one requires the stimulation of deep breathing in postoperative patients for reversal of respiratory depression caused by anesthesia (other than muscle relaxants) or drug overdose and as a temporary measure in acute respiratory failure in patients with chronic obstructive pulmonary disease (COPD) who are not undergoing mechanical ventilation. 

Abbreviations-. TCEMS, transcutaneous electrical muscle stimulation CHF, congestive heart failure COPD, chronic obstructive pulmonary disease Vo2max, peak oxygen consumption NYHA, New York heart association CSA, cross-sectional area Wmax, maximal workload CRQ, chronic respiratory disease questionnaire. 

Pharmacology The methyixanthines (theophylline, its soluble salts and derivatives) directly relax the smooth muscle of the bronchi and pulmonary blood vessels, stimulate the CNS, induce diuresis, increase gastric acid secretion, reduce lower esophageal sphincter pressure, and inhibit uterine contractions. Theophylline is also a central respiratory stimulant. Aminophylline has a potent effect on diaphragmatic contractility in healthy people and may then be capable of reducing fatigability and thereby improve contractility in patients with chronic obstructive airways disease. Pharmacokinetics ... 

More broadly, timolol therapy should be considered with caution in patients with any significant sign, symptom, or history for which systemic beta-blockade would be medically imwise.This includes disorders of cardiovascular or respiratory origin (e g., asthma, chronic bronchitis, and emphysema) as well as many other conditions. Spirometric evaluation after institution of timolol therapy may help to identify patients in whom bronchospasm develops after commencement of therapy. In general, however, patients with asthma and other obstructive pulmonary diseases should avoid this drug. Sympathetic stimulation may be essential to support the circulation in individuals with diminished myocardial contractility, and its inhibition by P-adrenoceptor antagonists may precipitate more severe cardiac feilure. 

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