Pirbuterol (trade name Maxair) is a short-acting β2 adrenoreceptor agonist with bronchodilating action used in the treatment of asthma. The pharmacologic effects of beta-adrenergic agonist drugs, including pirbuterol, are at least in proof attributable to stimulation through beta-adrenergic receptors of intracellular adenyl cyclase, the enzyme which catalyzes the conversion of adenosine triphosphate (ATP) to cyclic-adenosine monophosphate (c-AMP). Increased c-AMP levels are associated with relaxation of bronchial smooth muscle and inhibition of release of mediators of immediate hypersensitivity from cells, especially from mast cells. Pirbuterol is used in asthma for reversal of acute bronchospasm, and also as a maintenance medication to prevent future attacks. It should be used in patients 12 years of age and older with or without concurrent theophylline and/or inhaled corticosteroid. After inhalation of doses up to 800 μg (twice the maximum recommended dose) systemic blood levels of pirbuterol are below the limit of assay sensitivity (2–5 ng/ml). A mean of 51% of the dose is recovered in urine as pirbuterol plus its sulfate conjugate following administration by aerosol. Pirbuterol is not metabolized by catechol-O-methyltransferase.

Pirbuterol (trade name Maxair) is a short-acting β2 adrenoreceptor agonist with bronchodilating action used in the treatment of asthma. The pharmacologic effects of beta-adrenergic agonist drugs, including pirbuterol, are at least in proof attributable to stimulation through beta-adrenergic receptors of intracellular adenyl cyclase, the enzyme which catalyzes the conversion of adenosine triphosphate (ATP) to cyclic-adenosine monophosphate (c-AMP). Increased c-AMP levels are associated with relaxation of bronchial smooth muscle and inhibition of release of mediators of immediate hypersensitivity from cells, especially from mast cells. Pirbuterol is used in asthma for reversal of acute bronchospasm, and also as a maintenance medication to prevent future attacks. It should be used in patients 12 years of age and older with or without concurrent theophylline and/or inhaled corticosteroid. After inhalation of doses up to 800 μg (twice the maximum recommended dose) systemic blood levels of pirbuterol are below the limit of assay sensitivity (2–5 ng/ml). A mean of 51% of the dose is recovered in urine as pirbuterol plus its sulfate conjugate following administration by aerosol. Pirbuterol is not metabolized by catechol-O-methyltransferase.

Bitolterol is a beta 2-adrenergic agonist. Since it in itself is biologically inactive, bitolterol is considered a pro-drug. When administered it is activated within the lung by esterase hydrolysis to the active compound colterol catecholamine N-t-butyl-arterenol. Bitolterol was marked under the name tornalate and was indicated to prevent and treat of reversible bronchospasm associated with asthma or chronic obstructive pulmonary diseases. But that drug was withdrawn from the market by Elan Pharmaceuticals in 2001.

Guanabenz, an antihypertensive agent for oral administration-, is an aminoguanidine derivative, 2,'6-dichlorobenzylideneamina-guanidine acetate. It is white to an almost white powder having not more than a slight odor. Sparingly soluble in water and in 0.1 N hydrochloric acid; soluble in alcohol and in propylene glycol. Guanabenz is an orally active central alpha-2 adrenergic agonist. Its antihypertensive action appears to be mediated via stimulation of central alpha-adrenergic receptors, resulting in a decrease of sympathetic outflow from the brain at the bulbar level to the peripheral circulatory system. In clinical trials, guanabenz acetate, given orally to hypertensive patients, effectively controlled blood pressure without any significant effect on glomerular filtration rate, renal blood flow, body fluid volume or body weight. The Myelin Repair Foundation and the National Institutes of Health (National Institute of Neurological Disorders and Stroke) are developing guanabenz for the treatment of multiple sclerosis. Unlike the currently available treatment for multiple sclerosis that suppresses the immune system, guanabenz, an FDA approved the drug for the treatment of high blood pressure, has a potential to reduce the loss of myelin by protecting and repairing myelin-producing cells in the brain from damage. Phase I development is underway in the US.

Guanadrel is a postganglionic adrenergic blocking agent. Uptake of guanadrel and storage in sympathetic neurons occurs via the norepinephrine pump or transporter. Guanadrel slowly displaces norepinephrine from its storage in nerve endings and thereby blocks the release of norepinephrine normally produced by nerve stimulation. The reduction in neurotransmitter release in response to sympathetic nerve stimulation, as a result of catecholamine depletion, leads to reduced arteriolar vasoconstriction, especially the reflex increase in sympathetic tone that occurs with a change in position. Guanadrel is used to treat and control hypertension.

Estramustine is an antineoplastic agent indicated in the palliative treatment of patients with metastatic and/or progressive carcinoma of the prostate. Estramustine is a combination of estradiol with nitrogen mustard. In vivo, the nitrogen-mustard moiety becomes active and participates in alkylation of DNA or other cellular components. This causes DNA damage in rapidly dividing cancerous cells leading to cell death and ideally, tumor shrinkage. Also, due to the drugs estrogen component, it can bind more selectively to active estrogen receptors. Used for the palliative treatment of patients with metastatic and/or progressive carcinoma of the prostate.

Estramustine is an antineoplastic agent indicated in the palliative treatment of patients with metastatic and/or progressive carcinoma of the prostate. Estramustine is a combination of estradiol with nitrogen mustard. In vivo, the nitrogen-mustard moiety becomes active and participates in alkylation of DNA or other cellular components. This causes DNA damage in rapidly dividing cancerous cells leading to cell death and ideally, tumor shrinkage. Also, due to the drugs estrogen component, it can bind more selectively to active estrogen receptors. Used for the palliative treatment of patients with metastatic and/or progressive carcinoma of the prostate.

Estramustine is an antineoplastic agent indicated in the palliative treatment of patients with metastatic and/or progressive carcinoma of the prostate. Estramustine is a combination of estradiol with nitrogen mustard. In vivo, the nitrogen-mustard moiety becomes active and participates in alkylation of DNA or other cellular components. This causes DNA damage in rapidly dividing cancerous cells leading to cell death and ideally, tumor shrinkage. Also, due to the drugs estrogen component, it can bind more selectively to active estrogen receptors. Used for the palliative treatment of patients with metastatic and/or progressive carcinoma of the prostate.

Saralasin is an angiotensin II analogue which was developed for the treatment of hypertension in 1970s. For many years saralasin was supposed to be angiotensin receptors blocker, but recent studies have revealed that its pharmacological action can be explained by agonistic behavior toward angiotensin II receptor. The drug was approved by FDA under the name Sarenin, however, it is no longer available on the market.

Estramustine is an antineoplastic agent indicated in the palliative treatment of patients with metastatic and/or progressive carcinoma of the prostate. Estramustine is a combination of estradiol with nitrogen mustard. In vivo, the nitrogen-mustard moiety becomes active and participates in alkylation of DNA or other cellular components. This causes DNA damage in rapidly dividing cancerous cells leading to cell death and ideally, tumor shrinkage. Also, due to the drugs estrogen component, it can bind more selectively to active estrogen receptors. Used for the palliative treatment of patients with metastatic and/or progressive carcinoma of the prostate.