Trimethaphan (or Trimethaphan camsylate), a ganglionic blocking agent and an antihypertensive drug, was marketed under the brand name Arfonad. Arfonad is indicated to induce systemic arterial hypotension in patients undergoing major surgery and to treat severe systemic hypertension, and in the emergency treatment of pulmonary edema in patients with pulmonary hypertension associated with systemic hypertension. Trimethaphan prevents stimulation of postsynaptic receptors by competing with acetylcholine for these receptor sites. Additional effects may include direct peripheral vasodilation and release of histamine. This drug was discontinued because of the competition from newer drugs that are more selective in their actions and effects.

Thiamylal is a barbiturate that is administered intravenously for the production of complete anesthesia of short duration, for the induction of general anesthesia, or for inducing a hypnotic state. Thiamylal, a barbiturate, is used in combination with acetaminophen or aspirin and caffeine for its sedative and relaxant effects in the treatment of tension headaches, migraines, and pain. Barbiturates act as nonselective depressants of the central nervous system (CNS), capable of producing all levels of CNS mood alteration from excitation to mild sedation, hypnosis, and deep coma. In sufficiently high therapeutic doses, barbiturates induce anesthesia. Thiamylal binds at a distinct binding site associated with a Cl- ionopore at the GABAA receptor, increasing the duration of time for which the Cl- ionopore is open. The post-synaptic inhibitory effect of GABA in the thalamus is, therefore, prolonged.

Tridihexethyl is a synthetic anticholinergic agent which was marketed under the brand name Pathilon as an adjunct in the treatment of peptic ulcer disease. However, it is no longer available in the US market. Tridihexethyl may block all three types of muscarinic receptors including M-1 receptors in the CNS and ganglia, M-2 receptors in the heart, and M-3 receptors. The muscarinic acetylcholine receptors mediate various cellular responses including inhibition of adenylate cyclase, the breakdown of phosphoinositides, and modulation of potassium channels through the action of G proteins. Tridihexethyl inhibits vagally mediated reflexes by antagonizing the action of acetylcholine. This, in turn, reduces the secretion of gastric acids in the stomach. Tridihexethyl was also examined for effect on patients with acquired nystagmus where four out of six patients showed improvement, but due to the profile usage of Tridihexethyl to treat nystagmus was limited.

Buclizine, a piperazine derivative, is a sedating antihistamine with antimuscarinic and moderate sedative action. The drug is used mainly for its antiemetic action, particularly in the prevention of motion sickness, and in the treatment of migraine in combination with analgesics. The following side/adverse effects have been selected on the basis of their potential clinical significance: drowsiness; Incidence less frequent; blurred vision; dryness of mouth, nose, and throat; headache; nervousness, restlessness, or trouble in sleeping; upset stomach. The following drug interactions have been selected on the basis of their potential clinical significance: alcohol; anticholinergics or other medications with anticholinergic activity; apomorphine.

Digoxin is a cardiac glycoside derived from the purple foxglove flower. In 1785, the English chemist, botanist, and physician Sir William Withering published his findings that Digitalis purpurea could be used to treat cardiac dropsy (congestive heart failure; CHF). Digoxin has been in use for many years, but was not approved by the FDA for treatment of heart failure (HF) until the late 1990s. Another FDA indication for digoxin is atrial fibrillation (AF). Digoxin also has numerous off-label uses, such as in fetal tachycardia, supra-ventricular tachycardia, cor pulmonale, and pulmonary hypertension. Digitoxin inhibits the Na-K-ATPase membrane pump, resulting in an increase in intracellular sodium and calcium concentrations. Increased intracellular concentrations of calcium may promote activation of contractile proteins (e.g., actin, myosin). Digoxin also has Para sympathomimetic properties. By increasing vagal tone in the sinoatrial and atrioventricular (AV) nodes, it slows the heart rate and AV nodal conduction.

BETAZOLE is a histamine H2 receptor agonist used clinically to test gastric secretory function.

Iodipamide is used as a contrast agent for cholecystography and intravenous cholangiography. Following intravenous administration of Cholografin Meglumine, iodipamide is carried to the liver where it is rapidly secreted. The contrast medium appears in the bile within 10 to 15 minutes after injection, thus permitting visualization of the hepatic and common bile ducts, even in cholecystectomized patients. Iodipamide (Cholografin Meglumine) is indicated for intravenous cholangiography and cholecystography as follows: (a) visualization of the gallbladder and biliary ducts in the differential diagnosis of acute abdominal conditions, (b) visualization of the biliary ducts, especially in patients with symptoms after cholecystectomy, and (c) visualization of the gallbladder in patients unable to take oral contrast media or to absorb contrast media from the gastrointestinal tract. The biliary ducts are readily visualized within about 25 minutes after administration, except in patients with impaired liver function. The gallbladder begins to fill within an hour after injection; maximum filling is reached after two to two and one-half hours. Organic iodine compounds block x-rays as they pass through the body, thereby allowing body structures containing iodine to be delineated in contrast to those structures that do not contain iodine. The degree of opacity produced by these iodinated organic compounds is directly proportional to the total amount (concentration and volume) of the iodinated contrast agent in the path of the x-rays. Iodipamide's primary excretion through the hepato-biliary system and concentration in bile allows visualization of the gallbladder and biliary ducts.

AZAPETINE, a benzazepine derivative, is an alpha-1 adrenoceptor antagonist. It is a potent arterial vasodilator in the treatment of peripheral vascular diseases.

Pentolinium (brand name Ansolysen) is a ganglionic cholinergic antagonist, acting on alpha 3 beta 4 neuronal nicotinic acetylcholine receptors (nAChRs). It was used as an antihypertensive drug during surgery or to control hypertensive crises, but Ansolysen was discontinued. Pentolinium inhibits release of adrenaline and noradrenaline from adrenergic nerves.

AZAPETINE, a benzazepine derivative, is an alpha-1 adrenoceptor antagonist. It is a potent arterial vasodilator in the treatment of peripheral vascular diseases.