Racephedrine in combination with theophylline, phenobarbital was used to treat bronchial asthma. However, its application was substituted more effective agent. In addition, FDA has reviewed the final monograph for over-the-counter bronchodilator drug products to add additional warnings and to revise the indications in the labeling of products containing racephedrine hydrochloride.

Propylhexedrine is considered to be an agonist of alpha-adrenergic receptors. It is effective as a topical vasoconstrictor. The primary medicinal use of Benzedrex (Propylhexedrine inhaler) propylhexedrine is temporary symptomatic relief of nasal decongestion due to colds, allergies and allergic rhinitis. Structurally and pharmacologically related to amphetamine.Exact mechanism of action unknown but thought to be similar to amphetamine. When used as a nasal inhaler for this indication, propylhexedrine reduces nasal airway resistance without producing rebound congestion. Abuse does not occur by nasal inhalation; however, a small amount of abuse of the propylhexedrine containing nasal inhalers occurs by oral ingestion of the contents of the inhaler or by intravenous injection. Propylhexedrine is a central nervous system (CNS) stimulant of low abuse potential, a stimulant of low preference for stimulant abusers compared with amphetamine, methylphenidate, phenmetrazine.

Ephedrine (l-form) is an alkaloid, which was initially purified from Ephedra plant. The extract form Ephedra has been used in China for medicinal purposes for several thousand years. Ephedrine acts as an agonist at alpha- and beta-adrenergic receptors and indirectly causes the release of norepinephrine from sympathetic neurons. The drug crosses the blood brain barrier and stimulates the central nervous system. Ephedrine products are now banned in many countries, as they are a major source for the production of the addictive compound methamphetamine. FDA has approved ephedrine only for the treatment of clinically important hypotension occurring in the setting of anesthesia.

Pseudoephedrine is a sympathomimetic drug. Pseudoephedrine acts as an adrenomimetic and inhibitor of monoamine transporters. Ephedra sinica, a species of ephedra (ma huang), contains ephedrine and pseudoephedrine. Ephedra has been found to stimulate the nervous system, increase airflow into the lungs and constrict blood vessels. In combination with caffeine, ephedra appears to cause weight loss. Pseudoephedrine is a decongestant that shrinks blood vessels in the nasal passages. Pseudoephedrine is used to relieve nasal or sinus congestion caused by the common cold, sinusitis, and hay fever and other respiratory allergies.

Pseudoephedrine is a sympathomimetic drug. Pseudoephedrine acts as an adrenomimetic and inhibitor of monoamine transporters. Ephedra sinica, a species of ephedra (ma huang), contains ephedrine and pseudoephedrine. Ephedra has been found to stimulate the nervous system, increase airflow into the lungs and constrict blood vessels. In combination with caffeine, ephedra appears to cause weight loss. Pseudoephedrine is a decongestant that shrinks blood vessels in the nasal passages. Pseudoephedrine is used to relieve nasal or sinus congestion caused by the common cold, sinusitis, and hay fever and other respiratory allergies.

Racephedrine in combination with theophylline, phenobarbital was used to treat bronchial asthma. However, its application was substituted more effective agent. In addition, FDA has reviewed the final monograph for over-the-counter bronchodilator drug products to add additional warnings and to revise the indications in the labeling of products containing racephedrine hydrochloride.

Xylometazoline, also spelled xylomethazoline, is a medication which is used to improve symptoms of nasal congestion, allergic rhinitis, and sinusitis. Xylometazoline was patented in 1956 and came into medical use in 1959. It is on the World Health Organization's List of Essential Medicines, the most effective and safe medicines needed in a health system. The drug works by stimulating adrenergic receptors on the lamina propria of blood vessels in the nose. The decongestant effect is due to constriction of large veins in the nose which swell up during the inflammation of any infection or allergy of the nose. The smaller arteries are also constricted and this causes the colour of the nasal epithelium to be visibly paler after dosage. The standard adult solution strength is 0.1% w/v xylometazoline (or 1 mg per 1 mL solution), and the dose for children under 12 is usually 0.05% (0.5 mg/mL).