Hexylcaine hydrochloride, a benzoic acid ester, is a local anaesthetic that has been used for surface anaesthesia of mucous membranes. Local anesthetics produce a transient block of nerve conduction by interfering with sodium channels. This effect of the anesthetic interferes with the development of an action potential across the nerve.

Dihydroergocristine is an ergot alkaloid that has an partial agonist activity on dopaminergic and alpha-adrenergic receptors and antagonist activity on serotonin receptors. The drug was approved by FDA in combination with other alkaloids (dihydroergocornine, dihydro-alpha-ergocryptine and dihydro-beta-ergocryptine mesylate salts) under the name Hydergine for the treatment of dimentia and cerebrovascular insufficiency.

Cyclomethycaine (also known as Surfacaine) is a local anesthetic.

Cyclomethycaine (also known as Surfacaine) is a local anesthetic.

Antazoline is an antagonist of histamine H1 receptors. It selectively bind to but does not activate histamine H1 receptors, thereby blocking the actions of endogenous histamine, which subsequently leads to temporary relief of the negative symptoms brought on by histamine. Antazoline in combination with naphazoline (VASOCON-A®) is indicated to relieve the symptoms of allergic conjunctivitis.

Tripelennamine (sold as Pyribenzamine by Novartis) is a drug that is used as an antipruritic and first-generation antihistamine. Histamine acting on H1-receptors produces vasodilatation, hypotension, flushing, headache, tachycardia, and bronchoconstriction. Histamine also increases vascular permeability and potentiates pain. Tripelennamine can be used in the treatment of asthma, hay fever, rhinitis, and urticaria, but is now less common as newer antihistamines have replaced it.

Tolazoline, also known as priscoline, was used in treatment of persistent pulmonary hypertension of the newborn. But that prescription was discontinued. Priscoline given intravenously produces vasodilatation, primarily due to a direct effect on vascular smooth muscle, and cardiac stimulation; the blood pressure response depends on the relative contributions of the two effects. Priscoline usually reduces pulmonary arterial pressure and vascular resistance. The mechanisms of its therapeutic effects are not clear, but is known, that tolazoline is a non-selective competitive α-adrenergic receptor antagonist and it possesses histamine agonist activity.

Tripelennamine (sold as Pyribenzamine by Novartis) is a drug that is used as an antipruritic and first-generation antihistamine. Histamine acting on H1-receptors produces vasodilatation, hypotension, flushing, headache, tachycardia, and bronchoconstriction. Histamine also increases vascular permeability and potentiates pain. Tripelennamine can be used in the treatment of asthma, hay fever, rhinitis, and urticaria, but is now less common as newer antihistamines have replaced it.

Etafedrine, a sympathomimetic agent that acts on the sympathetic receptors of the bronchial tree relaxing spasm in a manner similar to that of ephedrine, is a bronchodilator and a selective β2-adrenoreceptor agonist. Contraction of the guinea pig tracheal chain by acetylcholine or histamine was antagonized by etafedrine with a higher potency then ephedrine but with a lower potency than epinephrine (adrenaline). Etafedrine did not increase heart rate or force of contraction in guinea pig atria. Unlike ephedrine and tyramine, etafedrine did not induce the release of noradrenaline as was demonstrated in vitro in the perfused rabbit heart and instead acted as a selective β2 adrenoreceptor agonist. Etafedrine also belongs to the family of medications called decongestants. It works by narrowing blood vessels in the nasal passages, helping to relieve nasal stuffiness. Etafedrine has been used in pharmaceutical compositions, such as NETHAPRIN Expectorant, Nethaprin Dospan and Dalmacol, useful in the treatment of asthma and other respiratory disorders including chronic bronchitis.