Duration
Duration - General Information
An alpha-adrenergic agonist used as a mydriatic, nasal decongestant, and cardiotonic agent. [PubChem]
Pharmacology of Duration
Duration is a powerful vasoconstrictor. It is used as a mydriatic, nasal decongestant, and cardiotonic agent. Duration is a postsynaptic alpha-receptor stimulant with little effect on the beta receptors of the heart. Parenteral administration of Duration causes a rise in systolic and diastolic pressures, cardiac output is slightly decreased and peripheral resistance is considerably increased, most vascular beds are constricted; renal, splanchnic, cutaneous, and limb blood flows are reduced but coronary blood flow is increased. Pulmonary vessels are constricted, and pulmonary arterial pressure is raised. This alpha receptor sympathetic agonist is also used locally because its vasoconstrictor and mydriatic action.
Duration for patients
Duration Interactions
Vasopressors, particularly metaraminol, may cause serious cardiac arrhythmias during halothane anesthesia and therefore should be used only with great caution or not at all.
MAO Inhibitors
The pressor effect of sympathomimetic pressor amines is markedly potentiated in patients receiving monoamine oxidase inhibitors (MAOI). Therefore, when initiating pressor therapy in these patients, the initial dose should be small and used with due caution. The pressor response of adrenergic agents may also be potentiated by tricyclic antidepressants.
Duration Contraindications
Phenylephrine hydrochloride should not be used in patients with severe hypertension, ventricular tachycardia, or in patients who are hypersensitive to it or to any of the components.
Additional information about Duration
Duration Indication: For the treatment of ophthalmic disorders (hyperaemia of conjunctiva, posterior synechiae, acute atopic), nasal congestion, hemorrhoids, hypotension, shock, hypotension during spinal anesthesia, paroxysmal supraventricular tachycardia. It is also used as an aid in the diagnosis of heart murmurs and for prolongation of spinal anesthesia
Mechanism Of Action: Duration produces its ophthalmic and systemic actions by acting on alpha 1 adrenergic receptors in the pupillary dilator muscle and the vascular smooth musle, resulting in contraction of the dilator muscle and contraction of the smooth muscle in the arterioles of the conjunctiva and peripheral vasoconstriction. Duration decreases nasal congestion by acting on alpha 1 adrenergic receptors in the arterioles of the nasal mucosa to produce constriction.
Drug Interactions: Not Available
Food Interactions: Not Available
Generic Name: Phenylephrine
Synonyms: Fenilefrina [Inn-Spanish]; L-Phenylephedrine; L-Phenylephrine; M-Methylaminoethanolphenol; M-Oxedrine; Metaoxedrinum; Metaoxedrine; Metaoxedrin; Metasynephrine; Phenylephrinum [Inn-Latin]
Drug Category: Adrenergic alpha-Agonists; Cardiotonic Agents; Nasal Decongestants; Sympathomimetics; Vasoconstrictor Agents; Mydriatics
Drug Type: Small Molecule; Approved
Other Brand Names containing Phenylephrine: Adrianol; AK-Dilate; AK-Nefrin; Alcon Efrin; Alconefrin Nasal Drops 12; Alconefrin Nasal Drops 25; Alconefrin Nasal Drops 50; Alconefrin Nasal Spray 25; Biomydrin; Dilatair; Dimetane; Dionephrine; Doktors; Duration; I-Phrine; Isophrim; Isophrin; Isopto Frin; M-Sympathol; M-Sympatol; M-Synephrine; Mesaton; Mesatone; Mesatonum; Metasympatol; Metsatonum; Mezaton; Minims Phenylephrine; Mydfrin; Neo-Synephrine; Neo-Synephrine Nasal Drops; Neo-Synephrine Nasal Jelly; Neo-Synephrine Nasal Spray; Neofrin; Neophryn; Neosynephrine; Nostril; Nostril Spray Pump; Nostril Spray Pump Mild; Ocu-Phrin Sterile Eye Drops; Ocugestrin; Phenoptic; Prefrin; Prefrin Liquifilm; Pyracort D; Relief Eye Drops for Red Eyes; Rhinall; Spersaphrine; Vicks Sinex; Visadron;
Absorption: Reduced bioavailability (compared to pseudoephedrine) following oral administration due to significant first-pass metabolism.
Toxicity (Overdose): Not Available
Protein Binding: 95% binding-plasma proteins
Biotransformation: Oral phenylephrine is extensively metabolised by monoamine oxidase, an enzyme which is present in the stomach and liver.
Half Life: 2.1 to 3.4 hours
Dosage Forms of Duration: Solution Intravenous
Ointment Topical
Liquid Intravenous
Strip Oral
Tablet Oral
Liquid Ophthalmic
Solution / drops Ophthalmic
Liquid Intramuscular
Chemical IUPAC Name: 3-[(1R)-1-hydroxy-2-methylaminoethyl]phenol
Chemical Formula: C9H13NO2
Phenylephrine on Wikipedia: https://en.wikipedia.org/wiki/Phenylephrine
Organisms Affected: Humans and other mammals
