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Trade names | Isopto Carpine, Salagen, Vuity, others |
AHFS/Drugs.com | Monograph |
MedlinePlus | a608039 |
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Routes of administration | Topical eye drops, by mouth |
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Elimination half-life | 0.76 hours (5 mg), 1.35 hours (10 mg) [3] |
Excretion | urine |
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ECHA InfoCard | 100.001.936 |
Chemical and physical data | |
Formula | C11H16N2O2 |
Molar mass | 208.261 g·mol−1 |
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Pilocarpine is a lactone alkaloid originally extracted from plants of the Pilocarpus genus. [4] It is used as a medication to reduce pressure inside the eye and treat dry mouth. [1] [5] As an eye drop it is used to manage angle closure glaucoma until surgery can be performed, ocular hypertension, primary open angle glaucoma, and to constrict the pupil after dilation. [1] [6] [7] However, due to its side effects, it is no longer typically used for long-term management. [8] Onset of effects with the drops is typically within an hour and lasts for up to a day. [1] By mouth it is used for dry mouth as a result of Sjögren syndrome or radiation therapy. [9]
Common side effects of the eye drops include irritation of the eye, increased tearing, headache, and blurry vision. [1] Other side effects include allergic reactions and retinal detachment. [1] Use is generally not recommended during pregnancy. [10] Pilocarpine is in the miotics family of medication. [11] It works by activating cholinergic receptors of the muscarinic type which cause the trabecular meshwork to open and the aqueous humor to drain from the eye. [1]
Pilocarpine was isolated in 1874 by Hardy and Gerrard and has been used to treat glaucoma for more than 100 years. [12] [13] [14] It is on the World Health Organization's List of Essential Medicines. [15] It was originally made from the South American plant Pilocarpus . [12]
Pilocarpine stimulates the secretion of large amounts of saliva and sweat. [16] It is used to prevent or treat dry mouth, particularly in Sjögren syndrome, but also as a side effect of radiation therapy for head and neck cancer. [17]
It may be used to help differentiate Adie syndrome from other causes of unequal pupil size. [18] [19]
It may be used to treat a form of dry eye called aqueous deficient dry eye (ADDE) [20]
Pilocarpine is sometimes used immediately before certain types of corneal grafts and cataract surgery. [21] [22] It is also used prior to YAG laser iridotomy. In ophthalmology, pilocarpine is also used to reduce symptomatic glare at night from lights when the patient has undergone implantation of phakic intraocular lenses; the use of pilocarpine would reduce the size of the pupils, partially relieving these symptoms.[ dubious – discuss ] The most common concentration for this use is pilocarpine 1%.[ citation needed ] Pilocarpine is shown to be just as effective as apraclonidine in preventing intraocular pressure spikes after laser trabeculoplasty. [23]
In 2021, the U.S. Food and Drug Administration (FDA) approved pilocarpine hydrochloride as an eyedrop treatment for presbyopia, age-related difficulty with near-in vision. It works by causing the pupils to constrict, increasing depth of field, similar to the effect of pinhole glasses. Marketed as Vuity, the effect lasts for more than 6 hours. [24] [25]
Pilocarpine is used to stimulate sweat glands in a sweat test to measure the concentration of chloride and sodium that is excreted in sweat. It is used to diagnose cystic fibrosis. [26]
Use of pilocarpine may result in a range of adverse effects, most of them related to its non-selective action as a muscarinic receptor agonist. Pilocarpine has been known to cause excessive salivation, sweating, bronchial mucus secretion, bronchospasm, bradycardia, vasodilation, and diarrhea. Eye drops can result in brow ache and chronic use in miosis. It can also cause temporary blurred vision or darkness of vision, temporary shortsightedness, hyphema and retinal detachment.
Pilocarpine is a drug that acts as a muscarinic receptor agonist. It acts on a subtype of muscarinic receptor (M3) found on the iris sphincter muscle, causing the muscle to contract - resulting in pupil constriction (miosis). Pilocarpine also acts on the ciliary muscle and causes it to contract. When the ciliary muscle contracts, it opens the trabecular meshwork through increased tension on the scleral spur. This action facilitates the rate that aqueous humor leaves the eye to decrease intraocular pressure. Paradoxically, when pilocarpine induces this ciliary muscle contraction (known as an accommodative spasm) it causes the eye's lens to thicken and move forward within the eye. This movement causes the iris (which is located immediately in front of the lens) to also move forward, narrowing the Anterior chamber angle. Narrowing of the anterior chamber angle increases the risk of increased intraocular pressure. [27]
Plants in the genus Pilocarpus are the only known sources of pilocarpine, and commercial production is derived entirely from the leaves of Pilocarpus microphyllus (Maranham Jaborandi). This genus grows only in South America, and Pilocarpus microphyllus is native to several states in northern Brazil. [28]
Pilocarpine is extracted from the leaves of Pilocarpus microphyllus in a multi-step process : the sample is moistened with dilute sodium hydroxide to transform the alkaloid into its free-base form then extracted using chloroform or a suitable organic solvant. Pilocarpine can then be further purified by re-extracting the resulting solution with aqueous sulfuric acid then readjusting the pH to basic using ammonia and a final extraction by chloroform. [29] [30] [31]
It can also be synthesized from 2-ethyl-3-carboxy-2-butyrolactone in a 8 steps process from the acyl chloride (by treatment with thionyl chloride) via a Arndt–Eistert reaction with diazomethane then by treatment with potassium phthalimide and potassium thiocyanate. [4]
Pilocarpine is available under several trade names such as: Diocarpine (Dioptic), Isopto Carpine (Alcon), Miocarpine (CIBA Vision), Ocusert Pilo-20 and -40 (Alza), Pilopine HS (Alcon), Salagen (MGI Pharma), Scheinpharm Pilocarpine (Schein Pharmaceutical), Timpilo (Merck Frosst), and Vuity (AbbVie).
Pilocarpine is used to induce chronic epilepsy in rodents, commonly rats, as a means to study the disorder's physiology and to examine different treatments. [32] [33] Smaller doses may be used to induce salivation in order to collect samples of saliva, for instance, to obtain information about IgA antibodies.
Pilocarpine is given in moderate doses (about 2 mg) to induce emesis in cats that have ingested foreign plants, foods, or drugs. One feline trial determined it was effective, even though the usual choice of emetic is xylazine.[ citation needed ]
Glaucoma is a group of eye diseases that can lead to damage of the optic nerve. The optic nerve transmits visual information from the eye to the brain. Glaucoma may cause vision loss if left untreated. It has been called the "silent thief of sight" because the loss of vision usually occurs slowly over a long period of time. A major risk factor for glaucoma is increased pressure within the eye, known as intraocular pressure (IOP). It is associated with old age, a family history of glaucoma, and certain medical conditions or the use of some medications. The word glaucoma comes from the Ancient Greek word γλαυκός, meaning 'gleaming, blue-green, gray'.
The aqueous humour is a transparent water-like fluid similar to blood plasma, but containing low protein concentrations. It is secreted from the ciliary body, a structure supporting the lens of the eyeball. It fills both the anterior and the posterior chambers of the eye, and is not to be confused with the vitreous humour, which is located in the space between the lens and the retina, also known as the posterior cavity or vitreous chamber. Blood cannot normally enter the eyeball.
Carbachol, also known as carbamylcholine and sold under the brand name Miostat among others, is a cholinomimetic drug that binds and activates acetylcholine receptors. Thus it is classified as a cholinergic agonist. It is primarily used for various ophthalmic purposes, such as for treating glaucoma, or for use during ophthalmic surgery. It is generally administered as an ophthalmic solution.
The ciliary body is a part of the eye that includes the ciliary muscle, which controls the shape of the lens, and the ciliary epithelium, which produces the aqueous humor. The aqueous humor is produced in the non-pigmented portion of the ciliary body. The ciliary body is part of the uvea, the layer of tissue that delivers oxygen and nutrients to the eye tissues. The ciliary body joins the ora serrata of the choroid to the root of the iris.
Intraocular pressure (IOP) is the fluid pressure inside the eye. Tonometry is the method eye care professionals use to determine this. IOP is an important aspect in the evaluation of patients at risk of glaucoma. Most tonometers are calibrated to measure pressure in millimeters of mercury (mmHg).
A red eye is an eye that appears red due to illness or injury. It is usually injection and prominence of the superficial blood vessels of the conjunctiva, which may be caused by disorders of these or adjacent structures. Conjunctivitis and subconjunctival hemorrhage are two of the less serious but more common causes.
The ciliary muscle is an intrinsic muscle of the eye formed as a ring of smooth muscle in the eye's middle layer, the uvea. It controls accommodation for viewing objects at varying distances and regulates the flow of aqueous humor into Schlemm's canal. It also changes the shape of the lens within the eye but not the size of the pupil which is carried out by the sphincter pupillae muscle and dilator pupillae.
Betaxolol is a selective beta1 receptor blocker used in the treatment of hypertension and angina. It is also a adrenergic blocker with no partial agonist action and minimal membrane stabilizing activity. Being selective for beta1 receptors, it typically has fewer systemic side effects than non-selective beta-blockers, for example, not causing bronchospasm as timolol may. Betaxolol also shows greater affinity for beta1 receptors than metoprolol. In addition to its effect on the heart, betaxolol reduces the pressure within the eye. This effect is thought to be caused by reducing the production of the liquid within the eye. The precise mechanism of this effect is not known. The reduction in intraocular pressure reduces the risk of damage to the optic nerve and loss of vision in patients with elevated intraocular pressure due to glaucoma.
Latanoprost, sold under the brand name Xalatan among others, is a medication used to treat increased pressure inside the eye. This includes ocular hypertension and open-angle glaucoma. Latanaprost is applied as eye drops to the eyes. Onset of effects is usually within four hours, and they last for up to a day.
Timolol is a beta blocker medication used either by mouth or as eye drops. As eye drops it is used to treat increased pressure inside the eye such as in ocular hypertension and glaucoma. By mouth it is used for high blood pressure, chest pain due to insufficient blood flow to the heart, to prevent further complications after a heart attack, and to prevent migraines.
Pilocarpus is a genus of about 13 species of plants belonging to the family Rutaceae, native to the Neotropics of South America. Various species are important pharmacologically as a source of the parasympathomimetic alkaloid pilocarpine. Many of the species have the common name jaborandi.
Ocular hypertension is the presence of elevated fluid pressure inside the eye, usually with no optic nerve damage or visual field loss.
Brimonidine is an α2 agonist medication used to treat open-angle glaucoma, ocular hypertension, and rosacea. In rosacea it improves the redness. It is used as eye drops or applied to the skin. It is also available in the fixed-dose combination medication brimonidine/timolol along with timolol maleate.
Apraclonidine (INN), also known under the brand name Iopidine, is a sympathomimetic used in glaucoma therapy. It is an α2 adrenergic receptor agonist and a weak α1 adrenergic receptor agonist.
Dorzolamide, sold under the brand name Trusopt among others, is a medication used to treat high pressure inside the eye, including in cases of glaucoma. It is used as an eye drop. Effects begin within three hours and last for at least eight hours. It is also available as the combination dorzolamide/timolol.
Levobunolol is a non-selective beta blocker. It is used topically in the form of eye drops to manage ocular hypertension and open-angle glaucoma.
A spasm of accommodation is a condition in which the ciliary muscle of the eye remains in a constant state of contraction. Normal accommodation allows the eye to "accommodate" for near-vision. However, in a state of perpetual contraction, the ciliary muscle cannot relax when viewing distant objects. This causes vision to blur when attempting to view objects from a distance. This may cause pseudomyopia or latent hyperopia.
The scleral spur in the visual system is a protrusion of the sclera into the anterior chamber. The spur is an annular structure composed of collagen in the human eye.
Secondary glaucoma is a collection of progressive optic nerve disorders associated with a rise in intraocular pressure (IOP) which results in the loss of vision. In clinical settings, it is defined as the occurrence of IOP above 21 mmHg requiring the prescription of IOP-managing drugs. It can be broadly divided into two subtypes: secondary open-angle glaucoma and secondary angle-closure glaucoma, depending on the closure of the angle between the cornea and the iris. Principal causes of secondary glaucoma include optic nerve trauma or damage, eye disease, surgery, neovascularization, tumours and use of steroid and sulfa drugs. Risk factors for secondary glaucoma include uveitis, cataract surgery and also intraocular tumours. Common treatments are designed according to the type and the underlying causative condition, in addition to the consequent rise in IOP. These include drug therapy, the use of miotics, surgery or laser therapy.
Ocular hypotony, or ocular hypotension, or shortly hypotony, is the medical condition in which intraocular pressure (IOP) of the eye is very low.
Ocular hypertension... alternative options include carbonic anhydrase inhibitors such as brinzolamide or dorzolamide, a topical sympathomimetic such as apraclonidine or brimonidine tartrate, or a topical miotic such as pilocarpine, given either as monotherapy or as combination therapy.
Pilocarpine is no longer routinely used for long term IOP control due to a poor side effect profile
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