Pilocarpine is an imidazole alkaloid that is used to lower the intraocular pressure associated with glaucoma. This drug belongs to the group of parasympathomimetics and is applied topically to the eye, specifically to the conjunctival sac. Sometimes it is also used in the form of drops under the tongue to increase salivation, and as an antidote in atropine poisoning.

Contents:

  1. Polycarpine - how does it work?
  2. Pilocarpine in ophthalmology
  3. Polycarpine - contraindications for use
  4. Pilocarpine - side effects
  5. Polycarpine - overdose

Pilocarpineis obtained from the leaves of the potplant shrub. Potoślin jaborandi ( Pilocarpus jaborandi ) - this is a species of trees from the rutaceae family that comes from the tropical forests of Brazil.

For pharmaceutical purposes, leaves of the jaborandi pot plant are used, as well as related species, such asPilocarpus microphyllusandPilocarpus pennatifolius . The harvested leaves are then dried naturally.

Polycarpine - how does it work?

Pilocarpine has a parasympathomimetic effect - which means that it stimulates the parasympathetic system. Parasympathomimetics stimulate cholinergic receptors that are present on the surface of cells, including nerve cells.

Pilocarpine acts on muscarinic receptors, which are a subtype of cholinergic receptors. This substance greatly enhances the secretion of:

  • sweat
  • tears
  • saliva
  • of mucus in the respiratory tract
  • also increases the secretory functions of the glands of the stomach, pancreas and intestines
  • causes the pupil sphincter to contract, which narrows it and lowers the intraocular pressure

Pilocarpine in ophthalmology

Once in the eye, pilocarpine works in different ways. By causing the pupil sphincter to contract, it makes the pupil narrower. It also acts on the longitudinal bundles of the ciliary muscle, which also causes them to contract - this in turn pulls the scleral spur backward and stretches the trabecular weave in the trabecular angle.

As a result, the resistance to outflow of aqueous humor in the corneal-iris angle decreases and, importantly, the intraocular pressure drops.

Pointing toThe use of pilocarpine is the treatment of primary open-angle and angle-closure glaucoma, and it is also used in the acute attack of angle-closure glaucoma.

How fast does pilocarpine work? Applied locally, it narrows the pupil about 15-30 minutes after instillation. Its effect lasts for the next 4-8 hours. The maximum reduction in intraocular pressure takes place 2-4 hours after instillation and lasts for the next 8-12 hours.

Note! It should be remembered that pilocarpine can reduce visual acuity, therefore people who drive vehicles or operate mechanical devices should be especially careful in the dark - in the evening and at night.

It is also worth paying attention to the method of application. If, in addition to pilocarpine, we also use other ophthalmic drugs, remember to keep a few, or even better, a dozen or so minutes interval between the application of successive preparations and adhere to the principle that ointments and gels should be applied at the end, unless your doctor tells you otherwise.

People wearing contact lenses should remove them before applying the drug and put them on at the earliest 15 minutes after application.

Pilocarpine can dry out the eyes, which can be felt especially by contact lens wearers - so it may be advisable to use moisturizing eye drops.

Pilocarpine - contraindications to use

There are ailments and ailments that are a contraindication to using pilocarpine or changing its dose. People with:

should be especially careful
  • severe heart failure
  • corneal damage
  • bronchial asthma
  • urination disorders due to obstruction of the urinary tract
  • peptic ulcer of the stomach and / or duodenum
  • hypertension
  • Parkinson's disease

People who are prescribed pilocarpine should undergo a fundus examination, which is essential especially in patients with retinal diseases, as they are at risk of retinal detachment. In turn, people with glaucoma who use pilocarpine should regularly check the intraocular pressure and the field of vision of an ophthalmologist.

Tonometry - intraocular pressure test

Perimetry is the study of the field of view. What is it?

Pilocarpine - side effects

Like all drugs, pilocarpine can also cause some side effects, although they do not occur in all patients using this drug.

Most common activitiesundesirable are the local ones related to the eye area:

  • corneal irritation (burning, stinging, eye pain, photophobia)
  • conjunctival redness, lacrimation, night blindness
  • accommodation disorders (myopia)
  • retinal detachment (especially in people with myopia)
  • vitreous hemorrhages and lens opacities (especially in long-term use)

In addition, systemic side effects may occur, such as:

  • headaches
  • dizziness
  • bradycardia
  • hypotension
  • salivation
  • vomiting
  • nausea
  • diarrhea
  • excessive sweating
  • bronchospasm

In order to somehow limit the systemic absorption of the active substance, it is recommended to compress the tear duct in the medial corner of the eye for 1 minute immediately after instillation. It should be added, however, that systemic side effects appear relatively rarely.

However, as soon as a patient notices any unpleasant symptoms or ailments, he should consult a doctor immediately. It may be necessary to modify the dose or completely change the drug.

Polycarpine - overdose

Excess drug - in the case of instillation of too much of it - should be rinsed from the conjunctival sac with boiled water at room temperature as soon as possible, while if you accidentally ingest pilocarpine, drink 150-200 ml of water, induce vomiting and go to the hospital for gastric lavage

Overdosing the recommended doses (especially after accidentally drinking the drug) may cause symptoms such as:

  • increased secretion of tears, saliva, sweat, gastric juice
  • slow heart rate
  • decrease blood pressure

If you experience side effects after taking too much pilocarpine, you may need to treat yourself with anticholinergic agents (e.g. atropine).

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