PICO EYE DROPS (Each ml contains pilocerpine HCL 2%w/v

Indications

• Open-angle glaucoma
• Angle-closure glaucoma
• Xerostomia (dry mouth) due to radiotherapy or Sjögren's syndrome

Dosage

Children: Refer to the BNF for Children for appropriate dosing in paediatric populations.

Adults: Dosage varies based on the indication and formulation. Refer to the BNF for specific dosing guidelines.

Mechanism of action

Pilocarpine binds to muscarinic receptors in the body, particularly M3 receptors in the eye and salivary glands. This binding leads to increased secretion from the salivary glands and increased ciliary muscle contraction, facilitating drainage of the aqueous humor through the trabecular meshwork, ultimately lowering intraocular pressure.

Pharmacodynamics

Pilocarpine exhibits its effects by mimicking acetylcholine, leading to various parasympathetic effects such as increased exocrine gland secretion and contraction of smooth muscles. In glaucoma treatment, it enhances the outflow of aqueous humor, which is crucial for lowering intraocular pressure. Its action can lead to miosis (pupil constriction), which also contributes to improved drainage.

Pharmacokinetics

Pilocarpine is administered topically (as an eye drop) or orally. After topical administration, it penetrates the cornea and reaches the intraocular structures. The onset of action is rapid, usually within 30 minutes, with a duration that can last from 4 to 12 hours depending on the formulation. When taken orally, absorption occurs in the gastrointestinal tract, and it is subject to first-pass metabolism. The drug is metabolized in the liver and excreted primarily in the urine.

Contra-indications

• Hypersensitivity to pilocarpine or any of its components
• Acute iritis or uveitis
• Narrow-angle glaucoma

Adverse effects

• Local irritation
• Headache
• Flushing
• Increased salivation
• Sweating
• Diarrhea
• Nausea

Interactions

• May enhance the effects of other cholinergic agents
• Anticholinergic agents may diminish the effect of pilocarpine

Precautions

• Use with caution in patients with asthma or other respiratory conditions
• Caution in patients with cardiovascular disease, as pilocarpine can cause bradycardia
• Monitor for signs of systemic absorption in patients receiving local therapy

Pregnancy

Pilocarpine should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus, as there are no adequate and well-controlled studies in pregnant women.

Breast-feeding

It is not known whether pilocarpine is excreted in human milk, caution should be exercised when administering to nursing women.

Storage

Store at room temperature, protected from light. Keep out of reach of children.

Formulations

• Ophthalmic solution
• Oral tablets