Pilocarpine

Registered South African indications:

• Open-angle glaucoma
• Antagonism of the effects of short-acting mydriatics

Contraindications 

• Hypersensitivity to the active ingredient or any of its excipients
• Acute iritis
• Anterior uveitis
• Some forms of secondary glaucoma
• Concomitant use of soft contact lenses

Cautions 

• Pregnancy
• Breastfeeding
• Renal impairment
• Hepatic impairment
• Treatment of acute closed-angle glaucoma where higher doses are administered
• Bronchial asthma
• Peptic ulceration
• Urinary tract obstruction
• Parkinson's disease
• Acute heart failure
• Hypertension
• Pre-existing retinal disease
• Patients susceptible to retinal detachment
• May impair ability to drive and operate machinery

Forms avail. in SA and covered in this monograph: opd, gel

Open-angle glaucoma

• Ophthalmic (opd): 1-2 drops into affected eye(s), 6hrly
• Ophthalmic (gel): 5-15mm ribbon into conjunctival sac, dly at night

The strength of the preparation and the frequency of use are determined by the severity of the condition and the response to treatment

Prior to surgery for acute attacks of closed-angle glaucoma

• Ophthalmic (opd): 1 drop into affected eye(s), every 5min until miosis is obtained or as clinically required

Miosis
- To counteract effects of cycloplegic or mydriatic eye drops

• Ophthalmic (opd): 1 drop into eye(s); Repeat after 5min until the effect is counteracted or as clinically required

- To antagonise the effects of short-acting mydriatics on the eye (and alternated with mydriatics to break adhesions between the iris and the lens)

• Ophthalmic (opd): 2 drops into affected eye(s), 6-8hrly

Paed. forms avail. in SA and covered in this monograph: opd

• Consult specialist for dosages and regimens

Based on the infrequency of reports of adverse events in children, and the extensive experience of use of pilocarpine in childhood glaucoma, concentrations of up to 2% may be safely used in children, but no recommendation on a posology can be made

Treatment should be started with the lowest available dose and concentration in patients under 18 years of age. Depending on clinical response and tolerability, the dose may be increased up to the maximum recommended adult dosage of the 2% pilocarpine. Directly after administration of any dose, the lacrimal punctum should be occluded for one minute with a finger to limit systemic exposure

Pregnancy

• Caution; not recommended
• Safety of pilocarpine for use during pregnancy has not been established. Ophthalmic pilocarpine may be systemically absorbed and mothers using the drug may give birth to infants with signs mimicking neonatal meningitis such as restlessness, convulsions, diaphoresis and hypothermia. Pilocarpine should therefore only be used during pregnancy when essential

Breastfeeding

• Caution
• Safety of pilocarpine for use during breastfeeding has not been established and it should therefore only be used when clearly indicated. It is not known whether pilocarpine is excreted in breast milk. The possibility of systemic absorption however, should be borne in mind

Renal Impairment

• Caution; no information available

Hepatic Impairment

• Caution; no information available

Elderly

• No dose adjustment recommended

Porphyria Information

• Probably not porphyrinogenic (PNP)

Drugs in Sport

• Permitted - No warnings

Central Nervous System Disorders 

• Headache
• Browache
• Tremor    

Cardiovascular Disorders 

• Changes in cardiac rhythm
• Changes in blood pressure

Respiratory Disorders

• Bronchial spasm
• Pulmonary oedema

Gastrointestinal Disorders 

• Nausea and vomiting
• Diarrhoea
• Increased salivation

Skin and Subcutaneous Tissue Disorders

• Sweating

Sensory Disorders 

• Decreased visual acuity in poor illumination (frequently experienced by older individuals and in patients with lens opacity)
• Itching of eyes
• Discomfort and burning of eyes
• Sensitisation of the eyelids
• Conjunctival vascular congestion
• Superficial keratitis
• Ciliary spasm
• Blurred vision
• Induced myopia
• Transient myopia
• Lens changes (chronic use)
• Increased pupillary block
• Vitreous haemorrhages
• Retinal detachments
• Lacrimation

• Anticholinesterases
• Anticholinergics
• Monoamine oxidase inhibitors
• Phenothiazines
• Antihistamines
• Tricyclic antidepressants
• Adrenergic blockers
• Alcohol

• Fundus examination

Specific cases may require

• Visual fields
• Intraocular pressure

Pilocarpine is a direct-acting cholinergic agonist. It acts primarily at muscarinic receptor sites both peripherally and centrally, affecting smooth muscle, the cardiovascular system and exocrine glands. The precise mechanism by which pilocarpine reduces intraocular pressure has not been established, though it is believed to involve direct stimulation of the longitudinal muscle of the ciliary body, which in turn affects the scleral spur, widening the trabecular spaces and allowing for increased aqueous flow. Pilocarpine may also decrease aqueous formation with long term administration. Due to its activity at the muscarinic receptor sites of the ciliary muscles and iris sphincter, pilocarpine causes varying degrees of accommodation spasm and pupillary constriction.

Eye drops (per ml) 10mg

• Isopto Carpine 1% (Novartis) originator

Eye drops (per 0.5ml) 10mg

• Isopto Carpine 2% (Novartis) originator

Eye drops (per ml) 40mg

• Isopto Carpine 4% (Alcon) originator

Ophthalmic gel drop (per g) 40mg

• Pilogel 4% (Alcon) originator