Pilocarpine is a direct-acting cholinergic parasympathomimetic alkaloid, primarily used as a muscarinic receptor agonist. In the 5mg oral tablet formulation, it is indicated for the treatment of xerostomia (dry mouth) caused by salivary gland hypofunction resulting from radiotherapy for head and neck cancer or in Sjögren's syndrome. It stimulates exocrine gland secretion, including salivary and sweat glands.
Adult: For xerostomia: Initially, 5mg orally three times a day. May be titrated based on response and tolerability to a maximum of 10mg three times a day. Typical maintenance dose is 5mg TID.
Note: Take orally with or without food. Taking with food may reduce gastrointestinal side effects but can delay onset. Swallow tablet whole with a full glass of water. Do not crush or chew. Dose should be taken at regular intervals, typically with meals. Adequate fluid intake is recommended.
Pilocarpine is a direct-acting cholinergic agonist with predominant muscarinic (M3) receptor activity. It binds to and activates muscarinic acetylcholine receptors on the effector cells of exocrine glands (salivary, sweat, lacrimal, pancreatic) and smooth muscles (bronchial, gastrointestinal, urinary bladder, biliary). This activation mimics the action of acetylcholine, leading to increased secretion and smooth muscle contraction.
Pregnancy: Category C: Animal reproduction studies have shown adverse effects. There are no adequate and well-controlled studies in pregnant women. Use only if the potential benefit justifies the potential risk to the fetus. Can stimulate uterine smooth muscle.
Driving: May cause blurred vision, dizziness, and impaired accommodation. Patients should be cautioned about driving or operating machinery until they know how the drug affects them.
| Beta-adrenergic Blockers (e.g., Propranolol, Atenolol) | Additive risk of conduction disturbances (heart block, bradycardia). | Major |
| Other Cholinergic Agonists (e.g., Bethanechol, Cevimeline) | Additive cholinergic effects and toxicity. | Major |
| Anticholinergic Drugs (e.g., Atropine, Oxybutynin, TCAs, Antihistamines) | Mutual antagonism; pilocarpine effect reduced. | Moderate |
| Parasympathomimetics (Cholinesterase Inhibitors like Donepezil, Rivastigmine) | Additive cholinergic effects and toxicity. | Moderate |
| Pilocarpine Ophthalmic Solution | Additive systemic cholinergic effects. | Moderate |