Oral pilocarpine for xerostomia (dry mouth)

  • Usual dose: 5 mg up to four times daily.
    • Best taken about 30 minutes before meals to improve salivary flow for eating.
    • To reduce the chance of adverse effects, treatment may be started more gradually, such as 5 mg once daily for the first week, then increased as tolerated.
    • Common adverse effects include sweating, flushing, increased urinary frequency, and diarrhoea.
  • Because response may be delayed, a 3-month trial is reasonable if treatment is tolerated.
  • If response to 5 mg is inadequate, some patients may benefit from an increase to 7.5 mg.
  • If full-dose treatment causes adverse effects, lower doses such as 2.5 mg three times daily or 5 mg twice daily may still be helpful.
Formulations
  • Pilocarpine tablets are available overseas, but not in Aotearoa New Zealand.
  • Pilocarpine 4% (40 mg/mL) eye drops can be used orally and are funded for this purpose.
  • The NZF references PHARMAC’s standard formula for an oral liquid:
    • Pilocarpine 4% eye drops q.s.
    • Preservative q.s.
    • Water to 500 mL.
  • A 1 mg/mL oral liquid is a practical strength for a 5 mg dose.
    • Example using one 15 mL bottle of 4% eye drops (final concentration 1 mg/mL):
      • Pilocarpine 4% eye drops: 15 mL = 600 mg
      • Preservative e.g. compound hydroxybenzoate or methyl hydroxybenzoate: 6 mL
      • Water: to 600 mL
    • Based on guidance in the PSNZ Pharmacy Practice Handbook, a reasonable approach is to store in the fridge with a 1-month expiry. If no preservative is used, a 7-day expiry is appropriate.
  • Alternatively, the 4% eye drops can be applied directly to the oral cavity. Assuming about 12 drops per mL, each drop contains about 3 mg of pilocarpine.
References
  1. PHARMAC. PHARMAC Te Pātaka Whaioranga [Internet]. [cited 2026 May 18]. Available from: https://www.pharmac.govt.nz/
  2. pilocarpine oral liquid – New Zealand Formulary [Internet]. [cited 2026 May 18]. Available from: https://nzf.org.nz/nzf_9679
  3. Pharmacy Practice Handbook. Wellington (NZ): Pharmaceutical Society of New Zealand Inc.; 2026.
  4. Baer AN, Sankar V. Treatment of dry mouth and other non-ocular sicca symptoms in Sjögren’s disease [Internet]. [cited 2026 May 18]. Available from: https://www.uptodate.com/contents/treatment-of-dry-mouth-and-other-non-ocular-sicca-symptoms-in-sjogrens-disease?search=pilocarpine&source=search_result&selectedTitle=2~34&usage_type=default&display_rank=1&searchCorrelationId=0c60a3c8-9fa2-4c46-a8aa-49e73747a0c2&searchCorrelationTerm=pilocarpine