Oral pilocarpine for xerostomia (dry mouth)

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  • 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.
    • The liquid is generally swallowed.
  • Because response may be delayed, a trial of up to 3 months may be reasonable if treatment is tolerated.
  • If response to 5 mg is inadequate, some patients may benefit from a higher dose if tolerated, up to a maximum of 30 mg/day.
  • 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
    • There are no specific stability data for this formulation. Based on generic guidance in the United States Pharmacopoeia (USP), Australian Pharmaceutical Formulary (APF), and Pharmaceutical Society of New Zealand (PSNZ) Pharmacy Practice Handbook, a reasonable approach is to store in the fridge or at room temperature with a 1-month expiry. If no preservative is used, a 14-day expiry in the fridge should be assigned.
  • 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. 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

  2. SmPC Salagen (pilocarpine) tablets [Internet]. Norgine Limited. Available from: https://www.medicines.org.uk/emc/product/1370/smpc

  3. PHARMAC. PHARMAC Te Pātaka Whaioranga [Internet]. [cited 2026 May 18]. Available from: https://www.pharmac.govt.nz/

  4. pilocarpine oral liquid – New Zealand Formulary [Internet]. [cited 2026 May 18]. Available from: https://nzf.org.nz/nzf_9679

  5. United States Pharmacopeial Convention. General chapter <795> pharmaceutical compounding—nonsterile preparations. 2022.

  6. Australian Pharmaceutical Formulary and Handbook. 26th ed. Canberra (AU): Pharmaceutical Society of Australia; 2024.

  7. Pharmacy Practice Handbook. Wellington (NZ): Pharmaceutical Society of New Zealand Inc.; 2026.