Primidone

DRUG INFORMATION

  ADULT
    - Usual Dosage Patients 8 years of age and older who have received no previous
      treatment may be started on primidone tablets according to the following regimen
      using either 50 mg or scored 250 mg primidone tablets: Days 1 to 3: 100 to 125 mg
      at bedtime.
      Source: US FDA label for primidone (Primidone), section 'dosage and
      administration', retrieved 2026-08-29
    - Days 7 to 9: 100 to 125 mg three times a day.
      Source: US FDA label for primidone (Primidone), section 'dosage and
      administration', retrieved 2026-08-29
    - Day 10 to maintenance: 250 mg three times a day.
      Source: US FDA label for primidone (Primidone), section 'dosage and
      administration', retrieved 2026-08-29

  CHILD
    - Usual Dosage Patients 8 years of age and older who have received no previous
      treatment may be started on primidone tablets according to the following regimen
      using either 50 mg or scored 250 mg primidone tablets: Days 1 to 3: 100 to 125 mg
      at bedtime. Days 4 to 6: 100 to 125 mg twice a day. Days 7 to 9: 100 to 125 mg
      three times a day. Day 10 to maintenance: 250 mg three times a day.
      Source: US FDA label for primidone (Primidone), section 'dosage and
      administration', retrieved 2026-08-29
    - Usual Dosage Patients 8 years of age and older who have received no previous
      treatment may be started on primidone tablets according to the following regimen
      using either 50 mg or scored 250 mg primidone tablets: Days 1 to 3: 100 to 125 mg
      at bedtime.
      Source: US FDA label for primidone (Primidone), section 'dosage and
      administration', retrieved 2026-08-29
    - For most adults and children 8 years of age and over, the usual maintenance dosage
      is three to four 250 mg primidone tablets in divided doses (250 mg three times a
      day or four times a day).
      Source: US FDA label for primidone (Primidone), section 'dosage and
      administration', retrieved 2026-08-29

  RENAL IMPAIRMENT
    - No kidney-impairment dose in this label. Not a statement that none is needed.
      Source: Read and found silent: the US FDA label for primidone (Primidone),
      retrieved 2026-08-29

  HEPATIC IMPAIRMENT
    - No liver-impairment dose in this label. Not a statement that none is needed.
      Source: Read and found silent: the US FDA label for primidone (Primidone),
      retrieved 2026-08-29

  PREGNANCY
    - To provide information regarding the effects of in utero exposure to primidone
      tablets, physicians are advised to recommend that pregnant patients taking
      primidone tablets enroll in the North American Antiepileptic Drug (NAAED)
      Pregnancy Registry.
      Source: US FDA label for primidone (Primidone), section 'pregnancy', retrieved
      2026-08-29
    - This can be done by calling the toll-free number 1-888-233-2334, and must be done
      by patients themselves.
      Source: US FDA label for primidone (Primidone), section 'pregnancy', retrieved
      2026-08-29
    - Information on the registry can also be found at the website
      http://www.aedpregnancyregistry.org/.
      Source: US FDA label for primidone (Primidone), section 'pregnancy', retrieved
      2026-08-29

  BREASTFEEDING
    - There is evidence in mothers treated with primidone that the drug appears in
      breast milk in substantial quantities.
      Source: US FDA label for primidone (Primidone), section 'nursing mothers',
      retrieved 2026-08-29
    - Since tests for the presence of primidone in biological fluids are too complex to
      be carried out in the average clinical laboratory, it is suggested that the
      presence of undue somnolence and drowsiness in nursing newborns of primidone-
      treated mothers be taken as an indication that nursing should be discontinued.
      Source: US FDA label for primidone (Primidone), section 'nursing mothers',
      retrieved 2026-08-29