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Phenobarbital

Phenobarbital Dosage

Robert Chad Hakim, PharmD, BCCCPDaisy Chau, PharmD
Reviewed by Robert Chad Hakim, PharmD, BCCCP, Daisy Chau, PharmD
Last reviewed on September 4, 2026

The average cost for 60 tablets of 64.8mg of Phenobarbital is $17.98 with a free GoodRx coupon.

tabletTablet

Dosage

Quantity

Price as low as

Price per unit

16.2mg

60 tablets

$13.90

$0.23

32.4mg

60 tablets

$17.64

$0.29

64.8mg

60 tablets

$17.98

$0.30

97.2mg

60 tablets

$21.76

$0.36

60mg

60 tablets

$10.24

$0.17

100mg

60 tablets

$12.79

$0.21

15mg

60 tablets

$14.18

$0.24

30mg

60 tablets

$14.97

$0.25

ml of elixirMl of elixir

Dosage

Quantity

Price as low as

Price per unit

20mg/5ml

120 ml

$13.04

$0.11

Typical dosage for Phenobarbital

Your dose is based on your age, weight, condition, response to treatment, and sometimes the level of phenobarbital in your blood.

Seizures

  • Adults: The typical dose is 60 mg to 200 mg by mouth per day.
  • Children: The typical dose is 3 mg/kg to 6 mg/kg by mouth per day.

Sedation

  • Adults:
    • *Daytime sedation: The typical dose is 30 mg to 120 mg by mouth per day, split up into 2 or 3 doses.
    • Sedation at bedtime: The typical dose is 100 mg to 200 mg by mouth.

Your dose might differ if you’re an older adult, are in poor health, or have kidney or liver problems.

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