
Pregabalin Information Sheet
- Pregabalin comes as capsules: 25 mg, 75 mg, 150 mg, 300 mg (other sizes are approved in NZ but not funded).
- Cost is 10 to 26 cents per day versus 12 to 48 cents for gabapentin.
- Special Authority is not required for pregabalin and is no longer in place for gabapentin formulations.
- Significant abuse of pregabalin has been reported in the US, UK, and Europe.
Indications
- Neuropathic pain – evidence of efficacy is poor and no better than other agents. Have a low threshold for ceasing if ADRs occur.
- Shown to be ineffective in cancer-related bone pain (as has gabapentin).
- Focal seizures – dose as below but 1st increase after 7 days.
- Generalised anxiety (unapproved)
Dosing recommendations
Doses in normal renal function range from 150 to 600 mg per day. As for most medicines, consider lowest doses in frail or elderly patients.
- Neuropathic pain – initially 75 mg PO BD (some centres start on 25 mg BD) increasing after 3 to 7 days to 150 mg PO BD and again after 7 days to 300 mg PO BD if necessary.
- Generalised anxiety – dose 150 mg/day in 2 to 3 doses increasing by 150 mg/day at 7 day intervals to a maximum of 600 mg/day in 2 to 3 divided doses.
Gabapentin:
- Do not use in combination with gabapentin.
- If switching from gabapentin to pregabalin the conversion ratio is unclear, but consider using a 6:1 gabapentin:pregabalin or retitrate as above.
Clearance and half-life
Pregabalin is cleared renally (like gabapentin) with 90% excreted unchanged so dose adjustments are required for renal function:
CrCL
|
initial dose/day
|
max dose/day
|
no. of doses/day
|
> 60 mL/min
|
150 mg/day
|
600 mg/day
|
in 2 doses
|
30–60 mL/min
|
75 mg/day
|
300 mg/day
|
in 1 or 2 doses
|
15–30 mL/min
|
25–50 mg/day
|
150 mg/day
|
in 1 or 2 doses
|
<15 mL/min
|
25 mg/day
|
75 mg/day
|
in 1 dose
|
after haemodialysis
|
(single dose)
|
initially 25 mg/day
|
max. 100 mg
|
- On ceasing it is recommended to withdraw slowly over 7 days (may not be necessary at very low doses).
- Absorption (90%) is better than gabapentin's (25–70%), making for more predictable effects and perhaps useful in gut dysfunction.
- Time to maximum concentrations post dose is 1 hour.
- Half-life is 6 to 12 hours, steady state in 2 to 4 days.
- Mechanism of action is similar to gabapentin and may be through effects on calcium channels in CNS and reduction of glutamate, noradrenaline, and substance P release.
Adverse drug reactions (ADR)
1 in 3 patients will be harmed by pregabalin (but this may be less than gabapentin).
It has many ADRs, including:
- somnolence
- cognitive impairment
- dry mouth
- constipation
- dizziness
- suicidal ideation
- QTc prolongation
Topic Code: 526948