Pain- Pregabalin and Gabapentin DI

Question 1

Drug class of pregabalin and gabapentin

Answer 1

Alpha-2 delta ligands

Question 2

Indication for gabapentin

Answer 2

PHN

Question 3

Indications for pregabalin

Answer 3

PDN, PHN, fibromyalgia

Question 4

MoA of alpha-2 delta ligands

Answer 4

Binds to presynaptic neurons at the alpha-2-delta subunit of voltage-gated calcium channels

Drug binding reduces calcium influx into presynpatic terminals

Decreased calcium influx reduces excessive release of excitatory neurotransmitters (glutamate, substance P, noradrenaline)

Question 5

Pros of pregabalin and gabapentin

Answer 5

Low incidence of DIs and ADEs
Pregabalin can help with anxiety

Question 6

Cons of gabapentin

Answer 6

mild CNS depression, significant in toxicity, needs renal dosing adjustments

Question 7

Cons of pregabalin

Answer 7

Schedule V, so there’s a risk for dependency
Euphoria, mild CNS depression, significant in toxicity, renal sufficiency

Question 8

Gabapentin dosing: ≥60ml/min

Answer 8

No dosing adjustment needed

Question 9

Gabapentin dosing: >30-59ml/min

Answer 9

400-1400mg/day PO in 2 divided doses

Question 10

Gabapentin dosing: >15-29ml/min

Answer 10

200-700mg/day PO

Question 11

Gabapentin dosing: =15ml/min

Answer 11

100-300mg/day PO in 1 dose

Question 12

Gabapentin dosing: <15ml/min

Answer 12

Reduce daily dosing in proportion to the CrCl

Question 13

Gabapentin and pregabalin can be used in what population?

Answer 13

Elderly

Question 14

Gabapentin formulations available

Answer 14

PO capsule, tablet, solution
ER tablet (Grailse)
ER tablet (Horizant- gabapentin encarbil)