There was no clear evidence of beneficial effects of pregabalin in established acute postoperative pain. No studies evaluated pregabalin in chronic nociceptive pain, like arthritis.
Pregabalin at doses of 300 mg, 450 mg, and 600 mg daily was effective in patients with postherpetic neuralgia, painful diabetic neuropathy, central neuropathic pain, and fibromyalgia (19 studies, 7003 participants).
Pregabalin at 150 mg daily was generally ineffective.
Efficacy was demonstrated for dichotomous outcomes equating to moderate or substantial pain relief, alongside lower rates for lack of efficacy discontinuations with increasing dose.
The best (lowest) NNT for each condition for at least 50% pain relief over baseline (substantial benefit) for 600 mg pregabalin daily compared with placebo were
- 3.9 (95% confidence interval 3.1 to 5.1) for postherpetic neuralgia,
- 5.0 (4.0 to 6.6) for painful diabetic neuropathy,
- 5.6 (3.5 to 14) for central neuropathic pain, and
- 11 (7.1 to 21) for fibromyalgia.
With 600 mg pregabalin daily
- somnolence typically occurred in 15% to 25% and
- dizziness occurred in 27% to 46%
- Treatment was discontinued due to adverse events in 18 to 28%.
The proportion of participants reporting at least one adverse event was not affected by dose, nor was the number with a serious adverse event, which was not more than with placebo.
Higher rates of substantial benefit were found in postherpetic neuralgia and painful diabetic neuropathy than in central neuropathic pain and fibromyalgia.
For moderate and substantial benefit on any outcome NNTs for the former were generally six and below for 300 mg and 600 mg daily; for fibromyalgia NNTs were much higher, and generally seven and above.
Pregabalin has proven efficacy in neuropathic pain conditions and fibromyalgia.
A minority of patients will have substantial benefit with pregabalin, and more will have moderate benefit.
Many will have no or trivial benefit, or will discontinue because of adverse events.
Individualisation of treatment is needed to maximize pain relief and minimize adverse events.
There is no evidence to support the use of pregabalin in acute pain scenarios.
Several classes of medications such as
- tricyclic antidepressants,
- narcotic analgesics, and
- α2-δ ligands, such as pregabalin,
have been reported to be efficacious in the treatment of painful diabetic peripheral neuropathy (DPN) and postherpetic neuralgia (PHN) in whites.
However, no large double-blind, placebo-controlled trials have been reported that evaluated the efficacy of pregabalin for the treatment of neuropathic pain in a Chinese population in China.
Pregabalin and placebo treatment groups were well-matched in terms of demographic and patient characteristics.
On the primary outcome, end point change in mean DPRS score, treatment with pregabalin (N = 206) resulted in significant improvement compared with results with placebo (N = 102), with a least squares mean difference score of -0.6 (P = 0.005).
With regard to responder rates, 64% and 52% of patients treated with pregabalin and placebo, respectively, reported ≥30% improvement in DPRS scores (P = 0.04).
Treatment with pregabalin also resulted in significant efficacy compared with that of placebo on secondary measures, including SF-MPQ VAS score (P = 0.012), SF-MPQ present pain intensity index score (P = 0.003), sleep interference score (P = 0.023), and PGIC and CGIC scores (P = 0.004 and P = 0.001, respectively).
Adverse events were observed in 50.0% of pregabalin patients and 40.2% of placebo patients (P = 0.105), with the most common adverse event being dizziness (11.2%).
Study results suggest that relative to placebo, pregabalin in daily doses of 150 to 600 mg/d was effective and well tolerated in Chinese patients diagnosed with moderate-to-severe DPN or PHN, indicated through improved pain scores and PGIC scores.
This is a very narrow and focused result, which may not apply to American patients. The previous study conducted in the US shows 150 mg/d of pregabalin to be ineffective.
I’m sure the biopsychosocial aspects of pain are very different in the Asian culture, as is the amount of discomfort great enough to prompt a complaint, like dizziness or fatigue. Therefore, I suspect the study results may not be valid for Americans.