Do Surgical Patients Benefit from Perioperative Gabapentin/Pregabalin? A Systematic Review of Efficacy and Safety

Pregabalin and dexamethasone in combination with paracetamol for postoperative pain control after abdominal hysterectomy. A randomized clinical trial

BACKGROUND

Multimodal analgesia may be important for optimal postoperative pain treatment and facilitation of early mobilization and recovery. We investigated the analgesic effect of pregabalin and dexamethasone in combination with paracetamol after abdominal hysterectomy.

METHODS

One hundred and sixteen patients were randomly assigned to either group A (paracetamol+placebo x 2), group B (paracetamol+pregabalin+placebo) or group C (paracetamol+pregabalin+dexamethasone). According to randomization and preoperatively, patients received paracetamol 1000 mg, pregabalin 300 mg, dexamethasone 8 mg or placebo. General anaesthesia was performed. Postoperative pain treatment was paracetamol 1000 mg x 4 and patient-controlled intravenous morphine, 2.5 mg bolus. Nausea was treated with ondansetron. Morphine consumption, pain score (visual analogue scale) at rest and during mobilization, nausea, sedation, dizziness, number of vomits and consumption of ondansetron were recorded 2, 4 and 24 h after the operation. P<0.05 was considered statistically significant.

RESULTS

The 24-h morphine consumption and pain score, both at rest and during mobilization, were not significantly different between treatment groups. The mean nausea score (P=0.002) was reduced in group C vs. A. The number of vomits was significantly reduced in both group B (P=0.041) and C (P=0.001) vs. A. Consumption of ondansetron was reduced in group C vs. A and B (P<0.001). Other side effects were not different between groups.

CONCLUSION

Combinations of paracetamol and pregabalin, or paracetamol, pregabalin and dexamethasone did not reduce morphine consumption and pain score compared with paracetamol alone for patients undergoing abdominal hysterectomy. Dexamethasone reduced nausea, vomiting and use of ondansetron.

Adjunctive analgesic therapy in veterinary medicine

Adjunctive analgesic therapies are interventions for pain that involve agents or techniques other than the traditional analgesics (opioids, nonsteroidal anti-inflammatory drugs, and local anesthetics). Adjunctive therapies may be pharmacologic or nonpharmacologic in nature. The focus of this article is on pharmacologic interventions with potential utility as adjunctive analgesics in veterinary medicine. Pharmacology of selected agents, including medetomidine, ketamine, amantadine, gabapentin, systemic lidocaine, and pamidronate, is discussed in addition to evidence for their safety and efficacy and guidelines for their use in veterinary patients.

[New substances and applications for postoperative pain therapy]

The onset of postoperative pain is the result of various pathophysiological mechanisms and depends on the type of surgery performed. Therefore, any adequate postoperative pain treatment requires multimodal and procedure-specific analgesia. In addition to reducing perioperative complications and improving patient comfort, optimal postoperative pain management also represents an important quality characteristic which can influence the patient in their choice of hospital. In the past 1-2 years, known groups of substances have been rediscovered for postoperative pain therapy (e.g., Gabapentin and Pregabalin, i.v. Lidocaine, Ketamine or glucocorticoids), while new substances (coxibe, oral oxycodone+naloxone) and applications have been developed. The present overview article discusses the advantages and disadvantages of these substances and analgesic methods, as well as their specific areas of application.

[Drugs for postoperative analgesia: routine and new aspects: Part 2: opioids, ketamine and gabapentinoids]

In part 1 of this review, perioperative aspects of the use of non-opioids (acetaminophene, dipyrone, traditional NSAR, coxibs) were discussed. In part 2 the perioperative aspects of opioids (weak opioids: tramadol, tilidine with naloxone, strong opioids: morphine, piritramide, oxycodone, hydromorphone, fentanyl, methadone, buprenorphine) and coanalgesics (gabapentinoids; ketamine) will now be presented. The main aim of the review is to describe the use, risks and cost of some substances to facilitate the differential indication. New aspects concerning the use of gabapentinoids and ketamine are discussed.

Drug treatment of delirium: past, present and future

OBJECTIVE

The aim of this review was to summarize and critically evaluate the current literature regarding the safety and efficacy of drug therapy in delirium. We also identified recent research developments and highlighted some ongoing clinical trials to explore future directions in drug treatment and prevention of delirium.

METHODS

We conducted a literature search of Medline, Embase, PsychInfo, and Cochrane Review databases, which included both prospective and retrospective clinical trials and case studies on delirium and drug therapy in adult patients up to March 2008. Abstracts from recent topical conferences were also reviewed. Ongoing delirium drug studies were identified via the WHO International Clinical Trials Registry Platform Search Portal, accessed March 12, 2008.

RESULTS

The evidence base for effective drug treatment of delirium is restricted by limitations in many of the studies conducted to date. However, there has been an increase in the quantity and quality of delirium drug studies in recent years; preliminary reports and ongoing studies add to this trend. Although efficacy rates between typical and atypical antipsychotic agents are similar, the latter are associated with fewer extrapyramidal side effects. Prophylactic interventions with antipsychotic and cholinesterase inhibitors in high-risk patients provide an opportunity to improve postoperative patient care. Alternative techniques and medication opportunities could be explored in attempts to minimize drug induced delirium potential.

CONCLUSIONS

Appropriate drug therapy should be considered part of systematic approaches to delirium treatment and prevention. There is a need for well-designed randomized, double-blind placebo-controlled trials investigating the drug management of various aspects of delirium, including delineating treatment by delirium subtype, dose ranging studies, and optimal duration of therapy.

Effect of oral gabapentin on the intraocular pressure and haemodynamic responses induced by tracheal intubation

BACKGROUND

Laryngoscopy and tracheal intubation may cause undesirable increases in blood pressure, heart rate (HR) and intraocular pressure (IOP). Gabapentin has been used effectively to attenuate the pressor response to laryngoscopy and tracheal intubation. We investigated whether the pre-treatment with gabapentin attenuates the IOP in addition to a haemodynamic response to tracheal intubation.

METHODS

Sixty ASA I-II patients were randomly allocated into two groups who received either gabapentin (800 mg) or placebo 2 h before surgery. IOP, mean arterial pressure (MAP) and HR were measured before and after the induction of anaesthesia as well as at 0, 1, 3, 5, 10 and 15 min following intubation.

RESULTS

IOP and MAP increased from baseline immediately after intubation in the placebo group (P=0.001 and 0.002, respectively). When compared with the placebo group, IOP values of the gabapentin group were significantly lower for the first 15 min after tracheal intubation (P=0.002 at 0 min, P=0.006 at 1 min, P<0.001 at 3 min, P<0.001 at 5 min, P<0.001 at 10 min and P=0.003 at 15 min) while MAP was lower in the first 10 min (P=0.001 at 0 min, P=0.002 at 1 min, P<0.001 at 3 min, P<0.001 at 5 min and P=0.028 at 10 min). These results showed that gabapentin effectively suppresses the increase in IOP secondary to endotracheal intubation and attenuates the increases in MAP.

CONCLUSION

It is suggested that gabapentin is a useful adjuvant in order to prevent an increase in the IOP in response to laryngoscopy and tracheal intubation.

Analgesia best practice after cardiac surgery

Sources of pain after cardiac surgery include sternotomy, rib retraction, conduit harvest, and drain tubes sites. An analgesic regimen should consider individual patient characteristics, including age, preoperative history of pain and response to analgesics, comorbidities, and psychologic state. Intraoperative and postoperatively administered opioids remain the mainstay of therapy, but adjunctive analgesics such as paracetamol, nonsteroidal anti-inflammatory drugs and tramadol, and regional techniques, can reduce opioid consumption and opioid-induced respiratory depression. This may facilitate earlier tracheal extubation, mobilization, and recovery.

Pregabalin in the management of central neuropathic pain

Central neuropathic pain is a painful condition, often severe, that occurs in a person who is already affected by an injury or disease of the brain or spinal cord. This dual insult is especially threatening to the quality of life of a person and their ability to perform even the most basic of tasks. Despite this high level of suffering there are relatively few trials investigating the management of central neuropathic pain. However, two randomised placebo-controlled studies have recently emerged demonstrating efficacy of pregabalin in reducing central neuropathic pain due to spinal cord injury and central poststroke pain. Pregabalin, an anticonvulsant, has been shown to be efficacious in the management of peripheral neuropathic pain of various causes and now may have a role to play in central neuropathic pain.

Gabapentin and pregabalin for chronic neuropathic and early postsurgical pain: current evidence and future directions

PURPOSE OF REVIEW

Gabapentin and pregabalin bind to the alpha-2-delta calcium channel subunit and represent a novel analgesic drug class. The evidence base supporting their use for chronic neuropathic and early postsurgical pain is reviewed.

RECENT FINDINGS

Multiple, large, high-quality trials have demonstrated the safety and efficacy of gabapentin and pregabalin in neuropathic pain. Treatment-related improvement of pain and sleep positively impact upon quality of life. Sedation, dizziness and ataxia are important and relatively common adverse effects, however. Accumulating evidence indicates that gabapentin, and possibly pregabalin, also exert important effects following surgery. Multiple high-quality trials have demonstrated analgesic and opioid-sparing efficacy with gabapentin following various surgical procedures. Gabapentin and pregabalin reduce movement-evoked pain and this can lead to enhanced functional postoperative recovery. Postoperative opioid sparing is of questionable relevance since few trials have shown reduced opioid-related adverse effects. Sedation, dizziness and ataxia have been reported in only a few trials. Future larger-scale perioperative trials focused on safety assessment are needed, however.

SUMMARY

Gabapentin and pregabalin are efficacious treatments for neuropathic and postsurgical pain. Future research addressing several specific questions would serve to better delineate their optimal roles in treating these and other pain conditions.