Factors predicting adverse events associated with pregabalin administered for neuropathic pain relief

Pregabalin induced balance disorder, asthenia, edema, and constipation in an elderly adult: A case report

BACKGROUND

Pregabalin is widely used to treat neuropathic pain associated with postherpetic neuralgia. To our knowledge, this is the first report on simultaneously occurring dose-related adverse drug reactions (ADRs) of balance disorder, asthenia, peripheral edema, and constipation in an elderly patient after pregabalin.

CASE SUMMARY

A 76-year-old female with a history of postherpetic neuralgia was prescribed pregabalin (300 mg daily). After taking pregabalin for 7 d, the patient developed balance disorder, weakness, peripheral pitting edema (2+), and constipation. On days 8-14, the pregabalin dose was reduced to 150 mg/d based on creatinine clearance. The patient’s peripheral edema improved significantly with the disappearance of all other adverse symptoms. On day 15, the pregabalin dose was increased to 225 mg/d to relieve pain. Unfortunately, the symptoms mentioned earlier gradually reappeared after 1 wk of pregabalin treatment. However, the complaints were not as severe as when taking 300 mg/d pregabalin. The patient consulted her pharmacist by telephone and was advised to reduce the dose of pregabalin to 150 mg/d and add acetaminophen (0.5 g, q6h) to relieve pain. The patient’s ADRs gradually improved over the following week.

CONCLUSION

Older patients should be prescribed a lower initial dose of pregabalin. The dose should be titrated to the maximum tolerable dose to avoid dose-limiting ADR. Dose reduction and the addition of acetaminophen may help limit ADR and improve pain control.

Combination Therapy for Neuropathic Pain: A Review of Recent Evidence

Pharmacological treatment is not very effective for neuropathic pain (NP). A progressive decrease in the estimated effect of NP drugs has been reported, giving rise to an increase in the use of the multimodal analgesic approach. We performed a new independent review to assess whether more and better-quality evidence has become available since the last systematic review. We evaluated the efficacy, tolerability, and safety of double-blinded randomized controlled trials involving only adult participants and comparing combination therapy (CT: ≥2 drugs) with a placebo and/or at least one other comparator with an NP indication. The primary outcome assessed was the proportion of participants reporting ≥50% pain reductions from baseline. The secondary outcome assessed was the proportion of drop-outs due to treatment-emergent adverse events. After removing duplicates, 2323 citations were screened, with 164 articles assessed for eligibility, from which 16 were included for qualitative analysis. From the latter, only five lasted for at least 12 weeks and only six complied with the required data for complete analysis. CT has been adopted for years without robust evidence. Efforts have been made to achieve better-quality evidence, but the quality has not improved over the years. In this regard, guidelines for NP should attempt to make recommendations about CT research, prioritizing which combinations to analyze.

Pregabalin-associated stuttering and frequent blepharospasm: case report and review

Herpes zoster is an acute, painful, herpes skin disease caused by varicella-zoster virus, which may cause viral meningitis. Pregabalin has been shown to be efficacious in the treatment of pain in patients with herpes zoster. However, it has the side effects of neurotoxicity. We describe a 68-year-old female patient with herpes zoster, and she was treated with pregabalin. The patient presented with stuttering and frequent blepharospasm after 3 days of pregabalin treatment. Pregabalin was discontinued, the symptoms of stuttering and frequent blepharospasm completely resolved without any special treatment after one week. In this case, the etiology of stuttering and frequent blepharospasm may be related to pregabalin. Clinicians should be alert to the rare symptoms associated with the use of pregabalin.

Graphical abstract

Comparison of the use of opioids only and pregabalin add-on for the treatment of neuropathic pain in cervical myelopathy patients: a pilot trial

Among patients with cervical myelopathy who were diagnosed with neuropathic pain (NP) by the LANSS test, the study participants were randomly assigned to one of the two study groups. The participants in one study group received opioids only, while those in the other group received opioids and pregabalin. Thirty-nine patients were analyzed in the study (20 patients in the opioid-only group and 19 in the pregabalin add-on group). The LANSS, neck pain, and arm pain scores in the pregabalin add-on group improved significantly compared with those in the opioid-only group after the first 4 weeks (p = 0.005, 0.001 and 0.035, respectively), but there was no significant difference between the two groups during the next 4 weeks (p = 0.615, 0.377 and 0.716, respectively). There was no significant difference in the neck disability index and EuroQol-5Dimension scores after four weeks and eight weeks of follow-up. Adverse events were reported by four patients (20.0%) in the opioid-only group and five patients (26.3%) in the pregabalin add-on group (p = 0.716). However, over time, the occurrence of side effects and dropouts increased in the pregabalin add-on group. This exploratory pilot study suggests that pregabalin add-on treatment is more efficient than the use of opioids alone at the beginning of NP treatment in cervical myelopathy patients. However, prescribing pregabalin add-on treatment for more than four weeks should be done cautiously.

Evaluation of the Efficacy of Prolonged Pregabalin Administration Before and After Surgery in Patients Undergoing Arthroscopic Anterior Cruciate Ligament Repair: A Prospective, Randomized, Double-blind Study

CONTEXT AND OBJECTIVE

Reconstruction of the knee ligament causes postoperative pain and delayed rehabilitation.

OBJECTIVE

The primary objective of this study was to evaluate the effect of a prolonged preoperative and postoperative pregabalin use for arthroscopic anterior cruciate ligament repair.

MATERIALS AND METHODS

Group 1 (N=25) patients received pregabalin 75 mg/d, and group 2 (N=25) received placebo, 7 days before and 7 days after surgery. Spinal anesthesia was performed using 0.5% hyperbaric bupivacaine (15 mg). The following were evaluated: pain intensity immediately after the surgery, and 12 hours, 24 hours, 1 week, 2 weeks, 1 month, and 2 months after the surgery using a Numerical Rating Scale; dose of postoperative supplementary analgesic for 2 months; time to first analgesic requirement; and side effects during 2 months. For supplementation, the participants received 1 g dipyrone; if there was no pain control, 100 mg ketoprofen was administered; if there was no effect, 100 mg tramadol was administered; and if there was no pain control, 5 mg intravenous morphine was administered until pain control.

RESULTS

There was no difference between the groups with regard to pain intensity (P=0.077). In the pregabalin group, morphine consumption was lower at 12 hours (P=0.039) and 24 hours (P=0.044) after surgery, and the consumption of tramadol and ketoprofen was lower 24 hours after surgery. There was no significant difference in the incidence of nausea and vomiting. Dizziness was higher in the pregabalin group (group 1=12 patients; group 2=3 patients; P=0.005).

DISCUSSION

A prolonged preoperative and postoperative pregabalin prescription for anterior cruciate ligament repair decreased the need for supplementary analgesics during the first 24 postoperative hours but increased dizziness.

Alleviation of pain in painful diabetic neuropathy

INTRODUCTION

Painful diabetic neuropathy (PDN) is a disabling pain condition. Its pathomechanism remains unknown, but a sensitization and neuronal hyperexcitabilty have been suggested. Only symptomatic pharmacological pain management treatment is currently available.

AREAS COVERED

The origin of PDN is enigmatic, and the evidence-based therapeutic guidelines therefore consist only of antidepressants and antiepileptics as first-line recommended drugs. This article relates to a MEDLINE/PubMed systematic search (2005-2015).

EXPERT OPINION

The results of the meta-analysis from the aspect of the efficacy of amitriptyline, duloxetine, venlafaxine, gabapentin and pregabalin are favorable, but the placebo response rate is relatively high in patients with neuropathic pain. For personalization of the medication of PDN patients, the optimum dosing, the genotyping of the metabolizing enzymes and optimum biomarkers are needed. As concerns the future perspectives, specific sodium channel subtype inhibitors acting on peripheral nociceptive neurons or modified T-type voltage-gated calcium channel blockers may be promising targets for pharmaceutical innovations. Another attractive strategy for the treatment is based on the effects of monoclonal antibodies against nerve growth factor, sodium channels, specific receptor and cytokines. Botulinum toxin A, capsaicin patch and spinal cord stimulation therapies are the nearest future therapeutic options for the treatment of PDN patients.

Pregabalin for decreasing pancreatic pain in chronic pancreatitis

BACKGROUND

Chronic abdominal pain is one of the major symptoms in people with chronic pancreatitis. The role of pregabalin in people with chronic pancreatic pain due to chronic pancreatitis is uncertain.

OBJECTIVES

To assess the benefits and harms of pregabalin in people with chronic abdominal pain due to chronic pancreatitis.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library 2015, issue 6, and MEDLINE, EMBASE, Science Citation Index Expanded, trials registers until June 2015. We also searched the references of included trials to identify further trials.

SELECTION CRITERIA

We considered only randomised controlled trials (RCT) performed in people with chronic pancreatic pain due to chronic pancreatitis, irrespective of language, blinding, or publication status for inclusion in the review.

DATA COLLECTION AND ANALYSIS

Two review authors independently identified trials and independently extracted data. We calculated the risk ratio (RR) or mean difference (MD) with 95% confidence intervals (CI) with RevMan 5, based on intention-to-treat analysis.

MAIN RESULTS

Only one study, funded by Pfizer, met the inclusion criteria for the review. A total of 64 participants (with chronic pain due to chronic pancreatitis) were randomly assigned to receive escalating doses of pregabalin (150 mg per day to 600 mg per day; 34 participants) or matching placebo (30 participants). Participants received pregabalin or placebo for three weeks on an outpatient basis; the outcomes were measured at the end of the treatment (i.e. three weeks from commencement of treatment). Potential participants taking concomitant analgesic medication and expected to stay on a stable regime during the trial were allowed to enter the study. This trial was at low risk of bias. The overall quality of evidence was low or moderate.Only the short-term outcomes were available in this trial. The medium and long-term outcomes, number of work days lost, and length of hospital stay due to admissions for pain control were not available. This trial found that the changes in opiate use (MD -26.00 mg; 95% CI -47.36 to -4.64; participants = 64; moderate-quality evidence), and pain score percentage changes from baseline (MD -12.00; 95% CI -21.82 to -2.18; participants = 64; moderate-quality evidence) were better in participants taking pregabalin compared to those taking placebo. This trial also found that there were more adverse events in participants taking pregabalin compared to those taking placebo (RR 1.71; 95% CI 1.20 to 2.43; participants = 64). The differences between pregabalin and placebo were imprecise for short-term health-related quality of life measured with the EORTC CLQ-30 questionnaire (MD 11.40; 95% CI -3.28 to 26.08; participants = 64; moderate-quality evidence), proportion of people with serious adverse events (RR 1.76; 95% CI 0.35 to 8.96; participants = 64; low-quality evidence), and proportion of people requiring hospital admissions (RR 0.44; 95% CI 0.04 to 4.62; participants = 64; low quality evidence).

AUTHORS' CONCLUSIONS

Based on low- to moderate-quality evidence, short-term use of pregabalin decreases short-term opiate use, and short-term pain scores, but increases the adverse events compared to placebo, in people with chronic pain due to chronic pancreatitis. The clinical implication of the decreases in short-term opiate use and short-term pain scores is not known.Future trials assessing the role of pregabalin in decreasing chronic pain in chronic pancreatitis should assess the medium- or long-term effects of pregabalin and should include outcomes such as, quality of life, treatment-related adverse events, number of work days lost, number of hospital admissions, and the length of hospital stay, in addition to pain scores, to assess the clinical and socioeconomic impact.

Opioid analgesics increase incidence of somnolence and dizziness as adverse effects of pregabalin: a retrospective study

BACKGROUND

Pregabalin, a gabapentinoid, is an adjuvant analgesic for treatment of neuropathic pain, but it has serious adverse effects such as somnolence and dizziness, particularly in elderly patients. Although decreased renal function is considered to the contributing factor for high frequency of these adverse effects in elder patients, only a few systematic clinical investigations, especially for hospitalized patients, have been performed on factors that might affect the incidence of its adverse effects. In this study, we performed a retrospective study on the effect of concomitant drugs on induction of somnolence and dizziness as adverse effects of pregabalin in hospitalized patients.

METHODS

The subjects were all pregabalin-administered patients in Shiga University of Medical Science Hospital from September 2010 to September 2012, and the subject number was 195. Multivariate logistic regression analysis was performed to determine predictors of the adverse effects, creatinine clearance, duration of pregabalin therapy, initial and maintenance doses of pregabalin, and concomitant drugs, including hypoglycemic drugs, anti-hypertensive ones, non-steroidal anti-inflammatory ones, opioids and central nervous system depressants, being used as independent variables.

RESULTS

The median initial doses of pregabalin in each renal function group were the same with the case of the defined dose. Although renal function is a well-known factor for prediction of development of adverse effects of pregabalin, we did not detect significant contribution of it. Alternatively, it was demonstrated that concomitant administration of opioids was the significant factor of the incidence of somnolence and dizziness. The first onset date of the adverse effects was frequently detected in the early days of the pregabalin therapy.

CONCLUSIONS

The fine tuning of pregabalin dosage schedule based on the renal function appeared to be critical for prevention of development of its adverse effects. Adverse effects tended to develop in the initial phase of pregabalin therapy. Concomitant administration of opioids with pregabalin has the potential to increase the incidence of adverse effects, and thus much more careful attention has to be paid especially in those situations.