Table 1 Dosage adjustment of pregabalin based on renal clearance20 Creatinine clearance (ml/min) Total daily dose of pregabalin (mg/day) 60 150 300 450 30–59 75 150 225 15–29 25–50 75 100–150 15 25 25–50 50–75 Supplemental dose after HDa 25–50 50–75 75–100 aSupplemental dose after hemodialysis is a single dose to be administered after each 4-hour hemodialysis session. Abbreviation: HD, hemodialysis. 600 300 150 75 100–150 Pregabalin for postherpetic neuralgia Total daily dose to be divided 2–3 times daily 2–3 times daily Once or twice daily Once daily clinical trials involving patients with PHN, and 1 randomized, double-blind, placebo-controlled study in patients with chronic neuropathic pain including PHN.7,14,18,25 Studies comparing PGB with other agents used to treat PHN are not available. Patients failing to respond to gabapentin were excluded from most of these studies.7,14,18 An important point to note: all 4 trials described herein were sponsored by the manufacturer of PGB (Pﬁzer), and the trials were conducted at least in part by Pﬁzer employees. An 8-week trial was conducted in 173 patients with PHN, deﬁned as pain persisting for 3 months following the healing of a HZ rash.14 Concomitant medications that were allowed at stable doses during the trial included opioid and non-opioid analgesics, NSAIDs, aspirin, acetaminophen ( 4 g/day), and antidepressants including SSRIs. Benzodiazepines, skeletal muscle relaxants, oral steroids, local and topical agents for PHN, and anticonvulsants were prohibited. Patients were randomized to either PGB (n = 89) or placebo (n = 84). Doses were given three times a day. Those on PGB received either 600 mg/day (CrCl 60 mL/min) or 300 mg/day (CrCl 30–60 mL/min). This renal dosage adjustment is based on pharmacokinetic studies that demonstrated comparable steady-state concentra- tions of PGB, thus allowing these 2 subsets to be combined as a single PGB treatment arm for the purpose of pain relief assessment.14,15 Mean age of the patients was 71.5 years, with 82% of patients over 65 years of age, and the mean duration of PHN was 33.8 months. Patients were required to have an average daily pain score of at least 4 on an 11-point numerical rating scale (0 = no pain; 10 = worst possible pain) during the 7-day baseline period. Additionally, patients were required to have a pain score of 40 mm on the 100 mm visual analog scale (VAS) of the Short-Form McGill Pain Questionnaire (SF-MPQ) at baseline and at randomization. The primary efﬁcacy point was the mean of the last 7 daily pain scores on the 11-point pain scale. Patients treated with PGB had greater reductions in mean pain scores than those treated with placebo (3.60 versus 5.29; p 0.0001). A decrease in pain was seen Clinical Interventions in Aging 2009:4 in PGB-treated patients as early as day 1 and maintained throughout the study. In addition, signiﬁcantly more patients receiving PGB had 50% reduction in mean pain scores than those receiving placebo. As a secondary endpoint, daily sleep interference scores were measured for all study participants by assessing the degree to which pain interfered with sleep during the previous 24 hours on an 11-point numerical rating scale. A score of 0 indicates pain did not interfere with sleep, and a score of 10 indicates pain completely interfered with sleep. Sleep interference scores were recorded in subjects’ daily diaries upon awakening. Signiﬁcant improvements in mean sleep interference scores (derived from subjects’ last 7 days of diary entries while receiving study drug) were observed. At study end, the mean sleep interference score was 1.93 in PGB-treated patients versus 3.51 in placebo-treated subjects (p = 0.0001).14 A second 8-week trial was conducted in 238 patients with PHN of 6 months in duration after the healing of the HZ rash.7 Concomitant medications that were allowed at stable doses during the study period included NSAIDs, acetaminophen, opioid and non-opioid analgesics, and antidepressants. Anticonvulsants and benzodiazepines had to be discontinued at least 14 days prior to receiving study medication. Patients with a CrCl 30 mL/min were excluded from the trial. Patients were randomized to either PGB 150 mg/day (n = 81), PGB 300 mg/day (n = 76), or placebo (n = 81). Doses were given three times a day. Mean age of the patients was similar to those in the study by Dworkin and colleagues (73.2 years, 71.3, and 71.9 years for the placebo, 150 mg/day, and 300 mg/day groups, respectively), and the mean duration of PHN ranged from 44.8 to 40.7 months for the placebo, 150 mg/day, and 300 mg/day groups respec- tively. Patients were required to have an average daily pain score of at least 4 on an 11-point numerical rating scale (0 = no pain; 10 = worst possible pain) during the 7-day baseline period. In addition, patients were required to have a score of 40 mm on the 100 mm VAS of the SF-MPQ at 19