Adjuvant analgesic
| Drug and Dose | Method | Comment | References |
|---|---|---|---|
| Gabapentin | |||
| 3-day treatment with gabapentin 300 mg/day and then 600 mg/day for 2 days | Mechanical distension of rectum in 40 patients with diarrhea-predominant IBS. | Pressure pain thresholds increased. | Lee et al. (2005) |
| Pregabalin | |||
| 3 weeks' oral pregabalin titrated to a final dose of 200 mg ×3 | Rectal distension in 26 patients with IBS with rectal hypersensitivity. | Pregabalin increased the sensory thresholds for first sensation and moderate pain. | Houghton et al. (2007) |
| Escalating doses of pregabalin (300–600 mg/day) for 3 weeks | Electrical stimulation of the sigmoid with recording of corresponding evoked brain potentials in 13 patients with painful chronic pancreatitis. | Increase in pain threshold to electrical gut stimulation. No differences in evoked brain potential characteristics were seen. | Olesen et al. (2011) |
| Amitriptyline | |||
| 75 mg daily in 32 weeks | Pressure pain stimulations at the dorsum of a finger and of the temporal region of the head as well as electrical stimulation of the labial commissure of the mouth in 33 patients with chronic tension-type headache. | No significant effects. | Bendtsen and Jensen (2000) |
| 75 mg daily for 6 weeks | Mechanical pressure pain applied to vertex of the head in 24 patients with chronic tension-type headache. | The experimental pain sensitivity for mild and moderate mechanically induced pressure pain was not altered. Reduction in suprathreshold pain sensitivity for severe pain. | Göbel et al. (1994) |
| 10 mg daily in 2 months | Laser pulse stimulation in 18 patients with chronic tension-type headache. | The pain rating of laser stimulus was not different at any of the stimulated sites. The amplitude of P2 response elicited by stimulation of pericranial zones showed a reduction. | de Tommaso et al. (2006) |
| 50 mg daily for 4 weeks | Cerebral activation during rectal distension was assessed with fMRI in 19 patients with IBS. | No effect on rectal pain during distension. Reduced pain related cerebral activations in the perigenual ACC and the left posterior parietal cortex, but only during stress. | Morgan et al. (2005) |
| 10 mg at bedtime for 2 weeks, then 25 mg at bedtime for 4 weeks | Rectal distension in 12 patients with IBS. | Pain threshold to rectal distension increased. | Poitras et al. (2002) |
| Amitriptyline | |||
| 50 mg for 4 weeks | Esophageal distention in seven patients with functional dyspepsia. | No significant effect. | Mertz et al. (1998) |
| Imipramine | |||
| 25 mg for 1 week, then 50 mg for 3 weeks | Cardiac pain stimulation by right ventricular electrical stimulation and esophageal balloon distension in 22 patients with noncardiac chest pain. | Significant reduction in the prevalence of chest pain provoked by right ventricular electrical stimulation. No change in esophageal sensitivity to balloon distention. | Cannon et al. (1994) |
| Fluoxetine | |||
| 20 mg daily for 6 weeks | Rectal distension in 40 patients with IBS. | No significant effect. | Kuiken et al. 2003 |
ACC, anterior cingulate cortex.