Biomedical subjects

Christopher J Glynn

Publications and source records attributed to Christopher J Glynn.

4 recordsLinked to original sources

PubMed1994

Dextromethorphan for the treatment of neuropathic pain: a double-blind randomised controlled crossover trial with integral n-of-1 design.

The aim was to compare the analgesic effectiveness and adverse effect incidence of oral dextromethorphan (DM) with placebo in patients with neuropathic pain. The first 10-day treatment period was a multiple-dose double-blind randomised controlled cross-over comparison of 13.5 mg of DM 3 times a day (t.d.s.) with placebo t.d.s.: 5 treatment pairs, each pair 1 day DM and 1 day placebo. The second 10-day treatment period used 27 mg of DM t.d.s. vs. placebo, with the same design. The study incorporated a 5 pair n-of-1 design for each of the 2 doses of DM. Patients took the study medication in addition to any pre-existing analgesic regime. Patients who reported benefit could continue with DM after the study. Nineteen patients with chronic neuropathic pain were studied over two 10-day treatment periods. Outcome measures were pain intensity, pain relief, adverse effects, mood, sleep and global rating of treatment. These were recorded by daily patient diaries and by clinic assessments before and after each treatment period. There were no significant differences between DM and placebo on any of the clinic assessment outcome measures. Two patients had significantly better analgesia on more than one outcome measure on within-patient testing. One had better analgesia with DM. The other had better analgesia with placebo. Ten patients had no adverse effects on either dose of DM. Two patients withdrew during the first treatment period because of adverse effects (which included increased pain intensity), and 5 during the second period. Five patients continued with DM after the study for 1-3 months. No long-term clinical benefit was apparent in those who continued with open DM. Dextromethorphan at either 40.5 or 81 mg daily did not relieve neuropathic pain.

Adult↗

PubMed1986

Iontophoresis of vincristine versus saline in post-herpetic neuralgia. A controlled trial.

Twenty patients with post-herpetic neuralgia (median duration 28.5 months) were randomly allocated to receive transdermal iontophoresis of either vincristine or saline. Although significant improvement in pain by word score and visual analogue scale (P = 0.05) was reported by 6 out of 10 of the vincristine group, none of the patients considered themselves 'cured.' There was no significant change in the saline group. No adverse haematological or neurological side effects were seen, but skin irritation and painless electrical burns were common in both groups. The dramatic relief of pain in patients with post-herpetic neuralgia of 3 months or less reported elsewhere was not seen in our group who had pain of a longer duration. This present trial does not confirm the value of vincristine iontophoresis in the treatment of post-herpetic neuralgia of over 6 months duration.

Aged↗

PubMed1982

Clinical pharmacokinetics applied to patients with intractable pain: studies with pethidine.

The minimum effective analgetic blood concentration (MEAC) of pethidine following intravenous administration was identified in 3 patients with intractable pain. In two patients this value remained the same whether the pethidine was given intravenously, orally or rectally. In the third patient, whose eneral bioavailability was only 20%, the MEAC was not obtained. However, intramuscular administration reliably achieved the MEAC and was useful clinically. During the study period of 3-12 months, the individual patient's MEAC remained similar. Two patients developed dependence on, and tolerance to, pethidine but neither the dependence nor the tolerance appeared to be related to the MEAC. These studies confirm the importance of clinical pharmacokinetic measurements in the investigation and treatment of patients with intractable pain.

Administration, Oral↗

PubMed1981

Ventilatory response to intractable pain.

Fifty-two patients, admitted to a pain relief unit, had a cannula placed in the radial artery to measure the paO2, paCO2 and pH of arterial blood every 2 h, for periods ranging from 12 to 24 h. The patients were divided into 3 groups: 14 had low back pain, 21 patients had pain from cancer, and 17 had pain from other causes. Twenty were male and 32 were female with a mean age of 53 years (range 16-82 years). The mean paO2 of these groups was within normal limits. The mean paCO2 and pH for the 3 groups were, low back pain paCO2 4.1 kpa, pH 7.42, others, paCO2 4.2 kpa, pH 7.42. The finding of a normal pH associated with a low paCO2 suggests that patients were "reset" to a low paCO2. Treatment, which was most commonly nerve blocks, resulted in marked pain relief in 30 patients. Ten of these patients were available for follow-up at least 1 week later (4 from the low back pain group, 6 from the cancer group), and in every patient, after pain relief, there was a rise in paCO2 which was statistically significant (P less than 0.001) and was not accompanied by a fall in pH. This suggests that intractable pain is accompanied by chronic hyperventilation and that the relief of pain is accompanied by a decrease in ventilation.

Adolescent↗