Comparison of a needle-free high-pressure injection system with needle-tipped injection of intracavernosal alprostadil for erectile dysfunction.

Patients identified from hospital records as using alprostadil injections for erectile dysfunction were invited to take part in this open crossover study. On alternate weeks eight patients were given intracavernosal needle injections and transdermal needle-free injection of alprostadil in a randomized order. Efficacy of injection and associated pain were assessed and compared for the two methods. Pain produced during injection was significantly greater with the needle-free system than with the needle-tipped injection whilst efficacy was significantly less. Bruising was reported in all except one patient following needle-free injection only. Patient ratings of the needle-free injector were significantly lower than ratings for needle-tipped alprostadil delivery and when asked to express a preference, every patient chose the needle-tipped injection over the needle-free device.

Characterization of secondary hyperalgesia produced by topical capsaicin jelly--a new experimental tool for pain research.

Peripheral administration of the nociceptive agent capsaicin is used as an experimental tool to study neurophysiological and pharmacological aspects of the generation and control of pain. When investigating secondary hyperalgesia phenomena, current topical and intradermal capsaicin delivery methods have two key limitations. Intradermal injection can evoke severe chemogenic pain and both delivery methods produce an unstable area of dynamic mechanical allodynia. We present validity studies of a new preparation for capsaicin delivery that overcomes these limitations. The novel capsaicin formulation consists of a water-based semisolid jelly preparation containing 1% capsaicin which is applied topically under adhesive-free occlusion to a small area of the skin. We demonstrate that in healthy human subjects this model evokes areas of flare, punctate hyperalgesia and mechanical allodynia which are equivalent to established models and that these areas are stable over time and reproducible on repeat experiments. The jelly formulation evokes only minimal chemogenic pain and, as the preparation remains in situ throughout the study providing constant capsaicin exposure, a stable area of dynamic mechanical allodynia is produced. These validation studies show that this novel capsaicin administration method is a practical, reliable and viable tool for investigating experimental secondary hyperalgesia.

Information technology and general practice. A survey of general practitioner attitudes towards computerisation.

AIM: General practitioners in the central Sydney area were surveyed to quantify the extent of, and attitudes towards, computerisation in Australian general practice. METHOD: Two surveys were mailed to all GPs in the central Sydney area, first in 1994, and again in 1996. The majority of questions in both surveys were identical. The results were collated and descriptive and comparative statistics calculated. RESULTS: There was an increase in the use of computers for clinical tasks and, GPs' attitudes towards computerised prescribing systems became more positive. There was a persistent negative attitude towards the actual costs of computerisation. CONCLUSION: Methods are now required to transform the increased use of computers by GPs into improved outcomes for them and their patients.

Voltage-dependent calcium channel subtypes controlling somatic substance P release in the peripheral nervous system.

1. Isolated rat dorsal root ganglia (DRG) neurones support vesicular, non synaptic release of substance P in a depolarisation and Ca2+ dependent manner. 2. In vivo this process may mediate cross-communication between DRG cells in some neuropathological conditions and is therefore a putative area for drug intervention. 3. The authors investigated the voltage-dependent Ca2+ channel (VDCC) subtypes involved in somatic release of substance P. Fresh (< 1 day) cultures of DRG neurones were incubated with high K+ depolarising saline in the presence and absence of subtype selective VDCC blockers. Substance P released into the external media was collected and quantified using a radioimmunoassay. 4. The results show that L-type and N-type, but not P-type, VDCCs play an important role in high K+ evoked substance P release from rat DRG neurones.