Gabapentin and pregabalin for RSD: dosing and side effects

Reflex sympathetic dystrophy (RSD), now usually called complex regional pain syndrome (CRPS), is a chronic pain condition involving altered nerve signalling, swelling and changes in skin temperature or colour. Gabapentin and pregabalin may reduce the nerve-related component of pain for some people, but responses vary and neither medicine cures CRPS.

Both medicines are sometimes used alongside physiotherapy and other symptom treatments. An Australian GP is usually the starting point, with Medicare rebates covering part of consultation fees and referrals to public or private pain services; waiting lists and out-of-pocket costs vary, particularly in Melbourne and Brisbane.

Understanding RSD and reaching a diagnosis

CRPS can cause burning, shooting or electric pain, sensitivity to light touch, swelling, and changes in skin colour, temperature or sweating. Stiffness, tremor and difficulty moving may also develop. Diagnosis depends on the pattern of symptoms and signs, usually including pain that is disproportionate to the original trigger.

There is no single blood test or scan that confirms CRPS. A clinician examines the affected area and checks for alternatives such as arthritis, infection, thrombosis or nerve injury. Imaging may exclude other causes but does not diagnose CRPS by itself. Brooks County health information provides a broader patient-oriented overview of symptoms and daily impact.

The trigger may be a fracture, sprain, surgery or prolonged immobilisation, although sometimes no clear event occurs. Changes in pain processing, immune activity and circulation are thought to contribute. Anxiety and low mood can coexist with persistent pain, but they do not mean the physical symptoms are imagined.

Dosing and side effects in practice

There is no established CRPS-specific dose, and gabapentin and pregabalin are not interchangeable. Common Australian neuropathic-pain regimens start gabapentin at around 100–300 mg daily in divided doses and pregabalin at 25–75 mg once or twice daily. These are prescribing examples, not instructions for self-treatment; titration depends on response, kidney function and other medicines.

• Increase slowly at the prescribed intervals, as rapid escalation increases sleepiness and dizziness.
• Adjust for kidney function, because reduced clearance can make adverse effects more likely.
• Follow the exact prescription. Gabapentin and pregabalin doses cannot be matched milligram for milligram.
• Do not double a missed dose or stop suddenly. Seek a prescriber-guided taper if treatment is no longer needed.

Benefit is judged over days to weeks rather than after a single capsule. Gabapentin often needs several days at each dose level, while pregabalin may be felt sooner. A symptom diary can show whether pain, sleep or movement is improving.

Possible adverse effects include drowsiness, dizziness, blurred vision, unsteadiness, nausea, weight gain and ankle swelling. Reactions differ, and side effects often become more noticeable as the dose rises.

• Drowsiness, dizziness, blurred or double vision and unsteadiness.
• Nausea, abdominal discomfort, dry mouth or fatigue.
• Weight gain and ankle swelling, sometimes noticed because shoes feel tighter.
• Difficulty concentrating, memory problems or mood changes.
• Seek urgent medical assessment for a severe rash, breathing difficulty or markedly reduced consciousness.

Alcohol can compound sedation, and combining these medicines with opioids, benzodiazepines or sleeping tablets needs prescriber review. In Australia, do not drive if drowsy or otherwise affected; check state or territory licensing rules, especially for commercial drivers. Both medicines are Schedule 4 prescription drugs, and Pharmaceutical Benefits Scheme subsidy depends on the indication and prescription. The Therapeutic Goods Administration has also warned about unapproved medicines sold through unverified online suppliers.

What these medicines can and cannot do

Gabapentin and pregabalin affect calcium channels and reduce the release of some nerve signalling chemicals. They may ease neuropathic burning or shooting pain, but they do not directly repair damaged nerves, resolve all swelling or reverse circulation changes. Evidence specifically for CRPS is more limited than for some other neuropathic pain conditions.

A useful response may mean less burning pain, better sleep or easier movement rather than complete pain relief. If an adequate trial at a tolerable dose produces little benefit, the prescriber may adjust the approach instead of continuing indefinite escalation.

The choice between the two medicines depends on response, adverse effects, kidney function, interactions and cost. One is not automatically more suitable for RSD, and availability through the PBS does not determine which will work better for an individual.

Rehabilitation and emotional support

Rehabilitation remains central to CRPS management. Individual, graded physiotherapy, gradual desensitisation and mirror therapy for suitable patients may help movement and confidence. Occupational therapists can suggest changes to work tasks, household activities and sleep routines. Exercise should not involve forcing a painful or markedly swollen limb.

Chronic pain can disrupt sleep, work, relationships and mood. Cognitive behavioural therapy or acceptance and commitment therapy can help with coping and functioning; these approaches do not imply that the pain is psychological. Peer support groups may also provide practical advice and reduce isolation.

Access varies across Australia. For someone in regional or rural Australia, telehealth can connect them with a pain specialist, while rehabilitation may still require a local physiotherapist or occasional travel to a larger centre. An Australian chemist can suggest repeat-packing or dosette options for irregular work shifts, making a complicated dosing schedule easier to follow.

Planning treatment with your clinician

A GP can coordinate a plan with a neurologist, pain specialist and rehabilitation team. Agree on what success means—such as less pain, better sleep or easier walking—and set a review date. Record current prescription medicines, supplements and over-the-counter products, because interactions and duplicated medicines can matter.

When several providers are involved, ask who can access your records and how you can correct errors. The technical idea of keeping information under closer local control is illustrated by distributed edge storage.

Review both benefit and side effects after the agreed trial, and make dose changes through the treating clinician rather than by stopping treatment abruptly. Book a GP review, bring your medication list and symptom diary, and establish a written dosing and follow-up plan before making any changes.