A multimodal (or balanced) approach to anaesthesia is a familiar concept that offers important benefits in the management
of both acute and chronic pain. Rational combinations of analgesic agents with different mechanisms of action can achieve
improved efficacy and/or tolerability and safety compared with equianalgesic doses of the individual drugs. Combining different
agents also enhances efficacy in complex pain states that involve multiple causes. Combinations of paracetamol plus a weak
opioid agent are widely used. One such combination, paracetamol plus tramadol, exploits the well-established complementary
pharmacokinetics and mechanisms of action of these two drugs. This combination has demonstrated genuine synergy in animal
studies and also combines paracetamol’s rapid onset of efficacy with tramadol’s prolonged analgesic effect. Numerous studies
have confirmed the efficacy and tolerability of paracetamol plus tramadol in both acute and chronic pain. As a single-dose
treatment for acute post-operative pain, this combination delivers rapid and sustained pain relief that is greater than either
agent alone. There is also extensive evidence for efficacy in the long-term management of chronic pain conditions, including
osteoarthritis, low back pain and fibromyalgia. In the setting of chronic pain, paracetamol plus tramadol has shown sustained
efficacy, safety and tolerability for up to 2 years without the development of tolerance. The efficacy of this combination
has been demonstrated as well in respect to reduction of pain intensity and, more importantly, with regard to improvement
of function and quality of life and the reduction of disability. Comparative trials have shown that paracetamol plus tramadol
has comparable efficacy to paracetamol plus codeine, but with reduced somnolence and constipation compared with the codeine
combination. The paracetamol plus tramadol combination is also free of organ toxicity associated with selective and non-selective
non-steroidal anti-inflammatory drugs. Hence, paracetamol plus tramadol offers an effective and well-tolerated alternative
to anti-inflammatory drugs or other paracetamol plus weak opioid combinations.
Keywords Atypical centrally acting analgesic - Dose-sparing effect - Multimodal analgesia - Opioid - Paracetamol plus tramadol - Synergistic effect