Analgesics NSAIDs Opioid analgesic drugs

The drugs dealt with in this section include aspirin and other salicylates, NSAIDs, opioid analgesics, and the miscellaneous analgesics, such as nefopam and paracetamol. Table 6.1 , (p.l34) contains a listing, with a further classification of the NSAIDs. 

Alternative products to diclofenac include naproxen and mefenamic acid, both of which are non-steroidal anti-inflammatory drugs. Co-codamol is a mixture of the opioid analgesic codeine and paracetamol and it does not possess the anti-inflammatory component. It may be used in pain management either where NSAIDs are contraindicated or in patients who are intolerant to the effects of NSAIDs. 

Almost all non-opioid analgesics are non-steroidal anti-inflammatory drugs (NSAIDs) and have varying degrees of analgesic, anti-inflammatory and antipyretic activity. Acetylsalicylic acid (Aspirin ), used to relieve mild to moderate pain and certain types of severe pain, is the archetypal NSAID and is probably the best known and most used therapeutic drug worldwide. 

Clinical use Paracetamol (Ameer and Greenblatt, 1977 Clissold, 1986) has analgesic and antipyretic properties, but no relevant anti-inflammatory action. It is used for the treatment of various mild to moderate pain conditions and to reduce fever. Paracetamol is one of the most popular analgesics as a single drug or in multi-ingredient preparations, often in combination with NSAIDs or weak opioids. 

Paracetamol and opioid analgesics are safe to use in porphyria, however diclofenac is one of the drugs known to be unsafe to prescribe in porphyria. There are other NSAIDs such as ibuprofen or naproxen which are not listed as unsafe and the medical team should be advised to amend the prescription accordingly. However if Mrs JC is in severe pain it may be necessary to prescribe a strong opiate. These are safe in porphyria. 

Acute Pain A sudden uncomfortable sensation that subsides with treatment treated with nonsteroidal anti-inflammatory drugs (NSAIDs) or opioid analgesics... 

Opioid analgesics, e.g, morphine (Chapter 29), are rarely given before an operation unless the paiieni is in pain. Fentanyl and related drugs (e.g. alfcntanyh are used intravenou.sly to supplement nitrous oxide anaesthesia. These opioids are highly lipid soluble and have a rapid onset of action. They have a short duration of action because of redistribution. NSAIDs (e.g. diclofenac) may provide sufficient postoperative analgesia and do not cause respiratory depression. They can be given orally or by injection. 

These ore used particularly in the treatment of dull, poorly li alizcd (visceral) pain. Somatic pain is sharply defined and may be relieved by a weak opioid analgesic or by a non-stemitlal ami-inflammatory drug (NSAID, Chapter i2). Parenteral morphine is widely used to treat severe pain and oral morphine is the drug of choice in terminal care. 

Analgesics are divided into two groups opioids (morphine-like substances), which predominantly influence the central nervous system (CNS) and nonopioids (nonsteroidal antiinflammatory or fever-reducing drugs—NSAID), which act predominantly on the peripheral nervous system. 

Non-steroidal antiinflammatory drugs (NSAIDs) are also known as nonopioid analgesics. They relieve pain without interacting with opioid receptors and do not depress CNS and have no drug dependence or drug abuse property and possess antipyretic activity also. They act primarily on peripheral pain mechanisms and also in CNS to raise pain threshold. 

As nonsteroidal anti-inflammatory drugs (NSAIDs) exacerbate ALPE, the administration of NSAIDs should be avoided even after onset. When patients require analgesic agents, synthetic opioid agonist/antagonist analgesics (pentazocine hydrochloride or buprenorphine hydrochloride) should be administered. 

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