Pain Relief

The word pain when used in a medical sense usually refers to either acute pain or chronic pain. Acute pain is often severe pain that has an obvious and reversible cause (such as a broken leg) and may only require that the cause of said pain is addressed in order for the pain to go away

Chronic pain usually stems from a condition or number of conditions that are either difficult to diagnose, or difficult to treat, or both. Chronic pain often takes longer than acute pain to be remedied and can stem from illnesses such as cancer or neuropathy.

Pain pathways are often set to keep transmitting a painful sensation even though the condition that originally caused the pain has been cured. In this case, the treatment goal will focus on the pain itself as an illness in its own right.

Pain management is a diverse, multidisciplinary field. Drug treatments for pain include analgesics and narcotics, as well as non-steroidal anti-inflammatory drugs (NSAIDS), some antidepressants and anticonvulsant medications. Non-drug therapies center around physical therapy and exercise, hot and cold treatments, and psychotherapy.

Analgesics are any drugs used to treat pain as a symptom. They are a wide-ranging group of treatments that act in a variety of different ways in order to achieve this goal, including interfering in the central and peripheral nervous system. Paracetamol is a common analgesic, as are various NSAIDS such as aspirin and ibuprofen.

Narcotics like morphine and other synthetic drugs with similar qualities and properties to narcotics (such as tramadol) are also often used. Types of drugs which are sometimes used in the treatment and management of pain, but not generally considered to be analgesics, include some anticonvulsant medications and tricyclic andtidepressants.

The mechanism of one of the most used analgesics, paracetamol, is still being investigated, but consensus is that it acts upon the central nervous system somehow in order to suppress pain. Non-steroidal anti-inflammatory drugs, such as aspirin, work to decrease the production of prostaglandin by inhibiting cyclooxygenase. This has the double effect of reducing pain and also reducing inflammation. Paracetamol and opiates merely relieve pain.

Paracetamol is commonly used because it has few reported side-effects, although overdosing is not recommended due to the possibility of liver damage through hepatoxicity.

Non-steroidal anti-inflammatory drugs have several potential side-effects, including but not limited to, peptic ulcers, allergic reaction, temporary or permanent loss if hearing, and renal failure. They can also increase the risk of hemorrhaging, which makes them unsuitable for use in some cases.

NSAIDs work to inhibit the enzyme cyclooxygenase, which has at least two types, referred to as COX1 and COX2. studies indicated that most of the beneficial effects of NSAIDS were achieved by blocking the COX2 enzyme, and most of the unwanted side-effects were as a result of the inhibition of the COX1 enzyme, therefore newer kinds of NSAID have been developed which only inhibit the COX2 type. Such drugs, including celecoxib and rofecoxib, achieve the same analgesic effects as older types of non steroidal anti inflammatory drugs, but without some of the more serious side-effects, including the increased risk of gastro-intestinal hemorrhaging.

The primary opioid used in pain management is still morphine. Other common variations on the opioid theme include codeine, oxycodone, diamorphine and hydrocodone. All have a similar effect on their primary target, the cerebral opioid receptor system.

The drugs buprenorphine and tramadol are similarly believed to act as partial agonists of the opioid receptors. For patients who react well to opioids, they can be administered virtually as and when required, as much as needed. Some patients however may experience opioid toxicity, characterized by respiratory depression, jerking and confusion, and pinpoint pupils. In such cases the dosage of opioids should be limited and monitored, and if possible alternative treatments sought.

Opioids are a popular choice as analgesics because of their high effectiveness. But they must also be used carefully, and patients being started on treatment using opiates should be carefully monitored. Possible side-effects include nausea, vomiting and constipation, and bad itching that may necessitate a change of medication.

Barring these potential side-effects, the use of opioids and other narcotics to assist in pain management is quite safe and effective, though sometimes a patient will have to be ‘weaned’ off a particular painkiller because of its addictive properties.

Tricyclic antidepressants, otherwise known simply as tricyclics or TCAs, are particularly effective painkillers for neurological or neuropathic pain. They are thought to have an effect on serotonin levels in the brain, which modulates the opioid systems in the central nervous system. Pain relief using tricyclics usually involves a lower dose than that which would have been needed to treat depression or another psychiatric disorder.

Barbiturates are an older type of drug that belong to a family of painkillers known as central nervous system depressants. As such, they can produce a wide range of consequences, from mild sedation to extensive anesthesia. Shorter acting barbiturates are sometimes prescribed as sleeping pills, but non-benzodiazepines have largely taken over from them in this area.

Benzodiazepines are also known as benzodiazepine receptor agonists, or BzRAs. They are very commonly prescribed to treat conditions where some form of sedation is required, such as those that require pain relief, or sleep disorders. They work by non-selectively targeting particular receptor sights in the brain which modulate the effect of GABA, or gammaaminobutyric acid, which is a neurotransmitter.

Popular benzodiazepines include alprazolam, temazepam and flunitrazepam, or to give them their commercial names, Xanax, Restoril and Rohypnol.

Benzodiazepines can also be used in the treatment of anxiety, and lorazapam and diazepam are sometimes given intravenously to treat patients who experience panic attacks.

Because of their strong sedative effects, benzodiazepines should not be used by people who are actively doing anything that may become dangerous should their senses become impaired, such as driving.

For this reason though, they make excellent treatments for insomina.

Sedatives used for this purpose should be used on a short-term basis however, since dependance and tolerance may occur.

Benzodiazepines are also useful to sedate patients prior to surgery, especially those who are experiencing anxiety. They can also cause amnesia as a possible side-effect, which can actually be helpful for some patients, who would rather not remember their surgical experience anyway.

The particular choice of sedative in dental surgery is Lorazepam. Alternatively nitrous oxide may be used, which is faster acting, yet shorter lasting.