Pain Relief Pharmacy

A nerve block relieves pain by interrupting how pain signals are sent to your brain. It is done by injecting a substance, such as alcohol or phenol, into or around a nerve or into the spine.

Nerve blocks may be used for several purposes, such as:

• To determine the source of pain.
• To treat painful conditions.
• To predict how pain will respond to long-term treatments.
• For short-term pain relief after some surgeries and other procedures.
• For anesthesia during some smaller procedures, such as finger surgery.

Nerve blocks are used to treat chronic pain when drugs or other treatments do not control pain or cause bad side effects. A test block is usually performed with local anesthetic. If you achieve good pain relief from the local anesthetic, your doctor may inject a nerve block, such as alcohol or phenol.

What To Think About

Doctors have begun to use extreme cold or heat in nerve blocks instead of drugs or chemicals. Cryoanalgesia is the use of extreme cold. A probe is placed very close to the nerve, and the temperature is lowered for 60 to 120 seconds, often in several cycles. Radiofrequency denervation is the use of extreme heat. A probe is placed close to the nerve, and radio waves are used to generate extreme heat at the tip of the probe for 40 to 90 seconds.

A nerve block may cause temporary muscle paralysis or a loss of all feeling in the affected area or in the surrounding area.

Although nerve blocks can improve pain control, they do not help people to live longer.

Treatment Overview

Treatment for neck pain consists of reducing the pain with ice and medication, improving neck movement and flexibility with exercises or physical therapy, and avoiding further neck injury by changing activities and body mechanics, such as how you sit or sleep. The specific treatment may depend on whether your neck pain is caused by activities, an injury, or another medical condition. Home treatment is often all that is needed for neck pain.

Because most neck pain is caused by repeated or prolonged movements to the neck’s muscles, ligaments, tendons, bones, or joints, nonsurgical treatment is usually effective. Most cases of neck pain caused by activities resolve within 4 to 6 weeks.

Acute neck pain

For sudden (acute) neck pain:

• Place an ice pack or cold pack over painful muscles for 24 to 48 hours. This will help decrease any pain, muscle spasm, or swelling. If the problem is near the shoulder or upper back, ice the back of the neck. If you prefer, try ice massage. Massage the painful area with ice for 2 to 7 minutes, long enough to numb the pain. Ice frozen in a Styrofoam cup works well. Be sure not to damage your skin (frostbite).
• Avoid things that might increase swelling, such as hot showers, hot tubs, hot packs, or alcoholic beverages, for the first 48 hours after an injury. After 48 to 72 hours, if swelling is gone, apply heat. Use a warm pack or heating pad set on low. Some experts recommend alternating between heat and cold treatments.
• Return to your normal daily activities as soon as possible. Research suggests that continuing normal activities after a neck-strain injury helps resolve some symptoms faster than taking time off from work and using neck immobilization.
• Gently massage or rub the area to relieve pain and encourage blood flow. Do not massage the injured area if it causes pain. Nonprescription creams or gels, such as Bengay, may provide pain relief.
• Take pain relievers. Nonsteroidal anti-inflammatory drugs, including aspirin (such as Bayer), ibuprofen (such as Advil), or naproxen sodium (such as Aleve), can help relieve pain and reduce inflammation. Do not give aspirin to anyone younger than 20 because of the risk of Reye’s syndrome. Acetaminophen (such as Tylenol) can help relieve pain.

For severe pain or muscle spasm, your doctor also may prescribe:

• Muscle relaxants, which treat severe pain spasms when neck pain begins. They include diazepam (Valium), cyclobenzaprine (Flexeril), and carisoprodol (Soma).
• Narcotic pain relievers, which are used short-term for severe neck pain. They include codeine, acetaminophen and hydrocodone (Vicodin, Lortab), aspirin and oxycodone (Percodan), and acetaminophen and oxycodone (Percocet).

The treatment that is right for you may be different from the treatment for someone else with neck pain. Some treatments have been studied more than others. Many treatments for neck pain haven’t been very well researched, even if they are used a lot. A review of multiple studies shows that exercise and manual therapy, used either separately or together, are likely to be beneficial in the treatment of uncomplicated neck pain.

Your health professional may recommend that you wear a cervical collar to support your neck. Cervical collars may reduce neck pain, but they should be used only for a day or two. See an illustration of a cervical collar.

Chronic neck pain

For long-lasting (chronic) neck pain, you can use the same treatment used for acute pain, although you do not have to worry about swelling. Your health professional may prescribe other medications, such as antidepressants. These include doxepin (Sinequan) and amitriptyline (Elavil, Endep).

You can aid healing and prevent further injury by:

• Having physical therapy. For home treatment, you can use heat and massage. A physical therapist can teach you exercises to do at home. These can keep your neck flexible and strong and prevent stiffness.
• Changing or avoiding any activities that may be causing your neck pain, such as prolonged computer work or overhead work.
• Maintaining good health habits. If possible, reduce stress and tension at work and home. Stop smoking; smoking slows healing because it decreases blood supply and delays tissue repair. Exercise regularly, including aerobic exercise such as walking. For more information, see the topics Stress Management, Quitting Tobacco Use, and Fitness.
• Trying manual therapy. A trained practitioner may use slow twisting, pulling, or pushing movements. When slow, measured movements are used, it is known as “mobilization.” Avoid rapid, forceful movements, which are known as “manipulation.” Talk to your doctor before trying manual therapy.

Surgery

Surgery is rarely required for neck pain. It may be considered to treat neck pain caused by pressure on the nerve roots or spinal cord, a severe injury that has broken a neck bone (vertebra), a tumor, infection, or a spinal condition such as narrowing of the spinal canal (cervical spinal stenosis) or arthritis of the neck (cervical spondylosis). Surgical options include:

• Discectomy (with or without fusion). For more information on discectomy, see the Surgery section of the topic Herniated Disc.
• Cervical spinal fusion, in which selected bones in the neck are joined (fused) together.
• Spinal decompression, in which pressure is reduced on the spinal cord or spinal nerve roots by removing part of a bone or disc.

What To Think About

A review of studies reports that:

• Exercise reduced pain better than medication for muscle pain or spasm, stress management, or no exercise.
• There is not enough evidence to determine whether medications, transcutaneous electrical nerve stimulation (TENS), ice and heat, soft cervical collars, or special pillows are helpful for neck pain.

In one small study, women with chronic neck pain were taught and used neck endurance and strengthening exercises for 1 year. Compared with people who had chronic neck pain and were not using the exercises, the exercise group had less pain and disability.

Keeping your neck moving improves its function and helps it heal. In general, cervical collars are only used after a surgery or for a day or two after a neck sprain.

People who have chronic pain syndrome and its associated problems, such as depression or drug dependence, may respond to treatment more slowly. Counseling in addition to medical treatment may help in recovery.

What is anesthesia?

Anesthesia controls pain during surgery or other medical procedures. It includes using medicines, and sometimes close monitoring, to keep you comfortable. It can also help control breathing, blood pressure, blood flow, and heart rate and rhythm, when needed.

An anesthesiologist or a nurse anesthetist takes charge of your comfort and safety during surgery. This topic focuses on anesthesia care that you get from these specialists.

Anesthesia may be used to:

• Relax you.
• Block pain.
• Make you sleepy or forgetful.
• Make you unconscious for your surgery.

Other medicines also may be used to relax your muscles during surgery.

What are the types of anesthesia?

• Local anesthesia numbs a small part of the body. You get a shot of local anesthetic directly into the surgical area to block pain. It is used only for minor procedures. You may stay awake during the procedure, or you may get medicine to help you relax or sleep.
• Regional anesthesia blocks pain to a larger part of your body. Anesthetic is injected around major nerves or the spinal cord. You may get medicine to help you relax or sleep. Major types of regional anesthesia include:
  • Peripheral nerve blocks. A nerve block is a shot of anesthetic near a specific nerve or group of nerves. It blocks pain in the part of the body supplied by the nerve. Nerve blocks are most often used for procedures on the hands, arms, feet, legs, or face.
  • Epidural and spinal anesthesia. This is a shot of anesthetic near the spinal cord and the nerves that connect to it. It blocks pain from an entire region of the body, such as the belly, hips, or legs.
• General anesthesia affects the brain as well as the entire body. You may get it through a vein (intravenously), or you may breathe it in. With general anesthesia, you are completely unaware and do not feel pain during the surgery. General anesthesia also often causes you to forget the surgery and the time right after it.

What determines the type of anesthesia used?

The type of anesthesia used depends on several things:

• Your past and current health. The doctor or nurse will consider other surgeries you have had and any health problems you have, such as diabetes. You also will be asked whether you or any family members have had an allergic reaction to any anesthetics or medicines.
• The reason for your surgery and the type of surgery.
• The results of tests, such as blood tests or an electrocardiogram.

Your doctor or nurse may prefer one type of anesthesia over another for your surgery. In some cases, your doctor or nurse may let you choose which type to have. Sometimes, such as in an emergency, you do not get to choose.

What are the potential risks and complications of anesthesia?

Major side effects and other problems of anesthesia are not common, especially in people who are in good health overall. But all anesthesia has some risk. Your specific risks depend on the type of anesthesia you get, your health, and how you respond to the medicines used.

Some health problems increase your chances of problems from anesthesia. Your doctor or nurse will identify any health problems you have that could affect your care.

Your doctor or nurse will closely watch your vital signs, such as your blood pressure and heart rate, during anesthesia and surgery, so most side effects and problems can be avoided.

How should you prepare for anesthesia?

Make sure you get a list of instructions to help you prepare for your surgery. Your surgeon will also let you know what will happen when you get to the clinic or hospital, during surgery, and afterward.

Your doctor will tell you when to stop eating and drinking before your surgery. When you stop depends on your health problem and the type of anesthesia that will be used. If you take any medicines regularly, ask your doctor or nurse if you should take your medicines on the day before or the day of your surgery.

You have to give your consent to be given anesthesia. Your doctor or nurse will discuss the best type of anesthesia for you and review risks, benefits, and other choices.

Many people are nervous before they have anesthesia and surgery. Mental relaxation methods as well as medicines can help you relax.

What happens when you are recovering from anesthesia?

Right after surgery you will be taken to the recovery room. Nurses will care for you there under the direction of an anesthesiologist. A nurse will check your vital signs and any bandages and ask about how much pain you have. If you are in pain, don’t be afraid to say so.

Some effects of anesthesia may last for many hours after surgery. If you had local or regional anesthesia, you may have some numbness or reduced feeling in part of your body. Your muscle control and coordination may also be affected.

Other common side effects of anesthesia are closely watched and managed to reduce your discomfort. These side effects include:

• Nausea and vomiting. In most cases, this can be treated and does not last long.
• A mild drop in body temperature. You may feel cold and may shiver when you first wake up.

For minor surgeries, you may go home the same day. For more complicated surgeries, you may have to move to a hospital room to continue your recovery. If you stay in the hospital, your doctor or nurse will visit you to check on your recovery from anesthesia and answer any questions you have.

Types of Anesthesia

Anesthesia involves the use of medications to block pain sensations (analgesia) during surgery and other medical procedures. Anesthesia also reduces many of your body’s normal stress reactions to surgery.

The type of anesthesia used for your surgery depends on:

• Your medical history, including other surgeries you have had and any conditions you have (such as diabetes). You will also be asked whether you have had any allergic reactions to any anesthetics or medications or whether any family members have had reactions to anesthetics.
• The results of your physical examination. A physical exam will be done to evaluate your current health and identify any potential risks or complications that may affect your anesthesia care.
• Tests such as blood tests or an electrocardiogram, if needed.
• The type of surgery that you are having.
  • You need to be able to lie still and remain calm during surgery done with local or regional anesthesia.
  • Young children usually cannot stay still during surgery and need general anesthesia.
  • Adults who are extremely anxious, in pain, or have muscle disorders also may have difficulty remaining relaxed and cooperative.
  • Some surgical procedures require specific positions that may be uncomfortable for long periods if you are awake.
  • Some procedures require the use of medications that cause muscle relaxation and affect your ability to breathe on your own. In such cases, your breathing can best be supported if general anesthesia is used.

Based on your medical condition, your anesthesia specialist may prefer one type of anesthesia over another for your surgery. When the risks and benefits of different anesthesia options are equal, your anesthesia specialist may let you choose the type of anesthesia.

Anesthesia methods

There are several ways that anesthesia can be given.

• Local anesthesia involves injection of a local anesthetic (numbing agent) directly into the surgical area to block pain sensations. It is used only for minor procedures on a limited part of the body. You may remain awake, though you will likely receive medicine to help you relax or sleep during the surgery.
• Regional anesthesia involves injection of a local anesthetic (numbing agent) around major nerves or the spinal cord to block pain from a larger but still limited part of the body. You will likely receive medicine to help you relax or sleep during surgery. Major types of regional anesthesia include:
  • Peripheral nerve blocks. A local anesthetic is injected near a specific nerve or group of nerves to block pain from the area of the body supplied by the nerve. Nerve blocks are most commonly used for procedures on the hands, arms, feet, legs, or face.
  • Epidural and spinal anesthesia. A local anesthetic is injected near the spinal cord and nerves that connect to the spinal cord to block pain from an entire region of the body, such as the abdomen, hips, or legs.
• General anesthesia is given into a vein (intravenously) or is inhaled. It affects the brain as well as the entire body. You are completely unaware and do not feel pain during the surgery. In addition, general anesthesia often causes forgetfulness (amnesia) right after surgery (postoperative period).

For some minor procedures, a qualified health professional who is not an anesthesia specialist may give some limited types of anesthesia, such as procedural sedation. Procedural sedation combines the use of local anesthesia with small doses of sedative or analgesic agents (painkillers) to relax you.

Medications used for anesthesia

A wide variety of medications are used to provide anesthesia. Their effects can be complex, and they can interact with other medications to cause different effects than when they are used alone. Anyone receiving anesthesia—even procedural sedation—must be monitored continuously to protect and maintain vital body functions. The complex task of managing the delivery of anesthesia medications as well as monitoring your vital functions is done by anesthesia specialists.

Medications used for anesthesia help you relax, help relieve pain, induce sleepiness or forgetfulness, or make you unconscious. Anesthesia medications include:

• Local anesthetics, such as lidocaine (Xylocaine) or bupivacaine (Marcaine), that are injected directly into the body area involved in the surgery.
• Intravenous (IV) anesthetics, such as sodium thiopental (Pentothal), midazolam (Versed), propofol (Diprivan), or fentanyl (Sublimaze), that are given through a vein.
• Inhalation anesthetics, such as isoflurane and nitrous oxide, that you breathe through a mask.

Other medications that are often used during anesthesia include:

• Muscle relaxants, which block transmission of nerve impulses to the muscles. They are used during anesthesia to temporarily relax muscle tone as needed.
• Reversal agents, which are given to counteract or reverse the effects of other medications such as muscle relaxants or sedatives given during anesthesia. They may be used to reduce the time it takes to recover from anesthesia.

Risks and Complications

Although all types of anesthesia involve some risk, major side effects and complications from anesthesia are uncommon. Your specific risks depend on your health, the type of anesthesia used, and your response to anesthesia.

Personal risk factors

Your age may be a risk factor. In general, the risks associated with anesthesia and surgery increase in older people.

Certain medical conditions, such as heart, circulation, or nervous system problems, increase your risk of complications from anesthesia.

Complications from local anesthesia

When used properly, local anesthetics are safe and have few major side effects. However, in high doses local anesthetics can have toxic effects caused by being absorbed through the bloodstream into the rest of the body (systemic toxicity). This may significantly affect your breathing, heartbeat, blood pressure, and other body functions. Because of these potential toxic effects, equipment for emergency care must be immediately available when local anesthetics are used.

Complications from regional anesthesia

For regional anesthesia, an anesthetic is injected close to a nerve, a bundle of nerves, or the spinal cord. In rare cases, nerve damage can cause persistent numbness, weakness, or pain.

Regional anesthesia (regional nerve blocks, epidural and spinal anesthesia) also carries the risk of systemic toxicity if the anesthetic is absorbed through the bloodstream into the body. Other complications include heart or lung problems, and infection, swelling, or bruising (hematoma) at the injection site.

Spinal anesthesia medication is injected into the fluid that surrounds the spinal cord (cerebrospinal fluid). The most common complication of spinal anesthesia is a headache caused by leaking of this fluid. With current techniques of giving spinal anesthesia, this occurs in about 1% to 2% of all people who have spinal anesthesia and is more common in younger people. A spinal headache may be treated quickly with a blood patch to prevent further complications; a blood patch involves injecting a small amount of the person’s own blood into the area where the leak is most likely occurring to seal the hole and to increase pressure in the spinal canal and relieve the pull on the membranes surrounding the canal.

Complications from general anesthesia

Serious side effects of general anesthesia are uncommon in people who are otherwise healthy. However, because general anesthesia affects the whole body, it is more likely to cause side effects than local or regional anesthesia. Fortunately, most side effects of general anesthesia are minor and can be easily managed.

General anesthesia suppresses the normal throat reflexes such as swallowing, coughing, or gagging that prevent aspiration. Aspiration occurs when an object or liquid is inhaled into the respiratory tract (the windpipe or the lungs). To help prevent aspiration, an endotracheal (ET) tube may be inserted during general anesthesia. When an ET tube is in place, the lungs are protected so stomach contents cannot enter the lungs. Aspiration during anesthesia and surgery is very uncommon. People are usually instructed not to eat or drink anything for a specific number of hours before anesthesia so that their stomach is empty to reduce this risk. Anesthesia specialists use many safety measures to minimize the risk of aspiration in all patients.

Insertion or removal of airways may cause respiratory problems such as coughing; gagging; or muscle spasms in the voice box, or larynx (laryngospasm), or in the bronchial tubes in the lungs (bronchospasm). Insertion of airways also may cause an increase in blood pressure (hypertension) and heart rate (tachycardia). Other complications may include damage to teeth and lips, swelling in the larynx, sore throat, and hoarseness caused by injury or irritation of the larynx. Other serious risks of general anesthesia include changes in blood pressure or heart rate or rhythm, heart attack, or stroke. Death or serious illness or injury due solely to anesthesia is rare and is usually also related to complications from the surgery. Death occurs in about 1 in 250,000 people receiving general anesthesia, although risks are greater for those people with serious medical conditions.¹

Some people who are going to have general anesthesia express concern that they will not be completely unconscious but will “wake up” and have some awareness during the surgical procedure. But awareness during general anesthesia is very rare because anesthesia specialists devote careful attention and use many methods to prevent this.

Risks from reactions to anesthetic medications

Some anesthetic medications may cause allergic or other abnormal reactions in some people, but these are rare. If you suspect you may have such a problem, you should bring this to the attention of both your surgeon and anesthesia specialist well before your surgery. Testing will then be arranged as necessary.

A rare, potentially fatal condition called malignant hyperthermia (MH) may be triggered by some anesthetics. The anesthetics most commonly associated with malignant hyperthermia include the potent inhalation anesthetics and the muscle relaxant succinylcholine. For more information, see the listing for the Malignant Hyperthermia Association of the United States (MHAUS) in the Other Places to Get Help section of this topic.

Many people living with chronic pain are daunted by the prospect of long term or even permanent drug therapy. What are these drugs, are they safe and how do they work? Concerns such as these can stop people perservering with medicines that may offer a real life enhancing solution to their condition.In this article Dr. Mick Serpell explains how amitriptyline works and gives reassurance about the side effects that you might experience, especially in the early stages.

The main aims in managing chronic pain are to relieve the pain and just as importantly to improve your quality of life and get you doing more. There are four approaches to pain management: 1) physical therapy (physiotherapy, acupuncture, TENS (transcutaneous electrical nerve stimulation) etc. 2) drug therapy; 3) regional analgesia (injection of drugs around nerves or other tissues); and 4) psychological therapies (techniques which improve coping of pain).

Two types of pain
Doctors describe pain as either nociceptive, neuropathic, or a combination of the two. It is important to distinguish between the two types of pain, as they need different medicines. Nociceptive pain is pain that starts off as a response to tissue damage or a painful stimulus like a hot surface. Examples include mechanical low back pain and degenerative or inflammatory joint pain and so it is easy to understand why nociceptive pain is the most common form of chronic pain. Although these pains may begin as purely nociceptive, over time there may be changes within the nervous system that may result in neuropathic pain. Neuropathic pain may also be the result of nerve damage that makes the nerve overactive. Therefore the drugs used for neuropathic pain are aimed at stabilisation or “calming” of the abnormal nerves. Perhaps it should be no surprise that drugs used in other conditions where nervous tissue is overactive or “excited” such as epilepsy or depression have turned out to be useful medicines for chronic pain where the nerves have become overactive.

Drug therapy
Conventional painkillers such as codeine and brufen are used for nociceptive pain. They are often not effective for neuropathic pain. Most of the drugs used for neuropathic pain are not just used for pain relief (analgesia). For instance, amitriptyline is an anti-depressant drug but is now probably used more commonly for pain than for its original use. This is the same situation for some anti-convulsant drugs, which are used more frequently for neuropathic pain than epilepsy.

Change your lifestyle!
Always remember that the medicine alone will not be enough. While drug therapy can play a major role in the management of pain, changing your lifestyle (such as building up your fitness and getting more exercise) as well as learning to manage and cope with your pain better, are also vital to the successful outcome.

General principles of drug therapy
Your doctor will start you off at a low dose of your medicine and this is increased up to a suitable dosage and duration until you obtain noticeable pain relief (or experience severe side effects). This procedure of increasing the dose step by step while monitoring the effect is called “titrating the dose”. If there is no relief the drug will be stopped. Your doctor is likely to gradually wean you off the medication over one to two weeks, to avoid potential side effects from sudden withdrawal. If you get partial, but inadequate pain relief, a second different drug can be prescribed in addition.

Once you are on the right dose and drug combination for you then you can continue on the medication indefinitely. You and your doctor may decide that you should wean off the medicines gradually every six months or so to ensure they are still necessary for you.

Most doctors agree that medication for chronic pain should be taken “round the clock” rather than “as required”. It is easier to keep pain at bay rather than trying to control it after it is allowed to resurface.

Antidepressants
The tricyclic antidepressants, such as amitriptyline, are the “gold standard” for neuropathic pain as they are the most effective and best-known drugs for this condition. They can also be useful for chronic nociceptive pain, especially if there is a neuropathic component to it. They appear to work in the nervous system by reducing the nerve cell’s ability to re-absorb chemicals such as serotonin and noradrenaline.These chemicals are called neural transmitters. If they are not reabsorbed they accumulate outside the nerve cell and the result is suppression of pain messages in the spinal cord.

All in the mind?
The way antidepressants give pain relief is completely separate from the anti-depressant effect. The dose required for treating depression is much higher (often over 150 milligrams (mg) a day) than the doses used for pain relief. Also, there are many different antidepressant drugs available that are effective for treating depression, but only a small number are also effective pain killers.
It is important for you the patient to be given a full explanation of the rationale for antidepressant therapy. It is not that the doctor believes your pain is due to depression. So do not think you are not being taken seriously and that the pain is “all in the mind”.

Of course, depression can occur with chronic pain, but it is usually an understandable reaction to the pain and improves as the chronic pain improves. However if severe it too may require treatment with an antidepressant drug.

Starting amitriptyline
One in three people will get greater than 50% pain relief with amitriptyline, which is regarded as an excellent result for chronic pain conditions. It is started at a low dose (10 or 25 mg a day) and gradually increased in 10 or 25 mg increments each week up towards 100 mg if any side effects are tolerable. The tablets are small and difficult to cut in half, and will often produce numbness of the tongue due to a local anaesthetic effect, but it is available as a syrup. It is better to use the syrup if small increases of dose are required during the titration (dose build up) phase.

Keep taking it!
You may notice pain relief as soon as two weeks after starting, but often amitriptyline requires to be taken for six to eight weeks at the best dose level before one can say the drug has been given a fair trial. Many people stop taking the medicine because they experience side effects early on but do not feel any benefit. However, if you can persevere, you will often get tolerant to most of the side effects after a few days to weeks and you may then start noticing the benefits of the medicine.

Although there are number of side effects associated with amitriptyline most of them are extremely uncommon. The most common ones, experienced by only 5-15% of people, include dizziness, drowsiness, dry mouth, nausea and constipation. These side effects are generally harmless and provided you do not exceed the dose will not cause any damage. Most people find they adapt to these and eventually they go away. Amitriptyline is not addictive but if discontinued, should be withdrawn slowly over two to three weeks in order to avoid withdrawal symptoms of headache and malaise.

Not for everyone
Your doctor will not prescribe this drug for you if you have had an allergic reaction to amitriptyline or related drugs; a recent heart attack; or recent administration of drugs that can interact with amitriptyline.

When should I take it?
Amitriptyline is long acting, so only needs to be taken once a day. As one of the most common side effects is drowsiness, it is best to take it a couple of hours before bedtime. This effect can be particularly useful if you suffer lack of sleep from your pain. Sometimes there is a “morning after” type of hangover feeling, but this usually wears off with time. Occasionally amitriptyline can cause insomnia; if this happens it is better to take it in the morning.

Worth trying
If side effects are a problem, there are other similar drugs (for example nortriptyline, and imipramine) that are worth trying.
Many people stay on amitriptyline for years and say that it has transformed their lives. When dealing with pain, it is worth giving drug therapy a chance and working with your doctor to try different approaches so that you find the particular approach that is right for you, which brings you the benefits of pain relief , allows you to do more and gives you the quality of life that you and your doctor both want.

Dr Mick Serpell is Consultant and Senior Lecturer in Anaesthesia and Pain Management at University Department of Anaesthesia, Gartnavel General Hospital, Glasgow.

A series of withdrawals of major drugs have caused widespread concern for patients and pharmaceutical companies alike.

Merck, the US manufacturer of Cox-2 inhibitor Vioxx, withdrew the drug after they noticed an increase in nonfatal heart attacks amongst patients undergoing a 3-year international trial on the drug. The trial was testing a promising new indication for Vioxx (also known as rofecoxib) in the prevention of the recurrence of colon polyps in patients that have been treated for these tumours. Warnings to patients already predisposed to heart attacks and strokes have been contained in the patient information for Vioxx since its release over 5 years ago, but the results from the recent trial were such that the company decided to voluntarily withdraw the drug. However, there are questions about how much the company and the regulatory authorities knew or should have known about the heart risks and whether the drug should have been withdrawn earlier, especially as there are safer alternatives. Indeed, Pfizer, another US drug firm, were quick to promote their Cox-2 inhibitor, Celebrex (celecoxib) as a safe alternative, in the aftermath of Merck’s withdrawal of Vioxx, but it too is under investigation for possible heart problems and sales are falling.

The main losers in all of this are arthritis pain sufferers who have lost medicines that improved their life and are now left wondering if the very pills that brought that relief have harmed them. Mo Atachia of Arthritis Care, quoted on the BBC website, said that “It’s essential that the European safety regulators deliver a swift a verdict as possible on the whole class of Cox-2 treatments”.

How can this happen?

So how can our medicines cause such serious side effects when they are supposed to be tested for safety? The problem is that it is always easier to prove that a drug is unsafe than to prove the opposite. Let’s say a potential new pain treatment causes heart disease in 10% of patients at normal doses. That would most likely show up in early animal tests and no human patient would ever be given the drug – it’s been proven unsafe. What about if the risk is 1% or 0.1%? This might still be an unacceptable risk, but because it is rare there is a good chance that safety tests in animals will not pick it up and even widespread patient trials could miss it.

Only when the number of patients receiving the drug is up in the hundreds of thousands might some rare, but unacceptable risk emerge. “Sometimes then you may pick up side effects that we hadn’t been able to see during clinical trials” (European drug regulator quoted on the BBC website). The US Food and Drug Administration (FDA) looked at the risk of heart attack for Vioxx. 1.4 million Californians who had used painkillers were analysed. In round figures 1 million patients used ibuprofen, 400 000 used naproxen, 40 000 used celecoxib and 27 000 used Vioxx. Amongst the 1.4 million patients the total number with coronary heart disease was 8100 (0.6%), but when the incidence of coronary heart disease was compared with individual drugs they found a 1.6x higher risk, i.e. 1% in patients using Vioxx.

So if you are a doctor in California and you have 1000 patients on painkillers other than Vioxx, you might find that 6 of them have coronary heart disease. And if you have 1000 patients on Vioxx you might find that 10 have heart disease. That’s the problem. How do you decide if such a small increase is chance or genuinely due to the drug? Are some of the other painkillers protecting against heart disease (like aspirin does) or are some of the ibuprofen users taking it for sprains caused by jogging – these people would be unlikely to get heart disease compared with some one with rheumatoid arthritis. Merck’s spokesman points out that heart disease is multifactorial and must be assessed case by case. Only as pieces of evidence like that accumulate with time can some sort of certainty emerge which enables a balance to be struck between putting patients at unacceptable risk of dangerous side effects and depriving patients of beneficial life enhancing medicines. It’s never going to be easy and the only certainty is that mistakes can be made in both directions.

Co-proxamol

In another development, the UK drug authority (the Medicines and Healthcare Regulatory Agency) has ordered the withdrawal of co-proxamol following a report from the Committee on Safety of Medicines (CSM). The reason is that four hundred people commit suicide every year using co-proxamol. Patient groups are really finding it hard to understand why this should lead to their being deprived of an effective treatment. The chairman of the CSM, Professor Gordon Duff, said that there was no need for panic or concern. Arthritis Research Campaign are concerned: It’s incredibly bad news, they said.

The problem is not just suicide. There are a number of accidental deaths with co-proximal especially when used with alcohol and there is no denying its toxicity. The problem for regulators is that while there is “great brand loyalty” according to one GP writing to the BBC website, there is little objective evidence that co-proximal is any better than other pain killers such as paracetamol (itself not exactly the safest substance people pop into their mouths). Nonetheless pain is a symptom, an internal perception, and if a patient states that Drug A gives them better relief than Drug B it is hard to do anything other than believe them.

Individual patients are adding their own stories to web sites and letters pages all saying the same – that for them co-proximal gives relief like no other medicine. The rights and wrongs of this are hard to determine, but it all adds up to very bad news for pain sufferers as medicines are withdrawn and symptoms return.

But What About Opioids?

The opioids have suffered a bad press because of addiction but as the cox-2 saga developed perhaps its time to look again at older drugs such as morphine. Addiction is in fact over stated as a risk and few people suffer more than constipation, yet their efficacy as painkillers is very high. Will governments overcome their fears on recreational use and make these highly safe and efficacious drugs more widely available? People wanting more information should start with the British Pain Society’s leaflet “Opioid Medicines for Persistent Pain” (see below).

And Cannabis??

If opioids are finding it hard to overcome political prejudice then multiply it several times for cannabis. At the moment many people whose only crime is to be incurably ill are risking a criminal prosecution for acquiring and using cannabis. All eyes are on Health Canada, that country’s regulator of drugs who will shortly decide whether to licence an oral spray of cannabis (Sativex). Spain, too, is about to start a trial. Marijuana affects behaviour by imitating the effects of natural brain chemicals called endocannabinoids. These natural chemicals help in the regulation of pain, nausea, anxiety and hunger. Hopefully drugs based on the endocannabinoids will give better pain relief than actual cannabis and will not meet the political resistance that use of the real weed does

OK, There’s Always Complementary Medicine

Imperfect though the safety evaluation of drugs might be, at least there is a system. In contrast many “natural” or “alternatives” are subject to no testing whatsoever. In a recent landmark ruling two doctors working outside the NHS were convicted of serious professional misconduct for prescribing complementary therapies to patients with breast cancer. None of the prescribed treatments had any evidence that they were effective and the information handed out to patients was not evidence-based. The judgement said that “Providing information about a treatment for which there was no scientific evidence was irresponsible and not in the best interests of patients”. This does not mean that complementary medicine is not effective, but that any treatment, whether herbal or produced by a major drug company must have evidence behind it that it works and is safe and is the best treatment for that particular patient