Gout
What Is Gout?
Gout.
Gout
is a type of arthritis (inflammation of the joints) that mostly affects men
age 40 and older. It is caused by chronic hyperuricemia--a
long-lasting, abnormally high concentration of uric acid in the blood. Purines,
nitrogen-containing compounds, are the chemical sources of uric acid and can
be divided into two types, endogenous and exogenous. Endogenous purines are
synthesized within the nuclei of cells in the human body itself, whereas the
exogenous purines are obtained from foods. Uric acid is the end product of
purine metabolism and is mostly produced in the liver. From there it enters
the bloodstream. Most of uric acid eventually passes through the kidneys and
is excreted in the urine; the rest is disposed of in the intestines, where it
is processed and oxidized by bacteria.
Normally these processes keep the
concentration of uric acid in the blood plasma (the liquid part of the blood)
below 7 milligrams per deciliter (7 mg/dL). Under certain circumstances,
however, the body produces too much uric acid or excretes too little,
resulting in levels above 7 mg/dL--the point at which hyperuricemia develops.
In the bloodstream, uric acid exists predominantly as a dissolved salt called
monosodium urate (MSU). At 37 degrees C (normal body temperature) and at a
uric acid concentration approaching 7 mg/dL, the blood plasma becomes
supersaturated, and needlelike crystals of MSU form. Crystallization is
governed by other factors as well. In joints, such as the knee and ankle,
temperatures are cooler (29 degrees C to 32 degrees C), and MSU crystals are
able to form at even lower uric acid concentrations, which explains why gout
favors these joints. In time, MSU crystals can provoke an inflammatory
response that produces the symptoms characteristic of gout.
In respect to gout, humans are less fortunate
than many animals, which never suffer from gout
because they possess uricase, an enzyme that converts uric acid to allantoin,
a substance much more easily excreted by the kidneys.
What Causes Gout?
Gout
is classified as either primary (the most common type) or secondary, depending
on the cause of the associated hyperuricemia. In both types of gout,
between 70% to 95% of hyperuricemia cases are the result of underexcretion of
uric acid, rather than uric acid overproduction.
Primary Gout.
Hyperuricemia in primary gout
arises or is presumed to arise from a genetic or other inborn disorders that
cause metabolic problem resulting in overproduction of uric acid or reduced
excretion of uric acid. More than 99% of primary gout
cases, however, are idiopathic, meaning that the cause of the hyperuricemia
cannot be determined. The remaining cases are traceable to either of two rare
inherited enzyme defects that affect purine synthesis in the cells.
Secondary Gout.
In secondary gout,
hyperuricemia is caused by drug therapy or by medical conditions other than an
inborn metabolic disorder.
Medications.
Thiazide
diuretics (the "water pills" used to control hypertension) cause
hyperuricemia by decreasing uric acid excretion. The list of drugs that cause
hyperuricemia is long and includes not only diuretics but also pyrazinamide
(used to treat tuberculosis) and the immunosuppressive drug cyclosporine
(given to transplant recipients to prevent organ rejection). Low doses of
aspirin and other salicylates decrease uric acid excretion, whereas high doses
have the opposite effect.
Kidney Disorders. Renal
(meaning kidney) insufficiency is the impaired ability of the kidneys to
eliminate waste products, including uric acid, which then build up in the
blood. Gout is associated with three primary
disorders that can cause renal insufficiency: urate nephropathy; uric
acid nephropathy; and uric acid nephrolithiasis.
Urate nephropathy occurs when
monosodium urate crystals form in kidney tissue is uncommon and researchers
believe that it usually causes only minor kidney damage.
Uric acid nephropathy is a
disorder that occurs uric acid crystals from urine forming in the structures
and tubes that carry fluid from the kidney. It most often occurs during
chemotherapy for lymphoma or leukemia. It can result in kidney failure by
obstructing urine flow, but is preventable and reversible.
Uric acid nephrolithiasis occurs
when kidney stones form from uric acid. Uric acid and other kidney stones are
present in 10% to 25% of patients with primary gout--a prevalence more than
1000 times that in the general population. In secondary gout,
the reported incidence reaches 42%. Uric acid stones can also form in the
absence of gout or hyperuricemia. Not all of
the kidney stones in patients with gout are
composed of uric acid; some are composed of calcium oxalate, calcium
phosphate, or those substances combined with uric acid. Kidney stones can be
extraordinarily painful and can cause infection and kidney failure if
untreated.
Other Medical Conditions.
A
number of diseases, including leukemia, lymphoma, and psoriasis, can cause gout.
Over exposure to lead can cause gout.
Alcohol Use.
Alcohol use
increases uric acid levels in three ways: by providing an additional dietary
source of purines (the compounds from which uric acid is formed); by
intensifying the body's production of uric acid; and by interfering with the
kidneys' ability to excrete uric acid.
Purine-Rich Diet. A purine-rich
diet rarely causes hyperuricemia, although it may precipitate an attack in
some people with existing gout. [For a list of
purine-rich foods, see What Lifestyle Measures Can Help Prevent Gout?,
below.]
What Are The Symptoms Of Gout?
Gout
is often divided by experts into four symptomatic stages: asymptomatic
hyperuricemia, acute gouty arthritis,
intercritical gout, and chronic tophaceous gout.
Gout symptoms can be precipitated by stress,
infection, joint injury, weight loss, surgery, certain kinds of drug
treatment, overindulgence in alcohol or purine-rich foods, or even something
as seemingly inconsequential as a long walk that one was not sufficiently
physically fit to undertake. The tend to occur more in the spring than other
seasons. Hospitalization and drug treatment are probably the most significant
triggers, and in fact, 20% to 86% of those who have had gout
experience a recurrence when they are hospitalized.
Asymptomatic Hyperuricemia.
Asymptomatic hyperuricemia always
precedes gout and is considered the first
stage of the disorder. It can last, however, for an average of 30 years.
Hyperuricemia also does not inevitably lead to gout.
In fact, less than 20% of the hyperuricemic population develops this arthritic
disease.
Acute Gouty Arthritis.
Acute gouty
arthritis is the stage at which the first symptoms of gout
appear. Sometimes gout is heralded by brief
twinges of pain (petit attacks) in an affected joint, which can precede the
actual full-blown condition by several years.
Symptoms usually begin as a
sudden, severe, and unexpected arthritic attack affecting a single joint in
one of the lower limbs, a condition known as monoarticular gout.
The joint of the big toe is the site of about half of all first gout
attacks--a specific condition called podagra. The site is often medically
referred to as the big toe's metatarsophalangeal (MTP) joint--the point where
one of the long five bones of the foot meets the first digit of a toe.
The joints of the foot, ankle,
knee, wrist, elbow, and hand are other frequently affected sites. In such
cases the condition is known as polyarticular gout.
More than one joint is affected in 10% to 20% of first attacks. The pain
usually occurs in joints on one side of the body and it usually, although not
alway in the lower extremities. People with polyarticular gout
are more likely to have a more gradual onset of pain and a longer delay
between attacks. They also more likely to experience a low-grade fever, loss
of appetite, and a general feeling of unwellness.
The primary symptom, which
usually takes eight to 12 hours to develop, is severe, sometimes crushing pain
at and around the joint. In many cases the attack occurs late at night or
early in the morning and announces itself by waking the sufferer. Some
patients describe it as resembling a disoclated bone and one writer described
it as "like walking on my eyeballs". Chills and mild fever may
follow. The area can be so tender that walking and even the weight of
bedsheets can be unbearable. Swelling may extend beyond the joint, indicating
fluid build-up within. The skin over the affected area is often red, shiny,
and tense. After a few days it may start to peel. An untreated attack will
typically peak 24 to 48 hours after the initial appearance of symptoms, and
subside after five to seven days, although it can last only hours to several
weeks.
Intercritical Gout.
Intercritical gout
is the term used to describe the periods between attacks. The first attack is
usually followed by a complete remission of symptoms, but in untreated cases
most people can expect a recurrence. One study found that 62% of subjects
experienced at least one further attack within a year. At the end of two years
78% and after 10 years 93% of patients experienced a recurrence of gout.
Chronic Tophaceous Gout.
When gout
remains untreated, the intercritical periods typically become shorter and
shorter, and the attacks--although sometimes less intense--can last longer. Gout
may also eventually affect several joints, including those that may have been
free of symptoms at the first appearance of the disorder. In rare cases, the
shoulders, hips, or spine are affected. Over the long term--about 10 to 20
years--in untreated gout the intercritical
periods dwindle until gout becomes a chronic
disorder characterized by constant low-grade pain and mild or acute
inflammation in several joints. Persistent gout,
moreover, can destroy cartilage and bone, causing irreversible joint
deformities and loss of motion.
Tophi. After several
years, persistent gout can produce tophi,
which are solid deposits of MSU crystals that form in the joints and elsewhere
in the body (hence the term chronic tophaceous gout).
Without anti-hyperuricemia treatment, tophi develop on average about 10 years
after the onset of the disease although their first appearance can range from
three to 42 years. Bones, cartilage, tendons, soft tissue, and membranes
containing synovial fluid (the lubricating fluid surrounding joints) can all
harbor tophi. Common locations include the helix of the outer ear (the curved
ridge along the edge of the ear), the fingers, hands, forearms, knees, and
feet, and the olecranon bursa (a sac at the elbow joint filled with synovial
fluid). In some cases, tophi break through the skin and appear as white or
yellowish-white chalky nodules. (They have been described as looking like
"crabs eyes.") Although tophi themselves are generally painless,
they often cause pain and stiffness in an affected joint and can erode
cartilage and bone, ultimately destroying the joint. Large tophi under the
skin of the hands and feet can give rise to extreme deformities. In rare
cases, they can settle in regions around the heart and spine. Today, drug
therapy has reduced the prevalence of chronic tophaceous gout
to as little as 3%, although certain groups, such as transplant patients
receiving cyclosporine, still face a high risk of developing tophi.
How Serious Is Gout?
In the past, gout
often developed into a painful and disabling chronic disorder. Tophi could
destroy bone and cartilage in the joints, similar to rheumatoid arthritis. But
now, after several decades of research into the causes of gout
and the development of drugs for controlling hyperuricemia, gout
rarely poses a long-term threat to health if properly treated. Still, it
remains a source of short-term pain and incapacity for thousands of Americans.
Although gout
itself is not life-threatening, it is often associated with serious diseases.
Diabetes and obesity are very common in gout
patients as well as high blood pressure and kidney disease. Kidney disease, in
fact, is more common in gout patients than in
people with diabetes. (Gout, however, is more
likely to be caused by kidney problems than is hyperuricemia the cause of
kidney abnormalities.) Kidney stones are also common in people with gout
and occur in between 10% and 40% of patients. Usually the stones are composed
of uric acid but they may also be formed from other materials.
Who Gets Gout?
Prevalence.
Gout
is one of the most common types of arthritis. In the United States there were
an estimated 2.2 million cases of self-reported gout
in 1986, and a 1991 publication noted that Americans lost an estimated 37
million working days a year to gout. It is
estimated that approximately 15 of every 1,000 American males between 35 and
45 years of age have gout and some experts
believe that one in 100 men may be at risk for it. It is very uncommon in less
developed countries and in 1952 it was said to be unkown in China, Japan, the
tropics, and rare among African Americans. The prevalence of gout
not only in America but in other developed countries has, however, been rising
in recent decades, possibly because of dietary and lifestyle changes, greater
use of medications that cause hyperuricemia, and aging populations.
Gender and Age Differences
Gout
typically strikes only after 20 to 40 years of persistent hyperuricemia and
men tend to have higher uric acid levels than women. For these reasons, men
over 40 years old account for about 90% of the population affected by gout.
Among children, the levels of uric acid are the same for both genders (an
average of 3 to 4 milligrams (mg) of uric acid per deciliter (dL) of plasma.
Male levels rise substantially at puberty, with the result that the level
exceeds 7 mg/dL (considered to indicate hyperuricemia and an increased risk
for gout) in about 5% to 8% of American men.
For many men, hyperuricemia begins in puberty and may last a lifetime. Less
than 5% of patients with gout are female. The
female hormone estrogen appears to facilitates uric acid excretion by the
kidneys (the body's chief mechanism for disposing of uric acid), so levels in
women remain essentially stable until menopause, after which they approach
male levels. Premenopausal women are thus much less likely than men of the
same age to be hyperuricemic, and whereas men usually experience their first
attack of gout between the ages of 30 and 50
years old, women are more likely to experience gout
between the ages of 50 and 70. Rare inherited genetic disorders that cause
hyperuricemia can result in gout in children.
Family History.
A fairly substantial proportion
of patients with gout (10% to 20%) have a
family history of gout, but it is not known if
genetics, environmental factors, or both play roles in this association.
Other Risk Factors.
Risk factors are attributes or
activities associated with a greater-than-normal likelihood of developing a
particular disorder (as in the case of obesity and heart disease, or smoking
and lung cancer). Sometimes a causal connection between the attribute or
activity and the disorder can be established, but at other times there is
simply a statistical correlation. The risk factors for gout,
of which there are several, are identical to those for hyperuricemia.
Obesity. Researchers
report a clear link between body weight and uric acid levels and have also
discovered that obesity is an especially important risk factor in men.
Hypertension. Hypertension
(high blood pressure) is found in 25% to 50% of patients with gout,
but whether it causes hyperuricemia is uncertain.
Alcohol use. Alcohol use is
associated with gout and in one study, it was
the only notable risk factor for women with gout.
How Is Gout Diagnosed?
Standard diagnostic tools for gout
may include a medical history and physical examination, a blood test for
hyperuricemia, and urine sample. For a definitive diagnosis of gout,
a sample of synovial fluid from the affected joint is required. X-rays can
provide helpful information in some cases.
Ruling Out Other Disorders.
As part of the diagnostic
process other disorders that resemble gout
symptoms or cause hyperuricemia should be ruled out. Some experts believe both
gout and pseudogout are underdiagnosed in
hospital patients resulting in incorrect therapy--for example antibiotics for
cellulitis, a serious infection that has symptoms similar to those of gout.
Pseudogout. Pseudogout
is a condition most likely to be confused with gout.
It is caused by deposits of calcium pyrophosphate dihydrate crystals in and
around the joints. Though pseudogout resembles gout
in some ways, the first attack typically strikes the knee rather than the
joint of the big toe, and at least two-thirds of cases affects more than one
joint. The symptoms of pseudogout also appear more slowly than those of gout,
taking days rather than hours to develop.
Other Causes of Arthritic
Pain. The symptoms of gout can resemble
those of many other disorders, including acute rheumatic fever, rheumatoid
arthritis, traumatic arthritis, osteoarthritis, serious skin infections,
hallux rigidus (painful stiffness in the first joint of the big toe), and
Reiter's syndrome (a disorder characterized by arthritis, urethritis, and
conjunctivitis). Many of these disorders can be present at the same time as gout.
Other Causes of Hyperuricemia.
Binge drinking, fasting, lead toxicity, leukemia, certain uncommon anemias,
multiple myeloma, and lymphomas are also uncommon causes of high uric acid
concentrations.
DISEASES WHICH CAUSE FEVER WITH
JOINT AND MUSCLE PAIN
Osteoarthritis.
Infectious Arthritis.
Lyme
disease, septic arthritis, bacterial endocarditis, mycobacterial and fungal
arthritis, viral arthritis
Postinfectious or Reactive
Arthritis.
Enteric infection, Reiter's syndrome, rheumatic fever,
inflammatory bowel disease
Rheumatoid Arthritis
.
(including Still's Disease, also called Juvenile Rheumatoid Arthritis)
Systemic Rheumatic Illness.
Systemic
vasculitis, systemic lupus erythematosus, scleroderma
Fibromyalgia.
Other Diseases
. Chronic
fatigue syndrome, hepatitis C, familial Mediterranean fever, cancers, AIDS,
leukemia, Whipple's disease, dermatomyositis, Behcet's disease,
Henoch-Schonlein purpura, Kawasaki's disease, erythema nodosum, erythema
multiforme, pyoderma gangrenosum, pustular psoriasis
Medical History and Physical Examination.
Determining which joints are
affected in a patient suspected of having gout
is an obvious first step in any diagnosis. A physician is more likely to
suspect gout as the cause of an acute attach
of arthritis if it first appears in the first joint of the big toe than it if
arthritis attacked, for example, a shoulder or hip. The examiner also needs to
determine whether the onset of pain and swelling was rapid, for symptoms that
require days or weeks rather than hours to develop probably indicate a
disorder other than gout. Another possible
indicator of gout is previous damage to an
affected joint, because gout often arises in
injured joints.
Blood Test.
A blood test is usually given,
although some experts argue that it isn't necessary, given what is now known
about the variability of uric acid levels in people with gout.
Uric acid levels in the blood during an attack of gout
do not necessarily mirror levels before the attack, and in fact can lie within
or below the normal range. Even if hyperuricemia is present, it is very common
in the population and does not necessarily indicate the presence of gout.
A low level of uric acid in the blood however, makes a diagnosis of gout
much less probable, and a very high level increases the likelihood of gout.
24-Hour Urine Sample.
It is sometimes helpful to gauge
the amount of uric acid excreted by the patient over the course of 24 hours,
particularly if the patient is young and has pronounced hyperuricemia that
might be related to a metabolic disorder. If the amount exceeds a particular
value, further tests for an enzyme defect or other identifiable cause of gout
arising from uric acid overproduction are justified. Greater-than-normal
amounts of uric acid in the urine also indicate that the patient faces a
greater risk of developing uric acid kidney stones, and can guide the
physician in his or her choice of drug therapy for chronic gout.
The urine is collected during an intercritical period, after the patient has
been placed on a purine-reduced diet. The patient is also asked to temporarily
stop using alcohol and any medications that can interfere with the test. On
the first day of the test, the urine passed by the patient on waking up in the
morning is discarded, but for the next 24 hours the patient collects all of
his or her urine in a special container. The test concludes the next morning
with the patient urinating into the container right after waking up. The
container is then delivered to the patient's physician or sent directly to the
laboratory.
Examination of Synovial Fluid.
The synovial fluid is the
lubricating liquid that fills the synovium, the membrane that surrounds a
joint and creates a protective sac. In addition to cushioning joints, this
fluid supplies nutrients and oxygen to cartilage, the slippery tissue that
coats the ends of bones. The procedure for taking a sample of synovial fluid
from an affected joint is called aspiration. A needle attached to a syringe is
inserted into the joint and suction is used to draw the fluid into the
syringe. Local anesthesia is avoided because it can reduce the effectiveness
of aspiration, but normally the procedure is only mildly uncomfortable.
Following the procedure there can be some minor discomfort in the area where
the needle was inserted, but it usually dissipates quickly. Aspiration can
cause infection, though this occurs in less than 0.1% of patients. After the
sample is taken, it is sent to a laboratory, where a microscope is used to
look for monosodium urate (MSU) crystals, which can be detected with polarized
light. The laboratory can also test the sample for infection (always a
possibility in cases of gout). Another benefit
of aspiration is that it sometimes eases a patient's symptoms by reducing
swelling and pressure on the tissue surrounding the joint.
X-Rays.
For the most part, x-rays do not
reveal any abnormalities during the early stages of gout,
and their usefulness where gout is concerned
lies in assessing the progress of the disorder in its chronic phase and in
identifying other health problems whose symptoms may resemble those of gout.
Tophi can be seen on x-rays before they become apparent on physical
examination.
Trial of Colchicine.
Until recently a standard
diagnostic test was administering a trial of the traditional antigout drug
colchicine. Improvement in the patient's condition after taking the drug is an
indication of gout. There are limitations,
however, to this approach. Colchicine often has distressing side effects,
including nausea, vomiting, diarrhea, and abdominal cramps when taken orally.
In any event, its attractiveness as a diagnostic tool is limited because it
can also relieve symptoms in other arthritic conditions, including pseudogout.
How Is Gout Treated?
General Guidelines.
Acute attacks of gout
and long-term treatment of gout and its
associated hyperuricemia require different approaches. All phases are mainly
treated mainly with drugs. There are also specific treatment regimes for cause
common causes of gout, including uric acid
nephropathy and uric acid nephrolithiasis.
Treatments for Asymptomatic
Hyperuricemia.Because asymptomatic hyperuricemia usually does not lead to gout
or other health problems, and would have to be treated with drugs that present
certain risks and can be expensive, treatment to prevent a first attack of gout
in hyperuricemic patients is considered inadvisable. In unusual circumstances,
for example when very high uric acid levels create a risk of kidney toxicity,
treatment may be justified.
Treatment of Acute Gouty
Arthritis.
Drug treatments for acute attacks of gout
are aimed at relieving pain and reducing inflammation. Powerful forms of
nonsteroidal anti-inflammatory drugs (NSAIDs are the drugs of choice for an
acute attack. Colchicine or corticosteroids may also be used. Rest, applying
cold, and protecting the affected joint with a splint can also promote
recovery. Acute attacks respond best to immediate treatment. After the first
attack, some physicians advise their patients to keep a supply of medications
for an acute attack on hand so that self-medication can begin at the first
sign of symptoms.
Treatment for Intercritical
Period and Tophaceous Gout.
During the
period between gout attacks, patients are
advised to avoid foods high in purines and to maintain a healthy weight.
Patients should also avoid alcohol and reduce any stress. Many patients do not
require medications. Usually preventive drug therapy is used only if there are
two or three attacks that occur within a year. Some physicians prescribe
low-dose NSAIDs or colchicine to prevent recurrent attacks. Increasing the
dose when a patient believes an attack is pending can often abort it. These
are simply anti-inflammatory drugs, however, and have no effect on
hyperuricemia.
The goals of antihyperuricemic
therapy are to reduce uric acid levels to normal, decrease the frequency of
attacks, and to dissolve monosodium urate (MSU) crystals and tophi.
Allopurinol and drugs known as uricosurics, which include probenecid and
sulfinpyrazone, are available for these purposes and are all very effective.
Which drug to prescribe depends on individual conditions [ see Specific
Drugs for Long-Term Treatment, below]. When and if to prescribe them at
all, however, is not entirely clear. Some physicians do not prescribe them if
hyperuricemia is mild and not until a patient has had two attacks. Others
prescribe them immediately after a single attack. It should be noted that any
of these drugs can actually precipitate acute gout
symptoms and so should not used until symptoms have subsided, and then the
patient should start with small doses that gradually increase. Colchicine or
an immediate-acting NSAID, such as naprosyn, should be given during the
initial months of therapy to prevent symptoms attacks. Most of the time,
antihyperuricemic therapy means taking a drug routinely throughout life, which
many people find difficult to adhere to. In rare cases, surgery is used to
treat the effects of chronic gout.
Specific Drugs Used for Acute Attacks.
Nonsteroidal Anti-Inflammatory
Drugs (NSAIDs). Nonsteroidal anti-inflammatory drugs (NSAIDs block
prostaglandins, the substances that dilate blood vessels and cause
inflammation and pain. They are taken orally at their highest safe dosage as
long as symptoms persist and for three or four days after. There are dozens of
NSAIDs. Indomethacin (Indocin) is the usual choice for gout;
ibuprofen, naproxen, sulindac, or others are good alternatives particularly
for elderly patients who might experience confusion or bizarre sensations with
indomethacin [ see below]. The first dose of indomethacin usually
begins to act against the pain and inflammation of gout
within 24 hours, and often much sooner.
Taking NSAIDs with food can
reduce discomfort, although it may slow down the pain-relieving effect. All
NSAIDs are capable of damaging the mucous layer and causing ulcers and
gastrointestinal (GI) bleeding when taken for long periods. They also appear
to delay the emptying of the stomach, which may interfere the actions of other
drugs. The elderly are at special risk for GI bleeding. Younger nonsmoking
adults adapt better to NSAIDs. Bleeding and ulcers can occur at any time, with
or without symptoms. The risk for bleeding is continuous as long as a patient
is on these drugs and may even persist for about a year after taking them. No
NSAIDs should be used for long-term pain relief except under a physician's
direction. One study ranked the sixteen most commonly used NSAIDs according to
GI toxicity. Those at lowest risk were nabumetone (Relafen), etodolac
(Lodine), salsalate, and sulindac (Clinoril). At medium risk were aspirin,
diclofenac (Voltaren), ibuprofen (Motrin, Advil, Nuprin, Rufen), naproxen
(Aleve, Naprosyn, Naprelan, Anaprox), and tolmetin (Tolectin). Drugs within
this group, however, vary in risk. Studies show, for example, that short-term
use of naproxen is twice as likely as ibuprofen to be associated with
hospitalization from GI bleeding. Although ketoprofen (Actron, Orudis,
Oruvail) was considered medium risk, one study reported that even one week of
taking the drug at low doses causes significant GI injury. The highest risk
for GI bleeding were from flurbiprofen (Ansaid), piroxicam (Feldene),
fenoprofen, indomethacin (Indocin), meclofenamate (Meclomen), and oxaprozin
(Daypro). Others not compared in this analysis were diflunisal (Dolobid), and
ketorolac (Toradol).
A gel containing ibuprofen can be
applied to sore joints and may have less risk for gastrointestinal side
effects. New studies suggest that taking the drug omeprazole (Prilosec), known
as a proton-pump inhibitor, along with NSAIDs can both heal and help prevent
NSAID-related ulcers. Misoprostol (Cytotec) is a drug that is also commonly
used to prevent NSAID-induced ulcers. A drug (Arthrotec) that combines
diclofenac and misoprostol is proving had 65% to 80% fewer ulcers than those
patients who took NSAIDs alone. Unfortunately misoprostol has its own side
effects that include diarrhea, cramps, and gas. Common antacids, or H2
blockers, such as ranitidine (Zantac), cimetidine (Tagamet), famotidine
(Pepcid), and nizatidine (Axid), reduce symptoms caused by gas but do not keep
NSAIDs from causing ulcers. In fact, such drugs may pose a danger by masking
symptoms of developing ulcers.
Other side effects of NSAIDs
include dizziness, ringing in the ear, headache, and skin rash. Depression has
also been noted. Kidney damage has been reported in people taking NSAIDs,
which resolves when the drugs are withdrawn. (Aspirin has little or no risk
for this side effect.) NSAIDs may also increase blood pressure, particularly
in those on medications to reduce hypertension. Piroxicam (Feldene), naproxen
(Aleve), and indomethacin (Indocin) appear to pose the greatest risks for high
blood pressure. Sulindac (Clinoril has the smallest effect. People with
hypertension, severe vascular disease, kidney, or liver problems, and those
taking diuretics must be closely monitored if they need to take NSAIDs. Any
sudden weight gain or swelling should be reported to a physician. Because
NSAIDs reduce the clotting of the blood, anyone undergoing surgery should stop
taking the medication a week before the operation. Diabetics taking oral
hypoglycemics may need to adjust the dosage if they also need to take NSAIDs
because of possible harmful interactions between the drugs. Alcohol abuse may
increase the risks for bleeding.
Colchicine. Colchicine, a
derivative of the autumn crocus (also called the meadow saffron), has been
used against gout for centuries. It is highly
effective though no longer the first drug of choice because of its frequent
and unpleasant side effects. Although colchicine usually eliminates the pain
of an acute attack within 48 hours, it is unsuitable for many patients because
of nausea, vomiting, diarrhea, or abdominal cramps after taking the drug.
Colchicine is usually taken orally, but can be administered intravenously to
patients who are unable to take oral medications because of severe
gastrointestinal side effect or if oral administration is not possible. The
intravenous route is riskier, however, and poses an incresaed risk for harmful
effects in the kidney, liver, central nervous system, and bone marrow. The
oral regimen requires doses every hour until the patient either improves or
side effects develop; improvement should be evident by the tenth dose.
Cimetidine (Tagamet) and the antibiotic erythromycin can intensify the side
effects of colchicine, so patients taking those drugs need to be monitored and
their use of colchicine halted if they begin to suffer gastrointestinal
difficulties. Colchicine is not appropriate for patients with kidney, liver,
or bone marrow disorders.
Corticosteroids. The
corticosteroids, known commonly as steroids, are used only when patients
cannot tolerate other anti-inflammatory drugs or they are ineffective. They
include triamcinolone (administered by injection) and prednisone (taken
orally). Corticotropin (ACTH), a drug that converts to a steroid, is another
option. Oral doses are usually given for seven to 10 days. A single injection
is usually sufficient. If only one joint is affected, an injection may be
administered directly to the site. Corticosteroids are sometimes followed by a
rebound attack of gout after treatment is
completed. To prevent this colchicine is given two or three times daily with
the steroid and for several days after discontinuing it. They should only be
administered for short periods and not used for long-term treatment.
Specific Drugs for Long-Term Treatment.
Long-term treatment of
hyperuricemia is recommended for tophi prevention and when the patient has
suffered several acute attacks of gout over a
number of years, when the attacks are unusually severe or affect more than one
joint, or when hyperuricemia is caused by an identifiable inborn metabolic
deficiency.
Allopurinol. Allopurinol
(Lopurin, Zyloprim) blocks uric acid production and is the drug most often
used in long-term treatment for older patients and those with high levels of
excreted uric acid (over 800 mg during a 14-hour period). It is also
considered the drug of choice for patients with impaired kidney function, a
history of kidney stones, and for tophaceous gout.
Allopurinol is taken orally only once a day in doses of 100 mg to 600 mg,
depending on the patient's response to treatment. The drug's side effects,
experienced by 3% to 5% of patients, include skin rashes, leukopenia (a
reduction in the number of white blood cells), thrombocytopenia (a reduction
in the number of platelets), diarrhea, headache, and fever. When they are
first used, allopurinol and the uricosurics can trigger further attacks of gout,
and thus during the first months (or longer) of antihyperuricemic therapy the
patient is also given an NSAID or colchicine to forestall that possibility.
Some patients experience an allergic reaction to allopurinol, which can be
fatal. However, allergic patients may be able to build up their tolerance for
the drug by undergoing a desensitization process. It may also increase the
risk for cataracts.
Uricosuric Drugs.
Probenecid (Benemid, Parbenem, Probalan) and sulfinpyrazone (Anturane) are
uricosurics, which are drugs that prevent the kidney from reabsorbing uric
acid and so increase the amount excreted in the urine. Uricosuric drugs are
usually the choice for patients under 60 years old who have normal diets and
kidney function and have no risk of kidney stones. Uricosuric drug candidates
should also produce no more than 700 to 800 mg of uric acid in urine over a
24-hour period. These drugs may actually intensify gout
symptom if they are not started until acute attacks have stopped. The initial
doses should be low and then gradually build up. Adding low-dose colchicine or
an NSAID may help prevent gout attacks.
Although allopurinol's side effects tend to be substantially more severe than
with the uricosurics, many prefer allopurinol because it is only taken once a
day. Probenecid is taken twice to three times a day and sulfinpyrazone begins
at twice a day and increases to three or four times daily. The possible side
effects of these two drugs include skin rashes, gastrointestinal problems,
anemia, and kidney stone formation. Sufficient fluid intake is important to
help reduce acidity and so prevent uric acid kidney stones. To also reduce the
urine acidity as quickly as possible, patients may also be given sodium
bicarbonate supplemented by acetazolamide. NSAIDs, particularly aspirin, as
well as other salicylate drugs, interfere with these drugs and reduce
effectiveness, so they should be avoided; patients who require minor pain
relief should take acetaminophen (Tylenol and others). Uricosurics also
interact with many other drugs, and a patient should be sure to inform the
physician of any medications they are taking. A uricosuric combined with
allopurinol is occasionally effective in cases where using just one drug is
not. Probenecid combined with colchicine is more effective than probenecid
alone, but patients respond differently to this regimen depending on the
dosage balance, so it needs to be carefully individualized.
Colchicine and NSAIDs. Low
doses of NSAIDs or colchicine are used to prevent gout
attacks in patients who are starting anti-hyperuricemic therapies. For
patients who cannot take either allopurinol or a uricosuric, low daily doses
of oral colchicine provide a possible alternative treatment for hyperuricemia,
though not among patients with renal insufficiency or liver disease.
Surgery.
Surgery is sometimes used to
remove large tophi that are draining, infected, or interfering with the
movement of joints. Several other surgical procedures are available for
relieving pain in and improving the function of affected joints. It is
sometimes necessary to replace joints.
Treatment for Pseudogout.
There is no cure for pseudogout,
but there are treatments to relieve the pain and inflammation and reduce the
frequency of attacks. NSAIDs are effective for treating inflammation and pain
from pseudogout. For acute attacks in large joints, fluid aspiration along or
with steroids may help. Intravenous colchicine is also helpful but may be
toxic. Pseudogout is a progressive disorder that can destroy joints, and joint
replacement may be required.
Treatment of Kidney Disorders That Can Cause Gout.
Uric Acid Nephropathy.
Uric acid nephropathy is common in chemotherapy patients. In such cases it is
preventable if they are adequately hydrated and given allopurinol before
chemotherapy begins. Treatment has reduced the death rate in cases of uric
acid nephropathy from about 50% to close to zero.
Uric Acid Nephrolithiasis.
Uric acid stones are dissolved by giving the patient allopurinol to reduce the
concentration of uric acid in his or her urine. The patient also takes oral
sodium bicarbonate or acetazolamide (Diamox) to alkalinize the urine. Drinking
at least 10 to 12 eight-ounce glasses of water and other nonalcoholic
beverages every day is important as well. [For more information see Kidney
Stones.]
What Lifestyle Measures Can Help Prevent Gout?
Avoid Purine-Rich Foods.
Because uric acid levels are only
minimally affected by diet, dietary therapy does not play a large role in the
prevention of gout. Still, people who have
suffered an attack of gout may benefit from
reducing their intake of purine-rich foods if they habitually eat unusually
large quantities of such foods. They include They include beer and other
alcoholic beverages, anchovies, sardines (in oil), fish roes, herring, yeast,
organ meats (e.g., liver, kidneys), legumes (e.g., dried beans, peas, and
soybeans), meat extracts, consommé, gravies, mushrooms, spinach, asparagus,
cauliflower, and poultry.
Protein Restriction.
Diets high in protein,
particularly animal protein, increase uric acid. Although few studies have
been conducted and none of determined the value of reducing protein, one study
of gout patients suggested that eating tofu,
which is made from soy and is a source of complete protein, may be a better
choice than meats.
Maintain Healthy Weight.
A supervised weight-loss program
may, however, be a more effective way to reduce uric acid levels if the
patient is overweight. Crash dieting, on the other hand, is counterproductive
because it can increase uric acid levels and can cause an acute attack.
Maintain Fluids and Avoid Alcohol.
Drinking plenty of water and
other nonalcoholic beverages helps remove MSU crystals from the body. Heavy
drinking, especially binge drinking of beer or distilled spirits, should be
avoided, because alcohol is a source of purines and can also cause
overproduction and underexcretion of uric acid.
Avoid Joint Injury.
People with gout
should also attempt to identify and avoid activities that cause repetitive
joint trauma, such as the wearing of tight shoes.