Pharm Arthritis And Gout Part 2

Explanation
The signs and symptoms of the patient indicate that he is suffering from salicylate overdose toxicity.
Even if salicylates have an antipyretic action they can cause hyperthermia when given in too high doses. --This seems mainly due to the uncoupling of oxidative phosphorylation in skeletal muscle, that is oxidation proceeds without phosphorylation so producing heat.
This action is quite similar to that produced by dinitrophenol.
A, B, C, E) All these are actions of salicylates but have nothing to do with salicylate induced
hyperthermia.

Explanation
The symptoms and signs of the patient suggest that he is suffering from an acute gouty attack.
Indomethacin is commonly prescribed for the treatment of acute attack of gout and many
consider it to be the drug of choice. Colchicine is another drug highly effective in the gouty
attack, but is less frequently used today because of its potential adverse effects.
A) The analgesic action of propoxyphene (an opioid analgesic) is too weak to be useful in the
gouty attack.
C) Gold compounds are useful in rheumatoid arthritis but are without effect in gouty arthritis.
D) NSAIDs other than indomethacin have been proved effective in the treatment of acute gouty
arthritis. Aspirin however can inhibit (when given in small doses) the excretion of uric acid by
the kidney and therefore should not be used for analgesia in patients with gout.
E, F) These drugs can decrease uric acid plasma levels in patients with gout but they cannot
relieve the pain of a gouty attack.

Explanation
In man uric acid is filtered by the glomerulus and 98% is reabsorbed in the proximal tubule by a
brush border transporter. The remaining 2% makes up about 20% of the uric acid eliminated by
the kidney. The remaining comes from tubular secretion by an active transport system that
eliminates organic acid. Uricosuric drugs like probenecid and salicylates compete with uric acid
for these transport mechanisms. They have a paradoxical effect because, depending on
dosage, they may either decrease or increase the elimination of uric acid. It seems that the
secretory mechanism is more sensitive to the blocking action of uricosuric drugs, so low doses
can block uric acid secretion only. Higher doses are able to block both mechanisms and
therefore, since most of the uric acid is reabsorbed, the net results is an increased elimination.
Salicylates like aspirin can completely antagonize the uricosuric action of probenecid. This
interaction probably involves several mechanisms including competition for renal tubular
transport.
A, B, C, E) (see explanation above)

Explanation
Chronic use (6-8 months, or more) of antipyretic analgesics can cause a nephropathy which is
characterized by renal papillary necrosis (the primary lesion) and chronic interstitial nephritis.
The cause of the disease is still uncertain but it seems related to the chronic inhibition of
prostaglandin biosynthesis. The risk increases with the use of analgesic combinations, like in
the present case.
A, B, D, E, F) (see explanation above)

Explanation
The results of the autopsy and the history of the patient suggest that the cause of death was Reye’s syndrome. The syndrome consists of an acute encephalopathy with fatty degeneration of the viscera. It is usually seen in children and lethality is estimated to be about 20 %.
The cause of the syndrome is unknown, but risk factors involve viral infection and use of salicylates, like in the present case.
The prevalence of Reye’s the syndrome is very low (about 1:100000) but the use of salicylates during a viral illness increases risk for developing the syndrome by as much as 35 fold.
A, B, C, E, F) These drugs do not cause the Reye’s syndrome.

Explanation
The symptoms and the history of the patient suggest that he is affected by iron deficiency
anemia. In adult males the most common causes of iron deficiency anemias is chronic occult
bleeding, which is present in more than 70 % of patients chronically treated with salicylates.
Iron deficiency from inadequate diet can also contribute to the anemia, like in the present case
(the man was vegetarian).
B, C, D, E) (see explanation above)

Explanation
Poisoning from acetaminophen is due to toxic metabolites (mainly N-acetyl parabenzoquinone)
that accumulate when glutathione is not available for conjugation. In the
absence of glutathione these toxic metabolites react with cellular proteins, resulting in
hepatotoxicity. This occurs after the ingestion of toxic doses or when alcohol is taken together
with acetaminophen, since in both cases glutathione is depleted faster than it can be
generated.
The alcohol-acetaminophen syndrome occurs in a clinical setting in which acute, sometimes
fulminant, hepatic necrosis develops after large doses of acetaminophen are taken during an
alcoholic binge or a period of chronic, excessive alcohol intake. Peculiar to the alcoholacetaminophen
syndrome are the extremely high serum transaminase levels. Early treatment
consists of the administration of N-acetylcysteine, although at 48 hours or more after the
ingestion its use remains controversial.
A, B, D, E) Overdose of all the other listed drugs does not cause a high increase in serum
transaminase levels.

Explanation
The symptoms of the patient, the marked hyperthermia and the respiratory depression suggest
severe poisoning by salicylates. This is supported by the lab results indicating mixed
respiratory and metabolic acidosis (low pH, increased PCO2 and decreased plasma
bicarbonate content). This acid-base disturbance is typical of a high salicylate content in blood.
In salicylate poisoning, the initial event (when salicylate concentration in blood is not yet high) is
respiratory alkalosis caused by salicylate-induced stimulation of respiratory center. Partial
compensation is achieved, as usual, by increased renal excretion of bicarbonate. Therefore the
initial phase of poisoning (or when the poisoning is mild) is characterized by high pH, and
decreased plasma levels of PCO2 and bicarbonate. In a later phase, when salicylate blood
levels become quite high, the respiratory center becomes depressed and respiratory acidosis
supervenes. This acidosis is uncompensated since a significant amount of bicarbonate has
been already eliminated. Moreover salicylate causes uncoupling of mitochondrial oxidative
phosphorylation (which leads to hyperthermia) and inhibits the enzymes of Krebs cycle,
resulting in increased pyruvic and lactic acids. Lipolysis, gluconeogenesis and glycolysis also
are stimulated, leading to hyperglycemia and production of keto acids. Therefore the final
picture is the one of mixed respiratory and metabolic acidosis.
A) Acute alcohol poisoning can cause combative behavior, but hypothermia and hypoglycemia,
are typical signs of alcohol poisoning and tinnitus is usually absent.
B, C, D) Poisoning by NSAIDs other than salicylates does not usually cause profound
impairment of acid-base balance.

Explanation
Normally renal blood flow is maintained by a balance between renal vasoconstrictors
(angiotensin II, norepinephrine) and renal vasodilators (prostaglandin E, prostacyclin). In
cardiac failure circulating angiotensin II and norepinephrine are increased. In this setting the
administration of a NSAID can remove renal vasodilator influences and result in
profound vasoconstriction. In addition it has been shown that NSAIDs inhibit the diuretic
effect of most diuretic agents, which explains why even an increase in furosemide dosage had
no effect.
B) Worsening of cardiac failure can be associated with oliguria, but this is unlikely in the
present case since the patient did show improvement with therapy.
C) Furosemide can increase angiotensin II secretion, secondary to the inhibition of NA+ and Cltransport
into the macula densa, but this in turn normally stimulates prostaglandin secretion so
that the final effect of furosemide is usually vasodilation of renal vascular bed.
D) Oliguria is not a prominent sign of digoxin toxicity
E) Severe hypokalemia impairs the concentrating ability of the kidney and therefore tend to
cause polyuria, not oliguria.

Explanation
Primary dysmenorrhea is a cyclic pain associated with menses during ovulatory cycles, but
without demonstrable lesions affecting the reproductive cycle. The pain is thought to results
from uterine contraction and ischemia, most likely mediated by the actions of prostaglandins
produced by the secretory endometrium. NSAIDs taken 2 days before menses and continued
2-3 days thereafter, represent the drugs of choice. Propionic acid derivatives appears to be
very effective since good to complete pain relief was reported for 42 to 100% of women using
ibuprofen, in many clinical trials.
A) Even if acetaminophen is advertised as an analgesic for dysmenorrhea, it is much less
effective
than NSAIDs because it is a very poor inhibitor of cyclooxygenase in peripheral tissues.
B) Beta-2 agonists can relax the uterus but their action is much less effective than that of
NSAIDs in dysmenorrhea where prostaglandins play the main role.
C, D, E; G) These drugs actually would increase, not decrease, uterine contractions.

Explanation
The signs and symptoms of the boy strongly suggest that he has a patent ductus arteriosus,
which can occur in up to 80% of premature infants with a birth weight less than 1200 g. In
uterus patency of ductus arteriosus is maintained by the low Po2 and by the high concentration
of prostaglandins, mainly PGE1, PGE2 and PGI2, which have vasodilatory actions. Because of
this, NSAIDs have been found to speed up the closure of ductus arteriosus in newborn babies.
Indomethacin given IV is the treatment of choice and can achieve the closure in more than
70% of neonates.
A) Actually alprostadil (PGE1) can maintain the patency of ductus arteriosus and is sometimes
used for this purpose in neonates with congenital heart disease, until surgery can be
performed.
B, D, E, F) These drug have no effect on patency of ductus arteriosus.

Explanation
The symptoms and the history of the patient suggest that the pain is caused by bone
metastases that are the most frequent metastases in case of prostatic carcinoma. Osseous
metastases induce an inflammatory reaction with the production of prostaglandins that may
cause osteolysis and sensitize free nerve ending so augmenting pain perception. The NSAIDs
effectively decrease prostaglandin and endoperoxide production and therefore can be useful
for an initial treatment of metastatic bone pain. Piroxicam is a long-acting, nonselective
competitive inhibitor of cyclooxygenase that also inhibits polymorphonuclear cell migration and
decreases oxygen radical production. Likely all NSAIDs would be useful, and the superiority of
any particular drug for a particular patient cannot be predicted. Therefore the initial choice is
often based on specific patient related contraindications. In fact in this patient:
A) Aspirin is contraindicated because of his congenital G6PD deficiency (salicylates can cause
hemolytic anemia in patients with this deficiency)
B) Acetaminophen is a very weak inhibitor of cyclooxygenase in the presence of a high
concentration of peroxide that are found in inflammatory lesions.
D) All propionic acid derivatives are contraindicated because of the serious allergic reaction to
naproxen.
E) Propoxyphene is a very weak opioid analgesic that would be less effective in bone
metastases where the pain is mainly related to the inflammatory reaction.
F) Tricyclic antidepressant like amitriptyline are sometime useful analgesics in neoplastic
disorders when the pain is neuropathic (i.e. due to the damage of neuronal structures) but mot
so when the pain is nociceptive (i.e. pain transmitted over intact neural pathways) like in the
present case.

Explanation
Ibuprofen has been approved for use as an antipyretic in children and is currently available
over the counter. All NSAIDs have antipyretic activity and therefore the initial choice is often
based on specific patient related contraindications. In fact in this patient:
A) Aspirin is contraindicated because of the risk of Reye’s syndrome. This serious disorders
affects mainly children or young adults and predisposing factors include salicylate therapy.
B) Indomethacin is not indicated for general use as analgesic or antipyretic because of its
toxicity.
C) Acetaminophen is contraindicated in this patient because of his congenital deficiency of
RBC glutathione synthase. Acetaminophen is partially metabolized to N-acetyl-p-benzoquinone
which is rapidly conjugated with glutathione. If glutathione stores are deficient, the metabolite
reacts with hepatocyte macromolecules, resulting in hepatotoxicity. Patients with congenital
deficiency of glutathione synthase are therefore at increased risk of acetaminophen toxicity.
E, F) These drugs are not used as antipyretics.

Explanation
Since the patient is suffering from hemophilia all NSAIDs are contraindicated since they can
decrease platelet aggregation and can provoke gastrointestinal bleeding. Acetaminophen is
free from the above mentioned effects and can be use as analgesic in this patient.
A, C, D, E, F) (see explanation above)

Explanation
Celecoxib is a selective inhibitor of cyclooxygenase 2. Drugs of this class (sometimes called
oxibs) have analgesic, antipyretic and antiinflammatory actions. However their lack action on
platelet aggregation and have minimal adverse effects on gastric mucosa. These drugs are
therefore preferred in patients at risk of peptic ulcer disease, like in the present case.
A, B, C, D, F) (see explanation above)

Explanation
NSAIDs offer mainly a symptomatic relief in rheumatoid arthritis, but have little effect on the
progression of bone and cartilage destruction. Drugs that may slow this progression (by
reducing joint inflammation and preventing joint damage) are called disease-modifying
antirheumatic drugs (DMARDS) and include some antimalarial drugs (chloroquine and
hydroxychloroquine), gold compounds, sulfasalazine, and several immunosuppressant drugs
(including glucocorticoids). These drugs are slow acting antiinflammatory agents and the effect
may take 2-6 months to become apparent. Their mechanism of action is still uncertain, but they
are often useful as adjuncts to treatment with NSAIDs. The symptoms of the patient indicate an
initial retinopathy, a rare adverse effect of several antimalarial drugs after long term treatment.
A, B, C, E, F) All these drugs can be used in rheumatoid arthritis but they do not cause retinal
damage.

Explanation
Since urate levels are decreased after therapy both in plasma and in the urine, the drug must
have decreased the formation of uric acid. Allopurinol inhibits the conversion of hypoxanthine to
xanthine and xanthine to uric acid, so decreasing uric acid formation.
A) Probenecid increases the renal excretion of uric acid and would have decreased uric acid in
plasma but would have increased uric acid in the urine (so causing uricosuria).
B) Aspirin would have decreased uric acid secretion at low/intermediate doses (so causing
hyperuricemia) and would have increased secretion at high doses (so causing uricosuria).
C) Furosemide can cause hyperuricemia.
E, F) These drugs have negligible effects on uric acid secretion.

Explanation
The patient has hyperuricemia that was likely the cause of renal calculi, which could have played a
role (intrarenal precipitation of urates) in the border-line renal insufficiency (elevated BUN). Drugs
that decrease uric acid formation (allopurinol) or that increase uric acid secretion (probenecid) can
be used to treat hyperuricemia.
A) In this patient, however, probenecid is contraindicated because an increased concentration of
uric acid in the urine could favor the formation of urate calculi.
B, C) These diuretics are contraindicated because they tend to cause hyperuricemia.
E) Indomethacin is used to treat acute gout but is not effective against hyperuricemia

Explanation
The patient most likely had the tumor lysis syndrome which develops following the institution of
systemic chemotherapy for rapidly growing bulky tumors. The syndrome is most often observed in
patients with certain types of lymphoma (acute lymphoblastic, diffuse undifferentiated, Burkitt’s) or
acute lymphocytic leukemia. Rapid lysis of tumor leads to release of intracellular uric acid,
potassium and phosphate with resultant hyperuricemia, hyperkalemia, hyperphosphatemia and
hypocalcemia (secondary to calcium and phosphate precipitation in the presence of an elevated
serum phosphorus). Renal failure may result from uric acid and /or calcium phosphate deposition
in the renal tubules. In the present patient, since serum phosphorus and calcium are normal, renal
failure (which is also indicated by the high creatinine and BUN values) is most likely due to urate
precipitation in renal tubules. All patients undergoing intensive chemotherapy should be pretreated
with allopurinol to prevent hyperuricemia. All the other listed drugs cannot prevent hyperuricemia
and moreover they are all contraindicated because:
A) Hydrochlorothiazide can cause hyperuricemia.
B) Spironolactone can cause hyperkalemia.
C) Furosemide can cause hypocalcemia.
D) Probenecid would increase urate excretion and therefore the risk of urate precipitation in renal
tubules.

Explanation
The signs and the history of the patient suggest that she was treated with a gold compound. These
agents are employed in the treatment of rheumatoid arthritis in an attempt to arrest the progress of
the disease and to induce remission. Gold compounds cause a high incidence of toxicity. The
most common adverse effect (which occur in 15-20 % of patients) involve the skin and mucous
membranes, usually the mouth. A gray-to-blue pigmentation may also occur in the skin, like in the
present case. Kidney function may also be affected in about 10% of patient.
B, C, D, E, F) All these drugs can be used in rheumatoid arthritis but they do not cause the pattern
of adverse effect presented by the patient.