Piroxicam poisoning

Overdosage of piroxicam

A 54-year-old woman took an overdose of 1 800 mg piroxicam. She complained of nausea and abdominal pain. Endoscopy revealed multiple superficial ulcerations in the pyloric antrum and the first part of duodenum. There were no symptoms or signs from other organ system and recovery was uneventful. The highest serum concentration was 241.6 mg/l, which is about 30 times the usual therapeutic level of 5-10 mg/l.

Acute overdose due to benzydamine

Benzydamine is a nonsteroidal anti-inflammatory drug, currently available as mouthwash, aerosol, dermal cream, vaginal douche preparation, pills and otic drops. Up to now no cases of poisoning due to this drug have been reported. A 6-year-old girl with an accidental poisoning with benzydamine is described. The episode consisted of hallucinosis without other symptoms and resolved spontaneously in 17 h.

Toxic effects of nonsteroidal anti-inflammatory drugs in overdose. An overview of recent evidence on clinical effects and dose-response relationships

Nonsalicylate, nonsteroidal anti-inflammatory drugs (NSAIDs) can be divided into 4 chemical classes: acetic acids, fenamic acids, oxicams and propionic acids. Most NSAID overdoses result in a benign outcome. Of 50,614 exposures reported to poison centres in the United States in a 2-year period, 131 (0.26%) had a major outcome, with 10 deaths. Despite the generally mild effects reported in large patient series, isolated case reports have documented serious toxicity, such as seizures, hypotension, apnoea, coma and renal failure. The majority of these consequences occur after ingestion of substantial quantities by adults attempting suicide. Rarely, with ibuprofen and piroxicam, children who ingest small amounts in accidental exposure develop serious toxicity. Typical signs and symptoms of NSAID overdose include nausea, vomiting, headache, drowsiness, blurred vision and dizziness. Seizures are rarely documented across all NSAID classes, with the exception of mefenamic acid (where seizures occur in over one-third of cases), or following massive ingestion of other agents. Drugs in the propionic acid group have produced metabolic acidosis, respiratory depression and coma in severe cases. Ibuprofen is the agent with the most published data on overdose, probably because it is available without a prescription in many countries. Symptoms are unlikely after ingestion of 100 mg/kg or less, and are usually not life-threatening unless more than 400 mg/kg is ingested. There is some relationship between plasma concentrations and the potential for development of symptoms, but plasma concentrations have no impact on treatment decisions. Treatment of NSAID overdose is entirely supportive. Recent trends in emergency department procedures regarding gastric decontamination are evolving towards the recommended administration of activated charcoal without gastric emptying in patients presenting more than 1 hour after ingestion, although gastric lavage, followed by administration of activated charcoal, may be advisable in patients who present earlier. Home administration of syrup of ipecac is still recommended if treatment is given shortly after ingestion, with a few exceptions: for example, ipecac is contraindicated after ingestion of mefenamic acid or ibuprofen in amounts greater than 400 mg/kg. Urine alkalinisation and diuresis have been recommended to enhance the elimination of NSAIDs, based on a pKa in the range of 3 to 5. However, because the drugs are universally highly protein bound, with little unchanged renal excretion, this technique is not likely to be beneficial. Haemodialysis is also unlikely to enhance elimination, but may be required if oliguric renal failure develops. Multiple dose activated charcoal may be useful in enhancing elimination of NSAIDs with long half-lives, such as piroxicam and sulindac.

Rapid high-performance liquid chromatographic methods for the determination of overdose concentrations of some non-steroidal anti-inflammatory drugs in plasma or serum

Separate methods are described for the determination of the non-steroidal anti-inflammatory drugs diflunisal, indomethacin, fenoprofen, ibuprofen, ketoprofen, naproxen, mefenamic acid and piroxicam at overdose concentrations in human plasma or serum, using high-performance liquid chromatography and ultraviolet detection. A common extraction, involving protein precipitation with acetonitrile, is employed for all methods. A 25 cm Hypersil ODS (5 mu particle size) analytical column is used for all chromatographic separations, with a mobile phase of acetonitrile-acetate buffer (pH 4.2 or 4.8). The methods are all reproducible and can also determine concentrations that fall within the normal therapeutic range for each drug.

Changes in body temperature after administration of antipyretics, LSD, delta 9-THC and related agents: II

Antipyretics, in particular acetaminophen, aspirin and ibuprofen, constitute the single most important class of drugs used therapeutically for an effect on body temperature. Hallucinogens exert prominent actions on the central nervous system, and it is not surprising that, like so many other centrally-acting agents, they too often affect temperature. This compilation primarily covers the considerable amount of data published from 1981 through 1985 on the interactions of these drugs and thermoregulation, but data from many earlier papers not included in a previous compilation are also tabulated. The effects of agents not classically considered as antipyretics on temperatures of febrile subjects are also covered. The information listed includes the species used, the route of administration and dose of drug, the environmental temperature at which experiments were performed, the number of tests, the direction and magnitude of change in body temperature and remarks on special conditions, such as age or brain lesions. Also indicated is the influence of other drugs, such as antagonists, on the response to the primary agent.

Non-narcotic analgesics. Problems of overdosage

The first cases of fulminant hepatic failure due to paracetamol poisoning were reported in 1966, and in the United Kingdom this condition is now responsible for more cases of acute hepatic failure than any other cause. Adults account for the majority of serious and fatal cases of paracetamol poisoning and it is extremely rare for young children to ingest sufficient paracetamol to cause more than minimal liver damage. A single measurement of the plasma paracetamol concentration is an accurate predictor of liver damage provided that it is taken not earlier than 4 hours after ingestion of the overdose. Peak disturbance of liver function occurs 2 to 4 days after the overdose, often accompanied by mild jaundice, after which recovery is usually rapid and complete. In a few patients, fulminant hepatic failure, manifested by increasing jaundice and encephalopathy, may develop by the third to fifth day. Acute renal failure may complicate paracetamol poisoning, often in the context of severe liver damage. Renal failure, which is often non-oliguric, typically becomes apparent 24 to 72 hours after overdosage. The treatment of paracetamol intoxication should include gastric lavage, which has been shown to be of value for up to 6 hours after ingestion of a paracetamol overdose. Further general treatment may include parenteral fluid replacement and a prophylactic infusion of dextrose (5-10%) in patients at risk of hepatic failure. Specific protective agents in those patients at risk of paracetamol-induced liver damage include N-acetylcysteine and methionine which are most effective if given within 8 to 10 hours of ingestion of the overdose. Hepatic and renal failure should be managed conventionally. In recent years in the United Kingdom there has been a gradual decline in the number of hospital admissions and the number of deaths from aspirin poisoning. Salicylates in overdose directly stimulate the respiratory centre and so cause a respiratory alkalosis. Metabolic acidosis occurs in severe poisoning because of impairment of the oxidative metabolism of energy substrates. At very high salicylate concentrations respiratory depression may occur, possibly associated with neuroglycopenia, adding respiratory acidosis to the worsening metabolic acidosis. In addition to a mixed acid-base disturbance, hypokalaemia and hypoglycaemia may be present. Nausea and vomiting increase the fluid deficit. If dehydration is sufficiently severe, decreasing cardiac output may hasten development of lactic acidosis and acute renal failure.(ABSTRACT TRUNCATED AT 400 WORDS)

Piroxicam. A reappraisal of its pharmacology and therapeutic efficacy

Piroxicam is a chemically different non-steroidal anti-inflammatory drug with a long half-life which enables it to be administered once daily. This member of the oxicam series of compounds is now well established in the treatment of rheumatoid arthritis and osteoarthritis and has been shown to be a suitable alternative to aspirin, indomethacin, naproxen, ibuprofen, ketoprofen, sulindac, phenylbutazone and diclofenac in the treatment of rheumatic diseases. Open trials in many thousands of patients in hospital clinics and in general practice have demonstrated its analgesic and anti-inflammatory efficacy in a wide cross-section of patients with rheumatic diseases, when administered once daily either at night or in the morning, and recent studies have demonstrated its usefulness in musculoskeletal disorders, dysmenorrhoea and postoperative pain. Such studies have also demonstrated the generally good tolerability of piroxicam 20mg daily. As with other non-steroidal anti-inflammatory drugs, gastrointestinal complaints are the most frequently reported side effects. The frequency and severity of these effects are dose related. Thus, piroxicam is now well established in the treatment of rheumatic diseases and offers an alternative to other analgesics in various pain states.