DrugLib.com — Drug Information Portal

Rx drug information, pharmaceutical research, clinical trials, news, and more

Darvon-N (Propoxyphene Napsylate) - Drug Interactions, Contraindications, Overdosage, etc

 
 



DRUG INTERACTIONS

DARVON-N drug label information in our database does not contain a dedicated section on drug interactions. Please check subsections of WARNINGS AND PRECAUTIONS as well as other sources.

OVERDOSAGE

Overdose of Darvon-N may present with the signs and symptoms of propoxyphene overdose. Fatalities within the first hour of overdosage are not uncommon.

In all cases of suspected overdosage, call your regional Poison Control Center to obtain the most up-to-date information about the treatment of overdose. This recommendation is made because, in general, information regarding the treatment of overdosage may change more rapidly than do package inserts.

Initial consideration should be given to the management of the CNS effects of propoxyphene overdosage. Resuscitative measures should be initiated promptly.

Symptoms of Propoxyphene Overdosage

The manifestations of acute overdosage with propoxyphene are those of narcotic overdosage. The patient is usually somnolent but may be stuporous or comatose and convulsing. Respiratory depression is characteristic. The ventilatory rate and/or tidal volume is decreased, which results in cyanosis and hypoxia. Pupils, initially pinpoint, may become dilated as hypoxia increases. Cheyne-Stokes respiration and apnea may occur. Blood pressure and heart rate are usually normal initially, but blood pressure falls and cardiac performance deteriorates, which ultimately results in pulmonary edema and circulatory collapse, unless the respiratory depression is corrected and adequate ventilation is restored promptly. Cardiac arrhythmias and conduction delay may be present. A combined respiratory-metabolic acidosis occurs owing to retained CO2 (hypercapnia) and to lactic acid formed during anaerobic glycolysis. Acidosis may be severe if large amounts of salicylates have also been ingested. Death may occur.

Treatment of Propoxyphene Overdosage

Attention should be directed first to establishing a patent airway and to restoring ventilation. Mechanically assisted ventilation, with or without oxygen, may be required, and positive pressure respiration may be desirable if pulmonary edema is present. The opioid antagonist naloxone will markedly reduce the degree of respiratory depression, and should be administered promptly, preferably intravenously. The duration of action of the antagonist may be brief. If no response is observed after 10 mg of naloxone have been administered, the diagnosis of propoxyphene toxicity should be questioned.

In addition to the use of an opioid antagonist, the patient may require careful titration with an anticonvulsant to control convulsions. Activated charcoal can adsorb a significant amount of ingested propoxyphene. Dialysis is of little value in poisoning due to propoxyphene. Efforts should be made to determine whether other agents, such as alcohol, barbiturates, tranquilizers, or other CNS depressants, were also ingested, since these increase CNS depression as well as cause specific toxic effects or death.

CONTRAINDICATIONS

Darvon-N is contraindicated in patients with known hypersensitivity to propoxyphene.

Darvon-N is contraindicated in patients with significant respiratory depression (in unmonitored settings or the absence of resuscitative equipment) and patients with acute or severe asthma or hypercarbia.

Darvon-N is contraindicated in any patient who has or is suspected of having paralytic ileus.

DRUG ABUSE AND DEPENDENCE Controlled Substance

Darvon-N is a Schedule IV narcotic under the U.S. Controlled Substances Act. Darvon-N can produce drug dependence of the morphine type, and therefore, has the potential for being abused. Psychic dependence, physical dependence and tolerance may develop upon repeated administration. Darvon-N should be prescribed and administered with the same degree of caution appropriate to the use of other narcotic-containing medications.

Abuse

Since Darvon-N is a mu-opioid agonist, it may be subject to misuse, abuse, and addiction. Addiction to opioids prescribed for pain management has not been estimated. However, requests for opioids from opioid-addicted patients occur. As such, physicians should take appropriate care in prescribing Darvon-N.

Dependence

Opioid analgesics may cause psychological and physical dependence. Physical dependence results in withdrawal symptoms in patients who abruptly discontinue the drug after long term administration. Also, symptoms of withdrawal may be precipitated through the administration of drugs with mu-opioid antagonist activity, e.g., naloxone or mixed agonist/antagonist analgesics (e.g., pentazocine, butorphanol, nalbuphine, dezocine) (see Overdosage). Physical dependence usually does not occur to a clinically significant degree, until after several weeks of continued opioid usage. Tolerance, in which increasingly larger doses are required to produce the same degree of analgesia, is initially manifested by a shortened duration of an analgesic effect and subsequently, by decreases in the intensity of analgesia.

In chronic pain patients, and in opioid-tolerant cancer patients, the administration of Darvon-N should be guided by the degree of tolerance manifested and the doses needed to adequately relieve pain.

The severity of the Darvon-N abstinence syndrome may depend on the degree of physical dependence. Withdrawal is characterized by rhinitis, myalgia, abdominal cramping, and occasional diarrhea. Most observable symptoms disappear in 5 to 14 days without treatment; however, there may be a phase of secondary or chronic abstinence which may last for 2 to 6 months characterized by insomnia, irritability, and muscular aches. The patient may be detoxified by gradual reduction of the dose. Gastrointestinal disturbances or dehydration should be treated with supportive care.

-- advertisement -- The American Red Cross
 
Home | About Us | Contact Us | Site usage policy | Privacy policy

All Rights reserved - Copyright DrugLib.com, 2006-2017