Darvon - General Information
A narcotic analgesic structurally related to methadone. Only the dextro-isomer has an analgesic effect; the levo-isomer appears to exert an antitussive effect. [PubChem]
Pharmacology of Darvon
Darvon, a synthetic opiate agonist, is structurally similar to methadone. The analgesic effect of propoxyphene is due to the d-isomer, dextropropoxyphene. It binds to the opiate receptors and leads to a decrease of the perception of pain stimuli.
Darvon for patients
PROPOXYPHENE - ORAL
IMPORTANT NOTE: The following information is intended to supplement, not substitute for, the expertise and judgment
of your physician, pharmacist or other healthcare professional. It should not be construed to indicate that use of
the drug is safe, appropriate, or effective for you. Consult your healthcare professional before using this drug.
PROPOXYPHENE - ORAL
COMMON BRAND NAME(S): Darvon, Darvon-N
WARNING: Propoxyphene should be used with extreme caution, if at all, in people who use alcohol; have a history of
substance abuse or emotional conditions; or who already take drowsiness-causing drugs (e.g., antidepressants,
barbiturates, muscle relaxants, pain relievers, sedatives). Fatalities have occurred in such patients when propoxyphene
Patients must not take more propoxyphene than prescribed.
This medication is used to relieve moderate to severe pain.
HOW TO USE:
To prevent upset stomach, take with food or milk.
Pain medications work best in preventing pain before it occurs. Once the pain becomes intense, the medication is not as
effective in relieving it.
Use this medication exactly as directed by your doctor. Do not increase your dose, use it more frequently or use it for
a longer period of time than prescribed because this drug can be habit-forming. Also, if used for an extended period, do
not suddenly stop using this drug without your doctor's approval.
Over time, this drug may not work as well. Consult your doctor if this medication is not relieving the pain sufficiently.
May cause constipation, lightheadedness, dizziness, drowsiness, stomach upset, nausea, flushing or vision changes. If
these effects persist or worsen, inform your doctor.
Notify your doctor if you develop: irregular heartbeats, anxiety, tremors, confusion, depression, low blood pressure,
fainting, yellowing of the eyes or skin, seizures.
In the unlikely event you have an allergic reaction to this drug, seek immediate medical attention. Symptoms of an allergic
reaction include: rash, itching, swelling, dizziness, trouble breathing.
If you notice other effects not listed above, contact your doctor or pharmacist.
Tell your doctor your medical history, especially of: kidney or liver disease, breathing problems, alcohol and/or drug abuse,
colitis or other intestinal/stomach problems, severe diarrhea, head injury, heart problems, drug allergies.
Use caution when engaging in activities requiring alertness such as driving. Limit alcohol intake because it may add to the
dizziness/drowsiness effects of this medication.
Caution is advised when using this drug in the elderly because they may be more sensitive to the effects of the drug.
This medication should be used during pregnancy only when clearly needed. Discuss the risks and benefits with your doctor.
This medication is excreted into breast milk. Though to date, no problems have been noted in nursing infants, consult your
doctor before breast-feeding.
Tell your doctor of all the medicines you may use both prescription and nonprescription, especially of: carbamazepine,
cimetidine, ritonavir, other narcotic pain medications, sedatives, tranquilizers, drugs used for anxiety or depression.
Do not start or stop any medicine without doctor or pharmacist approval.
If overdose is suspected, contact your local poison control center or emergency room immediately. US residents can call
the US national poison hotline at 1-800-222-1222. Canadian residents should call their local poison control center directly.
Symptoms of overdose may include cold and clammy skin, low body temperature, slowed breathing, slowed heartbeat, drowsiness,
dizziness, lightheadedness, deep sleep, and loss of consciousness.
Do not share this medication with others.
If you miss a dose, take as soon as remembered; do not take if it is almost time for the next dose, instead, skip the missed
dose and resume your usual dosing schedule. Do not "double-up" the dose to catch up.
Store at room temperature away from sunlight and moisture.
As is the case with many medicinal agents, propoxyphene may slow the metabolism of a concomitantly administered drug. Should this occur, the higher serum concentrations of that drug may result in increased pharmacologic or adverse effects of that drug. Such occurrences have been reported when propoxyphene was administered to patients on antidepressants, anticonvulsants, or warfarin-like drugs. Sever neurologic signs, including coma, have occurred with concurrent use of carbamazepine.
Hypersensitivity to propoxyphene.
Additional information about Darvon
Darvon Indication: For the relief of mild to moderate pain
Mechanism Of Action: Darvon acts as a weak agonist at OP1, OP2, and OP3 opiate receptors within the central nervous system (CNS). Darvon primarily affects OP3 receptors, which are coupled with G-protein receptors and function as modulators, both positive and negative, of synaptic transmission via G-proteins that activate effector proteins. Binding of the opiate stimulates the exchange of GTP for GDP on the G-protein complex. As the effector system is adenylate cyclase and cAMP located at the inner surface of the plasma membrane, opioids decrease intracellular cAMP by inhibiting adenylate cyclase. Subsequently, the release of nociceptive neurotransmitters such as substance P, GABA, dopamine, acetylcholine, and noradrenaline is inhibited. Opioids such as propoxyphene also inhibit the release of vasopressin, somatostatin, insulin, and glucagon. Opioids close N-type voltage-operated calcium channels (OP2-receptor agonist) and open calcium-dependent inwardly rectifying potassium channels (OP3 and OP1 receptor agonist). This results in hyperpolarization and reduced neuronal excitability.
Drug Interactions: Anisindione Darvon increases the anticoagulant effect
Acenocoumarol Darvon increases the anticoagulant effect
Dicumarol Darvon increases the anticoagulant effect
Warfarin Darvon increases the anticoagulant effect
Atomoxetine The CYP2D6 inhibitor could increase the effect and toxicity of atomoxetine
Carbamazepine Darvon increases the effect of carbamazepine
Cimetidine Cimetidine increases the effect of the narcotic
Naltrexone Naltrexone may precipitate a withdrawal syndrome in opioid-dependent individuals
Ritonavir Ritonavir increases the levels of analgesic
Food Interactions: Not Available
Generic Name: Propoxyphene
Synonyms: D-Propoxyphene; Dextropropoxyphene; Dextropropoxyphene-M; Dextroproxifeno; Propoxyphene HCl
Drug Category: Narcotics; Antitussives; Analgesics
Drug Type: Small Molecule; Illicit; Approved
Other Brand Names containing Propoxyphene: Algafan; Antalvic; Darvon; Darvon-N; Deprancol; Depromic; Dolene; Dolocap; Doloxen; Doloxene; Erantin; Femadol; Harmar; Kesso-Gesic; Propacet; Prophene 65; Propoxychel; Propoxyphene HCl 65; Proxagesic;
Absorption: Not Available
Toxicity (Overdose): Coma, respiratory depression, circulatory collapse, and pulmonary edema. Seizures occur more frequently in patients with propoxyphene intoxication than in those with opiate intoxication. LD50=230mg/kg (orally in rat, Emerson)
Protein Binding: Not Available
Half Life: 6-12 hours
Dosage Forms of Darvon: Capsule Oral
Chemical IUPAC Name: [4-dimethylamino-3-methyl-1,2-di(phenyl)butan-2-yl] propanoate
Chemical Formula: C22H29NO2
Propoxyphene on Wikipedia: https://en.wikipedia.org/wiki/Propoxyphene
Organisms Affected: Humans and other mammals