It acts on the CNS Opioid receptors. It has agonist action on mu Opioid receptors. It primarily binds to the mu Opioid receptors and produce analgesia. Its CNS effects are same as morphine. It gives in combination with other Non Steroidal Anti Inflammatory Drugs or other analgesics usually.
Pharmacokinetics
Absorption : Orally absorbed; primarily to the upper small intestine.
Distribution : Widely distributed in the body. Enters the cerebrospinal fluid and cross the placenta.
Metabolism : In liver it is metabolized by N-demethylation. Norpropoxyphene is its active metabolite. It has more half life than parent drug. It causes toxicity at sometime due to its metabolites accumulation in the body.
Excretion : It is excreted through urine.
On Set of Action
30 to 60 min. after oral administration
Duration of Action
4 to 6 hrs
Half Life
Plasma half life is 6 to 12 hrs
Adverse Effects
1. Nausea
2. Vomiting
3. Epigastric distress
4. Sedation
5. Dizziness
6. Urticaria
7. Visual disturbances
8. Physiological dependence
ContraIndications
1. Hypersensitivity to this drug
2. Respiratory depression
3. Children below 12 years
Special Precautions
1. In patients with hepatic failure or renal failure used cautiously
2. Patient can not drive or operate machinery after the drug administration. So the care should be taken
3. Use cautiously in patients with suicidal mentality
Pregnancy
Contraindicated
Breast Feeding
Use with caution
Elderly
Use with caution
Interactions
Barbiturate Anaesthetics: May increase respiratory and CNS depressive effects of propoxyphene.
Warfarin: Potentiation of hypoprothrombinemic effect.
Carbamazipine: May increase serum carbamzipine levels with resultant toxicity.
Indications
1. Relieve moderate to severe pain in various conditions
2. Opioid withdrawal
Dosage
Oral-
Adults - 65mg 3 to 4 times daily.
Others
Preparation of Narcotic Drugs Exempted from some of the provisions and which are included in Schedule III of 1961 convention (Yellow List Under International Narcotics Control Board ( ) as under
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