Product Information
Registration Status: ActiveDURO-TUSS DECONGESTANT LINCTUS is approved to be sold in Singapore with effective from 1994-02-02. It is marketed by INOVA PHARMACEUTICALS (SINGAPORE) PTE LTD, with the registration number of SIN07631P.
This product contains Pholcodine 15mg/15ml, and Pseudoephedrine 60mg/15ml in the form of ELIXIR. It is approved for ORAL use.
This product is manufactured by INOVA PHARMACEUTICALS (AUSTRALIA) PTY LTD in AUSTRALIA.
It is a Pharmacy Only Medicine that can be obtained from a pharmacist at a retail pharmacy.
Description
Pholcodine formula is 3-o-morpholinoethylmorphine and it is classified as an antitussive which is defined as an opioid cough suppressant. It belongs to the opioid family of compounds and it is widely used.[A31738] Pholcodine activity is the suppression of unproductive cough and it also has a mild sedative effect with little or no analgesic effects.[A31742] Pholcodine is not prescribed in the United States where it is classed as a Schedule I drug. It is categorized as Class B drug in the UK and officially taken out of the shelves in 2008. Pholcodine is not approved in Canada.
Indication
Pholcodine is indicated as a cough suppressant for the temporary relief of non-productive dry cough. It is stated to present a required label indication of "temporary relief of dry cough."[L1200] Cough is the respiratory movement that occurs after an irritation signal is transmitted to the central nervous system and further stimulates the medulla oblongata. This stimulation causes a motor output that is sent through motoneurons to the respiratory muscles. A non-productive cough is a type of cough characterized by the absence of sputum, and it has a large inspiration that will cause continuous coughing.
Mechanism of Action
The mechanism of action of pholcodine is directly performed in the medulla oblongata. In this site, it exerts analgesic properties on the peripheric reflexogenic receptors. This site is commonly known as the "cough center."[L1202]
Pharmacokinetics
- Absorption
- After oral administration of 60 mg of pholcodine, the Tmax and Cmax are reported to be 1.3 hours and 26.3 ng/ml. In the same administration, the AUC in plasma and saliva are reported to be 1.67 and 6.61 mg h/l respectively. The absorption of pholcodine is reported to represent approximately 88% of the administered dose.[A31738]
- Distribution
- The reported volume of distribution depends on the pharmacokinetic model and it can be of 265L based on a one-compartment model to 3207L in a two-compartment model.[A31747]
- Metabolism
- The metabolism of pholcodine seems to be very slow[A31747] and due to the elimination profile, it is thought that most of the administered dose undergoes metabolism. There is some evidence in preclinical trials that indicate that morphine is a minor metabolite of pholcodine and that it accounts for 1% of the administered dose.[A31738]
- Elimination
Clearance
After oral administration of 60 mg of pholcodine, the clearance rate was reported to be 126 ml/min.[A31738]
Toxicity
Generally, pholcodine is significantly less toxic than codeine. Nonetheless, it is important to consider the significant depressive respiratory effect.[L1202]
Active Ingredient/Synonyms
Pholcodine | Pholcodine |
Source of information: Drugbank (External Link). Last updated on: 3rd July 18. *Trade Name used in the content below may not be the same as the HSA-registered product.
Description
An alpha- and beta-adrenergic agonist that may also enhance release of norepinephrine. It has been used in the treatment of several disorders including asthma, heart failure, rhinitis, and urinary incontinence, and for its central nervous system stimulatory effects in the treatment of narcolepsy and depression. It has become less extensively used with the advent of more selective agonists.
Indication
For the treatment of nasal congestion, sinus congestion, Eustachian tube congestion, and vasomotor rhinitis, and as an adjunct to other agents in the optimum treatment of allergic rhinitis, croup, sinusitis, otitis media, and tracheobronchitis. Also used as first-line therapy of priapism.
Mechanism of Action
Pseudoephedrine acts directly on both alpha- and, to a lesser degree, beta-adrenergic receptors. Through direct action on alpha-adrenergic receptors in the mucosa of the respiratory tract, pseudoephedrine produces vasoconstriction. Pseudoephedrine relaxes bronchial smooth muscle by stimulating beta2-adrenergic receptors. Like ephedrine, pseudoephedrine releasing norepinephrine from its storage sites, an indirect effect. This is its main and direct mechanism of action. The displaced noradrenaline is released into the neuronal synapse where it is free to activate the postsynaptic adrenergic receptors.
Pharmacokinetics
- Absorption
- Pseudoephedrine is readily and almost completely absorbed from the GI tract and there is no evidence of first-pass metabolism.
- Distribution
- Metabolism
- Hepatic.
- Elimination
Toxicity
Common adverse reactions include nervousness, restlessness, and insomnia. Rare adverse reactions include difficult/painful urination, dizziness/lightheadedness, heart palpitations, headache, increased sweating, nausea/vomiting, trembling, troubled breathing, unusual paleness, and weakness.
Active Ingredient/Synonyms
(+) threo-2-(methylamino)-1-phenyl-1-propanol | (+)-(1S,2S)-Pseudoephedrine | (+)-Pseudoephedrine | (+)-psi-Ephedrine | (+)-threo-Ephedrine | d-Isoephedrine | d-Pseudoephedrine | d-psi-2-Methylamino-1-phenyl-1-propanol | d-psi-Ephedrine | Isoephedrine | L-(+)-Pseudoephedrine | L(+)-psi-Ephedrine | Pseudoefedrina | pseudoéphédrine | Pseudoephedrine D-form | Pseudoephedrinum | Psi-ephedrin | Psi-ephedrine | trans-Ephedrine | ψ-ephedrine | Pseudoephedrine |
Source of information: Drugbank (External Link). Last updated on: 3rd July 18. *Trade Name used in the content below may not be the same as the HSA-registered product.